3705 - switch to tested file-system primitives

author: Kartik K. Agaram <vc@akkartik.com> 2016-12-11 16:18:18 -0800
committer: Kartik K. Agaram <vc@akkartik.com> 2016-12-11 16:18:18 -0800
commit: 294b2ab35983ebe95698835bb54bca8bd3eec101 (patch)
tree: fbc74bea6cefd7b8f527d36a7b7c6804dd886414 /html
parent: d5c86dfd8706e6b3ceee7843464797e6fcad4259 (diff)
download: mu-294b2ab35983ebe95698835bb54bca8bd3eec101.tar.gz
13 files changed, 602 insertions, 643 deletions
diff --git a/html/088file.mu.html b/html/088file.mu.html
index 49801745..aae7cae6 100644
--- a/html/088file.mu.html
+++ b/html/088file.mu.html
@@ -33,6 +33,13 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <pre id='vimCodeElement'>
 <span class="Comment"># Wrappers around file system primitives that take a 'resources' object and</span>
 <span class="Comment"># are thus easier to test.</span>
+<span class="Comment">#</span>
+<span class="Comment"># - start-reading - asynchronously open a file, returning a channel source for</span>
+<span class="Comment">#   receiving the results</span>
+<span class="Comment"># - start-writing - asynchronously open a file, returning a channel sink for</span>
+<span class="Comment">#   the data to write</span>
+<span class="Comment"># - slurp - synchronously read from a file</span>
+<span class="Comment"># - dump - synchronously write to a file</span>
 
 <span class="muData">container</span> resources [
   lock:bool
@@ -44,25 +51,42 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   contents:text
 ]
 
-<span class="muRecipe">def</span> start-reading resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>contents:&amp;:source:char [
+<span class="muRecipe">def</span> start-reading resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>contents:&amp;:source:char, error?:bool [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
+  error? <span class="Special">&lt;-</span> copy <span class="Constant">0/false</span>
   <span class="Delimiter">{</span>
     <span class="muControl">break-unless</span> resources
     <span class="Comment"># fake file system</span>
-    contents <span class="Special">&lt;-</span> start-reading-from-fake-resources resources, filename
+    contents, error? <span class="Special">&lt;-</span> start-reading-from-fake-resource resources, filename
     <span class="muControl">return</span>
   <span class="Delimiter">}</span>
   <span class="Comment"># real file system</span>
   file:num <span class="Special">&lt;-</span> $open-file-for-reading filename
-  assert file, <span class="Constant">[file not found]</span>
+  <span class="muControl">return-unless</span> file, <span class="Constant">0/contents</span>, <span class="Constant">1/error?</span>
   contents:&amp;:source:char, sink:&amp;:sink:char <span class="Special">&lt;-</span> new-channel<span class="Constant"> 30</span>
   start-running receive-from-file file, sink
 ]
 
-<span class="muRecipe">def</span> start-reading-from-fake-resources resources:&amp;:resources, resource:text<span class="muRecipe"> -&gt; </span>contents:&amp;:source:char [
+<span class="muRecipe">def</span> slurp resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>contents:text, error?:bool [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
+  source:&amp;:source:char, error?:bool <span class="Special">&lt;-</span> start-reading resources, filename
+  <span class="muControl">return-if</span> error?, <span class="Constant">0/contents</span>
+  buf:&amp;:buffer <span class="Special">&lt;-</span> new-buffer <span class="Constant">30/capacity</span>
+  <span class="Delimiter">{</span>
+    c:char, done?:bool, source <span class="Special">&lt;-</span> read source
+    <span class="muControl">break-if</span> done?
+    buf <span class="Special">&lt;-</span> append buf, c
+    <span class="muControl">loop</span>
+  <span class="Delimiter">}</span>
+  contents <span class="Special">&lt;-</span> buffer-to-array buf
+]
+
+<span class="muRecipe">def</span> start-reading-from-fake-resource resources:&amp;:resources, resource:text<span class="muRecipe"> -&gt; </span>contents:&amp;:source:char, error?:bool [
+  <span class="Constant">local-scope</span>
+  <span class="Constant">load-ingredients</span>
+  error? <span class="Special">&lt;-</span> copy <span class="Constant">0/no-error</span>
   i:num <span class="Special">&lt;-</span> copy<span class="Constant"> 0</span>
   data:&amp;:@:resource <span class="Special">&lt;-</span> get *resources, <span class="Constant">data:offset</span>
   len:num <span class="Special">&lt;-</span> length *data
@@ -79,7 +103,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     start-running receive-from-text curr-contents, sink
     <span class="muControl">return</span>
   <span class="Delimiter">}</span>
-  <span class="muControl">return</span> <span class="Constant">0/not-found</span>
+  <span class="muControl">return</span> <span class="Constant">0/not-found</span>, <span class="Constant">1/error</span>
 ]
 
 <span class="muRecipe">def</span> receive-from-file file:num, sink:&amp;:sink:char<span class="muRecipe"> -&gt; </span>sink:&amp;:sink:char [
@@ -111,18 +135,20 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   sink <span class="Special">&lt;-</span> close sink
 ]
 
-<span class="muRecipe">def</span> start-writing resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>sink:&amp;:sink:char, routine-id:num [
+<span class="muRecipe">def</span> start-writing resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>sink:&amp;:sink:char, routine-id:num, error?:bool [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
+  error? <span class="Special">&lt;-</span> copy <span class="Constant">0/false</span>
   source:&amp;:source:char, sink:&amp;:sink:char <span class="Special">&lt;-</span> new-channel<span class="Constant"> 30</span>
   <span class="Delimiter">{</span>
     <span class="muControl">break-unless</span> resources
     <span class="Comment"># fake file system</span>
-    routine-id <span class="Special">&lt;-</span> start-running transmit-to-fake-file resources, filename, source
+    routine-id <span class="Special">&lt;-</span> start-running transmit-to-fake-resource resources, filename, source
     <span class="muControl">return</span>
   <span class="Delimiter">}</span>
   <span class="Comment"># real file system</span>
   file:num <span class="Special">&lt;-</span> $open-file-for-writing filename
+  <span class="muControl">return-unless</span> file, <span class="Constant">0/sink</span>, <span class="Constant">0/routine-id</span>, <span class="Constant">1/error?</span>
   <span class="Delimiter">{</span>
     <span class="muControl">break-if</span> file
     msg:text <span class="Special">&lt;-</span> append <span class="Constant">[no such file: ]</span> filename
@@ -131,6 +157,29 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   routine-id <span class="Special">&lt;-</span> start-running transmit-to-file file, source
 ]
 
+<span class="muRecipe">def</span> dump resources:&amp;:resources, filename:text, contents:text<span class="muRecipe"> -&gt; </span>resources:&amp;:resources, error?:bool [
+  <span class="Constant">local-scope</span>
+  <span class="Constant">load-ingredients</span>
+  <span class="Comment"># todo: really create an empty file</span>
+  <span class="muControl">return-unless</span> contents, resources, <span class="Constant">0/no-error</span>
+  sink-file:&amp;:sink:char, write-routine:num, error?:bool <span class="Special">&lt;-</span> start-writing resources, filename
+  <span class="muControl">return-if</span> error?
+  i:num <span class="Special">&lt;-</span> copy<span class="Constant"> 0</span>
+  len:num <span class="Special">&lt;-</span> length *contents
+  <span class="Delimiter">{</span>
+    done?:bool <span class="Special">&lt;-</span> greater-or-equal i, len
+    <span class="muControl">break-if</span> done?
+    c:char <span class="Special">&lt;-</span> index *contents, i
+    sink-file <span class="Special">&lt;-</span> write sink-file, c
+    i <span class="Special">&lt;-</span> add i,<span class="Constant"> 1</span>
+    <span class="muControl">loop</span>
+  <span class="Delimiter">}</span>
+  close sink-file
+  <span class="Comment"># make sure to wait for the file to be actually written to disk</span>
+  <span class="Comment"># (Mu practices structured concurrency: <a href="http://250bpm.com/blog:71)">http://250bpm.com/blog:71)</a></span>
+  wait-for-routine write-routine
+]
+
 <span class="muRecipe">def</span> transmit-to-file file:num, source:&amp;:source:char<span class="muRecipe"> -&gt; </span>source:&amp;:source:char [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
@@ -143,7 +192,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   file <span class="Special">&lt;-</span> $close-file file
 ]
 
-<span class="muRecipe">def</span> transmit-to-fake-file resources:&amp;:resources, filename:text, source:&amp;:source:char<span class="muRecipe"> -&gt; </span>resources:&amp;:resources, source:&amp;:source:char [
+<span class="muRecipe">def</span> transmit-to-fake-resource resources:&amp;:resources, filename:text, source:&amp;:source:char<span class="muRecipe"> -&gt; </span>resources:&amp;:resources, source:&amp;:source:char [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   lock:location <span class="Special">&lt;-</span> get-location *resources, <span class="Constant">lock:offset</span>
diff --git a/html/090scenario_filesystem_test.mu.html b/html/090scenario_filesystem_test.mu.html
index 91d039bb..20aad6a6 100644
--- a/html/090scenario_filesystem_test.mu.html
+++ b/html/090scenario_filesystem_test.mu.html
@@ -13,12 +13,9 @@
 pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
 body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; }
 * { font-size: 12pt; font-size: 1em; }
-.Delimiter { color: #800080; }
-.muControl { color: #c0a020; }
 .Comment { color: #9090ff; }
 .Constant { color: #00a0a0; }
 .Special { color: #c00000; }
-.muRecipe { color: #ff8700; }
 .muScenario { color: #00af00; }
 -->
 </style>
@@ -130,20 +127,6 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
    <span class="Constant"> 11</span> <span class="Special">&lt;-</span><span class="Constant"> 1</span>  <span class="Comment"># other files also continue to persist unchanged</span>
   ]
 ]
-
-<span class="muRecipe">def</span> slurp resources:&amp;:resources, filename:text<span class="muRecipe"> -&gt; </span>contents:text [
-  <span class="Constant">local-scope</span>
-  <span class="Constant">load-ingredients</span>
-  source:&amp;:source:char <span class="Special">&lt;-</span> start-reading resources, filename
-  buf:&amp;:buffer <span class="Special">&lt;-</span> new-buffer <span class="Constant">30/capacity</span>
-  <span class="Delimiter">{</span>
-    c:char, done?:bool, source <span class="Special">&lt;-</span> read source
-    <span class="muControl">break-if</span> done?
-    buf <span class="Special">&lt;-</span> append buf, c
-    <span class="muControl">loop</span>
-  <span class="Delimiter">}</span>
-  contents <span class="Special">&lt;-</span> buffer-to-array buf
-]
 </pre>
 </body>
 </html>
diff --git a/html/092socket.mu.html b/html/092socket.mu.html
index f33fb8bd..cbff28cc 100644
--- a/html/092socket.mu.html
+++ b/html/092socket.mu.html
@@ -111,7 +111,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Delimiter">{</span>
     <span class="muControl">break-unless</span> resources
     <span class="Comment"># fake network</span>
-    contents <span class="Special">&lt;-</span> start-reading-from-fake-resources resources, uri
+    contents <span class="Special">&lt;-</span> start-reading-from-fake-resource resources, uri
     <span class="muControl">return</span>
   <span class="Delimiter">}</span>
   <span class="Comment"># real network</span>
diff --git a/html/101run_sandboxed.cc.html b/html/101run_sandboxed.cc.html
index 7b5da51b..0090e189 100644
--- a/html/101run_sandboxed.cc.html
+++ b/html/101run_sandboxed.cc.html
@@ -463,8 +463,8 @@ string strip_comments<span class="Delimiter">(</span>string in<span class="Delim
     <span class="Normal">if</span> <span class="Delimiter">(</span>*--p<span class="Delimiter">-&gt;</span>contents<span class="Delimiter">.</span>end<span class="Delimiter">()</span> != <span class="cSpecial">'\n'</span><span class="Delimiter">)</span> out &lt;&lt; <span class="cSpecial">'\n'</span><span class="Delimiter">;</span>
   <span class="Delimiter">}</span>
   string result = out<span class="Delimiter">.</span>str<span class="Delimiter">();</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>result<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Identifier">return</span> <span class="Constant">0</span><span class="Delimiter">;</span>
   truncate<span class="Delimiter">(</span>result<span class="Delimiter">);</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>result<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Identifier">return</span> <span class="Constant">0</span><span class="Delimiter">;</span>
   <span class="Identifier">return</span> new_mu_text<span class="Delimiter">(</span>result<span class="Delimiter">);</span>
 <span class="Delimiter">}</span>
 
diff --git a/html/102persist.cc.html b/html/102persist.cc.html
deleted file mode 100644
index 863546d2..00000000
--- a/html/102persist.cc.html
+++ /dev/null
@@ -1,154 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
-<html>
-<head>
-<meta http-equiv="content-type" content="text/html; charset=UTF-8">
-<title>Mu - 102persist.cc</title>
-<meta name="Generator" content="Vim/7.4">
-<meta name="plugin-version" content="vim7.4_v2">
-<meta name="syntax" content="cpp">
-<meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy=">
-<meta name="colorscheme" content="minimal">
-<style type="text/css">
-<!--
-pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
-body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; }
-* { font-size: 12pt; font-size: 1em; }
-.Constant { color: #00a0a0; }
-.Comment { color: #9090ff; }
-.Delimiter { color: #800080; }
-.cSpecial { color: #008000; }
-.Identifier { color: #c0a020; }
-.Normal { color: #eeeeee; background-color: #080808; padding-bottom: 1px; }
--->
-</style>
-
-<script type='text/javascript'>
-<!--
-
--->
-</script>
-</head>
-<body>
-<pre id='vimCodeElement'>
-<span class="Comment">//: Dead simple persistence.</span>
-<span class="Comment">//:   'restore' - reads string from a file</span>
-<span class="Comment">//:   'save' - writes string to a file</span>
-
-<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
-RESTORE<span class="Delimiter">,</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Numbers&quot;)</span>
-put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;restore&quot;</span><span class="Delimiter">,</span> RESTORE<span class="Delimiter">);</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
-<span class="Normal">case</span> RESTORE: <span class="Delimiter">{</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">)</span> != <span class="Constant">1</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
-    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;'restore' requires exactly one ingredient, but got '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  string filename<span class="Delimiter">;</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>is_literal_text<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    <span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_text<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    <span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Delimiter">{</span>
-    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;first ingredient of 'restore' should be a string, but got '&quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">))</span> &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span class="Delimiter">}</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Implementations&quot;)</span>
-<span class="Normal">case</span> RESTORE: <span class="Delimiter">{</span>
-  string filename<span class="Delimiter">;</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>is_literal_text<span class="Delimiter">(</span>current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    filename = current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>name<span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_text<span class="Delimiter">(</span>current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    filename = read_mu_text<span class="Delimiter">(</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">));</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>Current_scenario<span class="Delimiter">)</span> <span class="Delimiter">{</span>
-    <span class="Comment">// do nothing in tests</span>
-    products<span class="Delimiter">.</span>resize<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span>
-    products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>push_back<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  string contents = slurp<span class="Delimiter">(</span><span class="Constant">&quot;lesson/&quot;</span>+filename<span class="Delimiter">);</span>
-  products<span class="Delimiter">.</span>resize<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">);</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>contents<span class="Delimiter">.</span>empty<span class="Delimiter">())</span>
-    products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>push_back<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
-  <span class="Normal">else</span>
-    products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>push_back<span class="Delimiter">(</span>new_mu_text<span class="Delimiter">(</span>contents<span class="Delimiter">));</span>
-  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span class="Delimiter">}</span>
-
-<span class="Delimiter">:(code)</span>
-<span class="Comment">// <a href="http://cpp.indi.frih.net/blog/2014/09/how-to-read-an-entire-file-into-memory-in-cpp">http://cpp.indi.frih.net/blog/2014/09/how-to-read-an-entire-file-into-memory-in-cpp</a></span>
-string slurp<span class="Delimiter">(</span><span class="Normal">const</span> string&amp; filename<span class="Delimiter">)</span> <span class="Delimiter">{</span>
-  ifstream fin<span class="Delimiter">(</span>filename<span class="Delimiter">.</span>c_str<span class="Delimiter">());</span>
-  fin<span class="Delimiter">.</span>peek<span class="Delimiter">();</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>!fin<span class="Delimiter">)</span> <span class="Identifier">return</span> <span class="Constant">&quot;&quot;</span><span class="Delimiter">;</span>  <span class="Comment">// don't bother checking errno</span>
-  ostringstream result<span class="Delimiter">;</span>
-  result &lt;&lt; fin<span class="Delimiter">.</span>rdbuf<span class="Delimiter">();</span>
-  fin<span class="Delimiter">.</span>close<span class="Delimiter">();</span>
-  <span class="Identifier">return</span> result<span class="Delimiter">.</span>str<span class="Delimiter">();</span>
-<span class="Delimiter">}</span>
-
-<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
-SAVE<span class="Delimiter">,</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Numbers&quot;)</span>
-put<span class="Delimiter">(</span>Recipe_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;save&quot;</span><span class="Delimiter">,</span> SAVE<span class="Delimiter">);</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
-<span class="Normal">case</span> SAVE: <span class="Delimiter">{</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>SIZE<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">)</span> != <span class="Constant">2</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
-    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;'save' requires exactly two ingredients, but got '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>is_literal_text<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    <span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_text<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    <span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Delimiter">{</span>
-    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;first ingredient of 'save' should be a string, but got '&quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">))</span> &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_text<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    raise &lt;&lt; maybe<span class="Delimiter">(</span>get<span class="Delimiter">(</span>Recipe<span class="Delimiter">,</span> r<span class="Delimiter">).</span>name<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;second ingredient of 'save' should be an address:@:char, but got '&quot;</span> &lt;&lt; to_string<span class="Delimiter">(</span>inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">))</span> &lt;&lt; <span class="Constant">&quot;'</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
-    <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span class="Delimiter">}</span>
-<span class="Delimiter">:(before &quot;End Primitive Recipe Implementations&quot;)</span>
-<span class="Normal">case</span> SAVE: <span class="Delimiter">{</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>Current_scenario<span class="Delimiter">)</span> <span class="Identifier">break</span><span class="Delimiter">;</span>  <span class="Comment">// do nothing in tests</span>
-  string filename<span class="Delimiter">;</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>is_literal_text<span class="Delimiter">(</span>current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    filename = current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>name<span class="Delimiter">;</span>
-  <span class="Delimiter">}</span>
-  <span class="Normal">else</span> <span class="Normal">if</span> <span class="Delimiter">(</span>is_mu_text<span class="Delimiter">(</span>current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)))</span> <span class="Delimiter">{</span>
-    filename = read_mu_text<span class="Delimiter">(</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">));</span>
-  <span class="Delimiter">}</span>
-  ofstream fout<span class="Delimiter">((</span><span class="Constant">&quot;lesson/&quot;</span>+filename<span class="Delimiter">).</span>c_str<span class="Delimiter">());</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>!fout<span class="Delimiter">)</span> <span class="Identifier">break</span><span class="Delimiter">;</span>
-  string contents = read_mu_text<span class="Delimiter">(</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">).</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">));</span>
-  fout &lt;&lt; contents<span class="Delimiter">;</span>
-  fout<span class="Delimiter">.</span>close<span class="Delimiter">();</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>!exists<span class="Delimiter">(</span><span class="Constant">&quot;lesson/.git&quot;</span><span class="Delimiter">))</span> <span class="Identifier">break</span><span class="Delimiter">;</span>
-  <span class="Comment">// bug in git: git diff -q messes up --exit-code</span>
-  <span class="Comment">// explicitly say '--all' for git 1.9</span>
-  <span class="Normal">int</span> status = system<span class="Delimiter">(</span><span class="Constant">&quot;cd lesson; git add --all .; git diff HEAD --exit-code &gt;/dev/null || git commit -a -m . &gt;/dev/null&quot;</span><span class="Delimiter">);</span>
-  <span class="Normal">if</span> <span class="Delimiter">(</span>status != <span class="Constant">0</span><span class="Delimiter">)</span>
-    raise &lt;&lt; <span class="Constant">&quot;error in commit: contents &quot;</span> &lt;&lt; contents &lt;&lt; <span class="cSpecial">'\n'</span> &lt;&lt; end<span class="Delimiter">();</span>
-  <span class="Identifier">break</span><span class="Delimiter">;</span>
-<span class="Delimiter">}</span>
-
-<span class="Delimiter">:(code)</span>
-<span class="Normal">bool</span> exists<span class="Delimiter">(</span><span class="Normal">const</span> string&amp; filename<span class="Delimiter">)</span> <span class="Delimiter">{</span>
-  <span class="Normal">struct</span> stat dummy<span class="Delimiter">;</span>
-  <span class="Identifier">return</span> <span class="Constant">0</span> == stat<span class="Delimiter">(</span>filename<span class="Delimiter">.</span>c_str<span class="Delimiter">(),</span> &amp;dummy<span class="Delimiter">);</span>
-<span class="Delimiter">}</span>
-</pre>
-</body>
-</html>
-<!-- vim: set foldmethod=manual : -->
diff --git a/html/edit/004-programming-environment.mu.html b/html/edit/004-programming-environment.mu.html
index 776c336e..9cbe6f6f 100644
--- a/html/edit/004-programming-environment.mu.html
+++ b/html/edit/004-programming-environment.mu.html
@@ -41,12 +41,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <span class="muRecipe">def!</span> main [
   <span class="Constant">local-scope</span>
   open-console
-  initial-recipe:text <span class="Special">&lt;-</span> restore <span class="Constant">[recipes.mu]</span>
-  initial-sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[]</span>
-  hide-screen <span class="Constant">0/screen</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment <span class="Constant">0/screen</span>, initial-recipe, initial-sandbox
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment <span class="Constant">0/filesystem</span>, <span class="Constant">0/screen</span>
   render-all <span class="Constant">0/screen</span>, env, render
-  event-loop <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>, env
+  event-loop <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>, env, <span class="Constant">0/filesystem</span>
   <span class="Comment"># never gets here</span>
 ]
 
@@ -56,24 +53,25 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   sandbox-in-focus?:bool  <span class="Comment"># false =&gt; cursor in recipes; true =&gt; cursor in current-sandbox</span>
 ]
 
-<span class="muRecipe">def</span> new-programming-environment screen:&amp;:screen, initial-recipe-contents:text, initial-sandbox-contents:text<span class="muRecipe"> -&gt; </span>result:&amp;:environment [
+<span class="muRecipe">def</span> new-programming-environment resources:&amp;:resources, screen:&amp;:screen, test-sandbox-editor-contents:text<span class="muRecipe"> -&gt; </span>result:&amp;:environment [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   width:num <span class="Special">&lt;-</span> screen-width screen
   result <span class="Special">&lt;-</span> new <span class="Constant">environment:type</span>
   <span class="Comment"># recipe editor on the left</span>
+  initial-recipe-contents:text <span class="Special">&lt;-</span> slurp resources, <span class="Constant">[lesson/recipes.mu]</span>  <span class="Comment"># ignore errors</span>
   divider:num, _ <span class="Special">&lt;-</span> divide-with-remainder width,<span class="Constant"> 2</span>
   recipes:&amp;:editor <span class="Special">&lt;-</span> new-editor initial-recipe-contents, <span class="Constant">0/left</span>, divider/right
   <span class="Comment"># sandbox editor on the right</span>
   sandbox-left:num <span class="Special">&lt;-</span> add divider,<span class="Constant"> 1</span>
-  current-sandbox:&amp;:editor <span class="Special">&lt;-</span> new-editor initial-sandbox-contents, sandbox-left, width/right
+  current-sandbox:&amp;:editor <span class="Special">&lt;-</span> new-editor test-sandbox-editor-contents, sandbox-left, width/right
   *result <span class="Special">&lt;-</span> put *result, <span class="Constant">recipes:offset</span>, recipes
   *result <span class="Special">&lt;-</span> put *result, <span class="Constant">current-sandbox:offset</span>, current-sandbox
   *result <span class="Special">&lt;-</span> put *result, <span class="Constant">sandbox-in-focus?:offset</span>, <span class="Constant">0/false</span>
 <span class="Constant">  &lt;programming-environment-initialization&gt;</span>
 ]
 
-<span class="muRecipe">def</span> event-loop screen:&amp;:screen, console:&amp;:console, env:&amp;:environment<span class="muRecipe"> -&gt; </span>screen:&amp;:screen, console:&amp;:console, env:&amp;:environment [
+<span class="muRecipe">def</span> event-loop screen:&amp;:screen, console:&amp;:console, env:&amp;:environment, resources:&amp;:resources<span class="muRecipe"> -&gt; </span>screen:&amp;:screen, console:&amp;:console, env:&amp;:environment, resources:&amp;:resources [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   recipes:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">recipes:offset</span>
@@ -321,7 +319,12 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">30/width</span>, <span class="Constant">5/height</span>
   <span class="Comment"># initialize both halves of screen</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[abc]</span>, <span class="Constant">[def]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+<span class="Constant">      |abc|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[def]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># focus on both sides</span>
   assume-console [
     left-click<span class="Constant"> 1</span>,<span class="Constant"> 1</span>
@@ -329,7 +332,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   ]
   <span class="Comment"># check cursor column in each</span>
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     recipes:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">recipes:offset</span>
     5:num/<span class="Special">raw</span> <span class="Special">&lt;-</span> get *recipes, <span class="Constant">cursor-column:offset</span>
     sandbox:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">current-sandbox:offset</span>
@@ -346,7 +349,12 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">30/width</span>, <span class="Constant">5/height</span>
   <span class="Comment"># initialize both halves of screen</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[abc]</span>, <span class="Constant">[def]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+<span class="Constant">      |abc|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[def]</span>  <span class="Comment"># contents of sandbox</span>
   render-all screen, env, render
   <span class="Comment"># type one letter in each of them</span>
   assume-console [
@@ -356,7 +364,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[1]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     recipes:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">recipes:offset</span>
     5:num/<span class="Special">raw</span> <span class="Special">&lt;-</span> get *recipes, <span class="Constant">cursor-column:offset</span>
     sandbox:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">current-sandbox:offset</span>
@@ -365,7 +373,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   screen-should-contain [
    <span class="Constant"> .           run (F4)           .  # this line has a different background, but we don't test that yet</span>
    <span class="Constant"> .a0bc           ╎d1ef          .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎──────────────.</span>
+   <span class="Constant"> .               ╎──────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .</span>
    <span class="Constant"> .               ╎              .</span>
   ]
   memory-should-contain [
@@ -380,39 +389,27 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   screen-should-contain [
    <span class="Constant"> .           run (F4)           .</span>
    <span class="Constant"> .a0bc           ╎d1␣f          .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎──────────────.</span>
+   <span class="Constant"> .               ╎──────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .</span>
    <span class="Constant"> .               ╎              .</span>
   ]
 ]
 
-<span class="muScenario">scenario</span> multiple-editors-cover-only-their-own-areas [
-  <span class="Constant">local-scope</span>
-  trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
-  assume-screen <span class="Constant">60/width</span>, <span class="Constant">10/height</span>
-  run [
-    env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[abc]</span>, <span class="Constant">[def]</span>
-    render-all screen, env, render
-  ]
-  <span class="Comment"># divider isn't messed up</span>
-  screen-should-contain [
-   <span class="Constant"> .                                         run (F4)           .</span>
-   <span class="Constant"> .abc                           ╎def                          .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────.</span>
-   <span class="Constant"> .                              ╎                             .</span>
-   <span class="Constant"> .                              ╎                             .</span>
-  ]
-]
-
 <span class="muScenario">scenario</span> editor-in-focus-keeps-cursor [
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">30/width</span>, <span class="Constant">5/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[abc]</span>, <span class="Constant">[def]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+<span class="Constant">      |abc|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[def]</span>
   render-all screen, env, render
   <span class="Comment"># initialize programming environment and highlight cursor</span>
   assume-console <span class="Constant">[]</span>
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -420,7 +417,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   screen-should-contain [
    <span class="Constant"> .           run (F4)           .</span>
    <span class="Constant"> .␣bc            ╎def           .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎──────────────.</span>
+   <span class="Constant"> .               ╎──────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .</span>
    <span class="Constant"> .               ╎              .</span>
   ]
   <span class="Comment"># now try typing a letter</span>
@@ -428,7 +426,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[z]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -436,7 +434,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   screen-should-contain [
    <span class="Constant"> .           run (F4)           .</span>
    <span class="Constant"> .z␣bc           ╎def           .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎──────────────.</span>
+   <span class="Constant"> .               ╎──────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎              .</span>
    <span class="Constant"> .               ╎              .</span>
   ]
 ]
@@ -445,10 +444,12 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">30/width</span>, <span class="Constant">5/height</span>
+  assume-resources [
+  ]
   <span class="Comment"># initialize sandbox side with two lines</span>
-  s:text <span class="Special">&lt;-</span> new <span class="Constant">[abc</span>
+  test-sandbox-editor-contents:text <span class="Special">&lt;-</span> new <span class="Constant">[abc</span>
 <span class="Constant">def]</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, s:text
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, test-sandbox-editor-contents
   render-all screen, env, render
   screen-should-contain [
    <span class="Constant"> .           run (F4)           .</span>
@@ -463,7 +464,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press backspace
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
diff --git a/html/edit/005-sandbox.mu.html b/html/edit/005-sandbox.mu.html
index b7afa986..095fa72d 100644
--- a/html/edit/005-sandbox.mu.html
+++ b/html/edit/005-sandbox.mu.html
@@ -45,13 +45,10 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <span class="muRecipe">def!</span> main [
   <span class="Constant">local-scope</span>
   open-console
-  initial-recipe:text <span class="Special">&lt;-</span> restore <span class="Constant">[recipes.mu]</span>
-  initial-sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[]</span>
-  hide-screen <span class="Constant">0/screen</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment <span class="Constant">0/screen</span>, initial-recipe, initial-sandbox
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment <span class="Constant">0/filesystem</span>, <span class="Constant">0/screen</span>
   env <span class="Special">&lt;-</span> restore-sandboxes env
   render-all <span class="Constant">0/screen</span>, env, render
-  event-loop <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>, env
+  event-loop <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>, env, <span class="Constant">0/filesystem</span>
   <span class="Comment"># never gets here</span>
 ]
 
@@ -81,14 +78,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
   <span class="Comment"># recipe editor is empty</span>
+  assume-resources [
+  ]
   <span class="Comment"># sandbox editor contains an instruction without storing outputs</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[divide-with-remainder 11, 3]</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[divide-with-remainder 11, 3]</span>
   <span class="Comment"># run the code in the editors</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that screen prints the results</span>
   screen-should-contain [
@@ -138,7 +137,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that screen prints both sandboxes</span>
   screen-should-contain [
@@ -164,7 +163,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     do-run?:bool <span class="Special">&lt;-</span> equal k, <span class="Constant">65532/F4</span>
     <span class="muControl">break-unless</span> do-run?
     screen <span class="Special">&lt;-</span> update-status screen, <span class="Constant">[running...       ]</span>, <span class="Constant">245/grey</span>
-    error?:bool, env, screen <span class="Special">&lt;-</span> run-sandboxes env, screen
+    error?:bool <span class="Special">&lt;-</span> run-sandboxes env, resources, screen
     <span class="Comment"># F4 might update warnings and results on both sides</span>
     screen <span class="Special">&lt;-</span> render-all screen, env, render
     <span class="Delimiter">{</span>
@@ -176,10 +175,10 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Delimiter">}</span>
 ]
 
-<span class="muRecipe">def</span> run-sandboxes env:&amp;:environment, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, screen:&amp;:screen [
+<span class="muRecipe">def</span> run-sandboxes env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
-  errors-found?:bool, env, screen <span class="Special">&lt;-</span> update-recipes env, screen
+  errors-found?:bool <span class="Special">&lt;-</span> update-recipes env, resources, screen
   <span class="muControl">return-if</span> errors-found?
   <span class="Comment"># check contents of right editor (sandbox)</span>
 <span class="Constant">  &lt;run-sandboxes-begin&gt;</span>
@@ -205,7 +204,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     *current-sandbox <span class="Special">&lt;-</span> put *current-sandbox, <span class="Constant">top-of-screen:offset</span>, init
   <span class="Delimiter">}</span>
   <span class="Comment"># save all sandboxes before running, just in case we die when running</span>
-  save-sandboxes env
+  save-sandboxes env, resources
   <span class="Comment"># run all sandboxes</span>
   curr:&amp;:sandbox <span class="Special">&lt;-</span> get *env, <span class="Constant">sandbox:offset</span>
   idx:num <span class="Special">&lt;-</span> copy<span class="Constant"> 0</span>
@@ -219,14 +218,14 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <span class="Constant">  &lt;run-sandboxes-end&gt;</span>
 ]
 
-<span class="Comment"># copy code from recipe editor, persist to disk, load</span>
+<span class="Comment"># load code from disk</span>
 <span class="Comment"># replaced in a later layer (whereupon errors-found? will actually be set)</span>
-<span class="muRecipe">def</span> update-recipes env:&amp;:environment, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, screen:&amp;:screen [
+<span class="muRecipe">def</span> update-recipes env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   recipes:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">recipes:offset</span>
   in:text <span class="Special">&lt;-</span> editor-contents recipes
-  save <span class="Constant">[recipes.mu]</span>, in  <span class="Comment"># newlayer: persistence</span>
+  resources <span class="Special">&lt;-</span> dump resources, <span class="Constant">[lesson/recipes.mu]</span>, in
   reload in
   errors-found? <span class="Special">&lt;-</span> copy <span class="Constant">0/false</span>
 ]
@@ -248,7 +247,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   screen <span class="Special">&lt;-</span> print screen, msg, color, <span class="Constant">238/grey/background</span>
 ]
 
-<span class="muRecipe">def</span> save-sandboxes env:&amp;:environment [
+<span class="muRecipe">def</span> save-sandboxes env:&amp;:environment, resources:&amp;:resources<span class="muRecipe"> -&gt; </span>resources:&amp;:resources [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   current-sandbox:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">current-sandbox:offset</span>
@@ -259,8 +258,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Delimiter">{</span>
     <span class="muControl">break-unless</span> curr
     data:text <span class="Special">&lt;-</span> get *curr, <span class="Constant">data:offset</span>
-    filename:text <span class="Special">&lt;-</span> to-text idx
-    save filename, data
+    filename:text <span class="Special">&lt;-</span> append <span class="Constant">[lesson/]</span>, idx
+    resources <span class="Special">&lt;-</span> dump resources, filename, data
 <span class="Constant">    &lt;end-save-sandbox&gt;</span>
     idx <span class="Special">&lt;-</span> add idx,<span class="Constant"> 1</span>
     curr <span class="Special">&lt;-</span> get *curr, <span class="Constant">next-sandbox:offset</span>
@@ -450,7 +449,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 ]
 
 <span class="Comment"># assumes programming environment has no sandboxes; restores them from previous session</span>
-<span class="muRecipe">def</span> restore-sandboxes env:&amp;:environment<span class="muRecipe"> -&gt; </span>env:&amp;:environment [
+<span class="muRecipe">def</span> restore-sandboxes env:&amp;:environment, resources:&amp;:resources<span class="muRecipe"> -&gt; </span>env:&amp;:environment [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   <span class="Comment"># read all scenarios, pushing them to end of a list of scenarios</span>
@@ -458,8 +457,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   curr:&amp;:sandbox <span class="Special">&lt;-</span> copy<span class="Constant"> 0</span>
   prev:&amp;:sandbox <span class="Special">&lt;-</span> copy<span class="Constant"> 0</span>
   <span class="Delimiter">{</span>
-    filename:text <span class="Special">&lt;-</span> to-text idx
-    contents:text <span class="Special">&lt;-</span> restore filename
+    filename:text <span class="Special">&lt;-</span> append <span class="Constant">[lesson/]</span>, idx
+    contents:text <span class="Special">&lt;-</span> slurp resources, filename
     <span class="muControl">break-unless</span> contents  <span class="Comment"># stop at first error; assuming file didn't exist</span>
                            <span class="Comment"># todo: handle empty sandbox</span>
     <span class="Comment"># create new sandbox for file</span>
@@ -554,27 +553,32 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">12/height</span>
   <span class="Comment"># define a recipe (no indent for the 'add' line below so column numbers are more obvious)</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">local-scope</span>
-<span class="Constant">z:num &lt;- add 2, 2</span>
-<span class="Constant">reply z</span>
-<span class="Constant">]</span>]
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+<span class="Constant">      ||</span>
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  z:num &lt;- add 2, 2|</span>
+<span class="Constant">      |  reply z|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
   <span class="Comment"># sandbox editor contains an instruction without storing outputs</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># run the code in the editors</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .local-scope                                       ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .z:num &lt;- add 2, 2                                 ╎foo                                              .</span>
-   <span class="Constant"> .reply z                                           ╎4                                                .</span>
+   <span class="Constant"> .  local-scope                                     ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  z:num &lt;- add 2, 2                               ╎foo                                              .</span>
+   <span class="Constant"> .  reply z                                         ╎4                                                .</span>
    <span class="Constant"> .]                                                 ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -586,17 +590,18 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that screen updates the result on the right</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .local-scope                                       ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .z:num &lt;- add 2, 3                                 ╎foo                                              .</span>
-   <span class="Constant"> .reply z                                           ╎5                                                .</span>
+   <span class="Constant"> .  local-scope                                     ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  z:num &lt;- add 2, 3                               ╎foo                                              .</span>
+   <span class="Constant"> .  reply z                                         ╎5                                                .</span>
    <span class="Constant"> .]                                                 ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -606,15 +611,17 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">20/height</span>
-  <span class="Comment"># left editor is empty</span>
-  <span class="Comment"># right editor contains an instruction</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[print-integer screen, 4]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  <span class="Comment"># sandbox editor contains an instruction</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[print-integer screen, 4]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># run the code in the editor</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that it prints a little toy screen</span>
   screen-should-contain [
@@ -677,13 +684,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   assume-console [
     press enter
     press down-arrow
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   <span class="Comment"># no scroll</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
@@ -698,14 +707,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   assume-console [
     press enter
     press up-arrow
     press down-arrow  <span class="Comment"># while cursor isn't at bottom</span>
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
   print screen, cursor
   <span class="Comment"># cursor moves back to bottom</span>
@@ -776,7 +787,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   assume-console [
     <span class="Comment"># add a line</span>
@@ -786,7 +799,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     <span class="Comment"># try to scroll</span>
     press page-down  <span class="Comment"># or ctrl-f</span>
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   <span class="Comment"># no scroll, and cursor remains at top line</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
@@ -801,7 +814,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[ab</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[ab</span>
 <span class="Constant">cd]</span>
   render-all screen, env, render
   assume-console [
@@ -812,7 +827,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     <span class="Comment"># move cursor</span>
     press down-arrow
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
   print screen, cursor
   <span class="Comment"># no scroll on recipe side, cursor moves on sandbox side</span>
@@ -831,14 +846,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># initialize sandbox side</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[add 2, 2]</span>
+  <span class="Comment"># initialize</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 2, 2]</span>
   render-all screen, env, render
   assume-console [
     <span class="Comment"># create a sandbox</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -852,7 +869,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -870,7 +887,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-up
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -959,30 +976,33 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="muControl">return</span> curr
 ]
 
-<span class="muScenario">scenario</span> scrolling-down-on-recipe-side [
+<span class="muScenario">scenario</span> scrolling-down-past-bottom-on-recipe-side [
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize sandbox side and create a sandbox</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">||</span>  <span class="Comment"># file containing just a newline</span>
+    ]
+  ]
   <span class="Comment"># create a sandbox</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes:text, <span class="Constant">[add 2, 2]</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 2, 2]</span>
   render-all screen, env, render
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   <span class="Comment"># hit 'down' in recipe editor</span>
   assume-console [
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
-  <span class="Comment"># cursor moves down on recipe side</span>
+  <span class="Comment"># cursor doesn't move when the end is already on-screen</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .␣                                                 ╎                                                 .</span>
@@ -997,7 +1017,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes</span>
   assume-console [
@@ -1007,7 +1029,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[add 1, 1]</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
   print screen, cursor
   screen-should-contain [
@@ -1027,7 +1049,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -1049,7 +1071,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># just second sandbox displayed</span>
   screen-should-contain [
@@ -1066,7 +1088,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># no change</span>
   screen-should-contain [
@@ -1083,7 +1105,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-up
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># back to displaying both sandboxes without editor</span>
   screen-should-contain [
@@ -1102,7 +1124,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-up
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -1124,7 +1146,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-up
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
@@ -1148,7 +1170,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create a sandbox</span>
   assume-console [
@@ -1156,7 +1180,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[add 1, 1]</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -1172,7 +1196,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># sandbox editor hidden; first sandbox displayed</span>
   <span class="Comment"># cursor moves to first sandbox</span>
@@ -1190,7 +1214,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-up
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># back to displaying both sandboxes as well as editor</span>
   screen-should-contain [
@@ -1208,7 +1232,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># sandbox editor hidden; first sandbox displayed</span>
   <span class="Comment"># cursor moves to first sandbox</span>
diff --git a/html/edit/006-sandbox-copy.mu.html b/html/edit/006-sandbox-copy.mu.html
index 3459f1f2..b6e9f280 100644
--- a/html/edit/006-sandbox-copy.mu.html
+++ b/html/edit/006-sandbox-copy.mu.html
@@ -39,24 +39,22 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 1, 1]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -65,16 +63,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 69</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># it copies into editor</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -83,15 +81,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[0]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎0foo                                             .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+   <span class="Constant"> .                                                  ╎0add 1, 1                                        .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -101,24 +99,22 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 1, 1]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -127,16 +123,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 84</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># it copies into editor</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -145,15 +141,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[0]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎0foo                                             .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+   <span class="Constant"> .                                                  ╎0add 1, 1                                        .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -258,24 +254,22 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 1, 1]</span>  <span class="Comment"># contents of sandbox editor</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -286,16 +280,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 70</span>  <span class="Comment"># click 'copy' button</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># copy doesn't happen</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎0                                                .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -304,15 +298,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[1]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎01                                               .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 1, 1                                         .</span>
+   <span class="Constant"> .                                                  ╎2                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
diff --git a/html/edit/007-sandbox-delete.mu.html b/html/edit/007-sandbox-delete.mu.html
index 48028d51..06dd8fc5 100644
--- a/html/edit/007-sandbox-delete.mu.html
+++ b/html/edit/007-sandbox-delete.mu.html
@@ -38,7 +38,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   <span class="Comment"># run a few commands</span>
   assume-console [
     left-click<span class="Constant"> 1</span>,<span class="Constant"> 80</span>
@@ -47,7 +49,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[add 2, 2]</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -68,7 +70,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 7</span>,<span class="Constant"> 85</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
@@ -86,7 +88,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 99</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
@@ -185,7 +187,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes and scroll to second</span>
   assume-console [
@@ -196,7 +200,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
     press page-down
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
@@ -211,7 +215,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 6</span>,<span class="Constant"> 99</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># second sandbox shows in editor; scroll resets to display first sandbox</span>
   screen-should-contain [
@@ -230,7 +234,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes and scroll to second</span>
   assume-console [
@@ -241,7 +247,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
     press page-down
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
@@ -256,7 +262,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 2</span>,<span class="Constant"> 99</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># second sandbox shows in editor; scroll resets to display first sandbox</span>
   screen-should-contain [
@@ -275,7 +281,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes and scroll to second</span>
   assume-console [
@@ -287,7 +295,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
     press page-down
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
@@ -302,7 +310,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 2</span>,<span class="Constant"> 99</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># implicitly scroll up to first sandbox</span>
   screen-should-contain [
@@ -322,7 +330,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes</span>
   assume-console [
@@ -332,7 +342,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[add 1, 1]</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -352,7 +362,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># shouldn't go past last sandbox</span>
   screen-should-contain [
diff --git a/html/edit/008-sandbox-edit.mu.html b/html/edit/008-sandbox-edit.mu.html
index 97ca51e3..3725c7ce 100644
--- a/html/edit/008-sandbox-edit.mu.html
+++ b/html/edit/008-sandbox-edit.mu.html
@@ -34,28 +34,26 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <pre id='vimCodeElement'>
 <span class="SalientComment">## editing sandboxes after they've been created</span>
 
-<span class="muScenario">scenario</span> clicking-on-a-sandbox-moves-it-to-editor [
+<span class="muScenario">scenario</span> clicking-on-sandbox-edit-button-moves-it-to-editor [
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 2, 2]</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 2, 2                                         .</span>
+   <span class="Constant"> .                                                  ╎4                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -64,16 +62,13 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 55</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># it pops back into editor</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎                                                 .</span>
-   <span class="Constant"> .]                                                 ╎                                                 .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎add 2, 2                                         .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
   <span class="Comment"># cursor should be in the right place</span>
@@ -81,41 +76,36 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[0]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎0foo                                             .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎                                                 .</span>
-   <span class="Constant"> .]                                                 ╎                                                 .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎0add 2, 2                                        .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
 ]
 
-<span class="muScenario">scenario</span> clicking-on-a-sandbox-moves-it-to-editor-2 [
+<span class="muScenario">scenario</span> clicking-on-sandbox-edit-button-moves-it-to-editor-2 [
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># empty recipes</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[add 2, 2]</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎add 2, 2                                         .</span>
+   <span class="Constant"> .                                                  ╎4                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -124,16 +114,13 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 68</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># it pops back into editor</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎                                                 .</span>
-   <span class="Constant"> .]                                                 ╎                                                 .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎add 2, 2                                         .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
   <span class="Comment"># cursor should be in the right place</span>
@@ -141,15 +128,12 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[0]</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎0foo                                             .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎                                                 .</span>
-   <span class="Constant"> .]                                                 ╎                                                 .</span>
-   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎0add 2, 2                                        .</span>
+<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
 ]
@@ -212,13 +196,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">20/height</span>
   <span class="Comment"># left editor is empty</span>
-  <span class="Comment"># right editor contains an instruction</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[print-integer screen, 4]</span>
+  assume-resources [
+  ]
+  <span class="Comment"># right editor contains a print instruction</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[print-integer screen, 4]</span>
   <span class="Comment"># run the sandbox</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -239,7 +225,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 65</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
@@ -255,7 +241,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes and scroll to second</span>
   assume-console [
@@ -267,7 +255,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
     press page-down
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
@@ -282,7 +270,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 2</span>,<span class="Constant"> 55</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># second sandbox shows in editor; scroll resets to display first sandbox</span>
   screen-should-contain [
@@ -302,7 +290,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># initialize environment</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   render-all screen, env, render
   <span class="Comment"># create 2 sandboxes</span>
   assume-console [
@@ -312,7 +302,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     type <span class="Constant">[add 1, 1]</span>
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -331,7 +321,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># no change in contents</span>
   screen-should-contain [
@@ -353,7 +343,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press page-down
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># screen should show just final sandbox with the right index (1)</span>
   screen-should-contain [
diff --git a/html/edit/009-sandbox-test.mu.html b/html/edit/009-sandbox-test.mu.html
index 30c731ea..b6e0ab9b 100644
--- a/html/edit/009-sandbox-test.mu.html
+++ b/html/edit/009-sandbox-test.mu.html
@@ -40,22 +40,25 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  reply 4</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes:text, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  reply 4|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  reply 4                                         ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎foo                                              .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -65,7 +68,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 5</span>,<span class="Constant"> 51</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># color toggles to green</span>
   screen-should-contain-in-color <span class="Constant">2/green</span>, [
@@ -85,26 +88,24 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   ]
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .␣                                                 ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .␣ecipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  reply 4                                         ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎foo                                              .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎4                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
   <span class="Comment"># now change the result</span>
   <span class="Comment"># then rerun</span>
   assume-console [
-    left-click<span class="Constant"> 3</span>,<span class="Constant"> 11</span>  <span class="Comment"># cursor to end of line</span>
+    left-click<span class="Constant"> 2</span>,<span class="Constant"> 11</span>  <span class="Comment"># cursor to end of line</span>
     press backspace
     type <span class="Constant">[3]</span>
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># result turns red</span>
   screen-should-contain-in-color <span class="Constant">1/red</span>, [
@@ -131,14 +132,14 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     expected-response:text <span class="Special">&lt;-</span> get *curr, <span class="Constant">expected-response:offset</span>
     <span class="muControl">break-unless</span> expected-response
     filename <span class="Special">&lt;-</span> append filename, <span class="Constant">[.out]</span>
-    save filename, expected-response
+    resources <span class="Special">&lt;-</span> dump resources, filename, expected-response
   <span class="Delimiter">}</span>
 ]
 
 <span class="muRecipe">before</span> <span class="Constant">&lt;end-restore-sandbox&gt;</span> [
   <span class="Delimiter">{</span>
     filename <span class="Special">&lt;-</span> append filename, <span class="Constant">[.out]</span>
-    contents <span class="Special">&lt;-</span> restore filename
+    contents <span class="Special">&lt;-</span> slurp resources, filename
     <span class="muControl">break-unless</span> contents
     *curr <span class="Special">&lt;-</span> put *curr, <span class="Constant">expected-response:offset</span>, contents
   <span class="Delimiter">}</span>
@@ -163,7 +164,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     <span class="muControl">break-unless</span> sandbox
     <span class="Comment"># toggle its expected-response, and save session</span>
     sandbox <span class="Special">&lt;-</span> toggle-expected-response sandbox
-    save-sandboxes env
+    save-sandboxes env, resources
     hide-screen screen
     screen <span class="Special">&lt;-</span> render-sandbox-side screen, env, render
     screen <span class="Special">&lt;-</span> update-cursor screen, recipes, current-sandbox, sandbox-in-focus?, env
diff --git a/html/edit/010-sandbox-trace.mu.html b/html/edit/010-sandbox-trace.mu.html
index 66943462..ab32cbf0 100644
--- a/html/edit/010-sandbox-trace.mu.html
+++ b/html/edit/010-sandbox-trace.mu.html
@@ -40,22 +40,25 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  stash [abc]</span>
-]]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  stash [abc]</span>|
+<span class="Constant">      |]|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  stash [abc]                                     ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  stash [abc]                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎foo                                              .</span>
 <span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -64,17 +67,17 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 4</span>,<span class="Constant"> 51</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     cursor:char <span class="Special">&lt;-</span> copy <span class="Constant">9251/␣</span>
     print screen, cursor
   ]
   <span class="Comment"># trace now printed and cursor shouldn't have budged</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .␣                                                 ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  stash [abc]                                     ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .␣ecipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  stash [abc]                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎foo                                              .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎abc                                              .</span>
   ]
   screen-should-contain-in-color <span class="Constant">245/grey</span>, [
@@ -90,16 +93,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 4</span>,<span class="Constant"> 55</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
     print screen, cursor
   ]
   <span class="Comment"># trace hidden again</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .␣                                                 ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  stash [abc]                                     ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .␣ecipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  stash [abc]                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .                                                  ╎foo                                              .</span>
 <span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -110,24 +113,27 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># basic recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  stash [abc]</span>
-  <span class="muControl">reply</span><span class="Constant"> 4</span>
-]]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  stash [abc]</span>|
+      <span class="Constant">|</span>  <span class="muControl">reply</span> 4|
+<span class="Constant">      |]|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   <span class="Comment"># run it</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  stash [abc]                                     ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .  reply 4                                         ╎foo                                              .</span>
-   <span class="Constant"> .]                                                 ╎4                                                .</span>
+   <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  stash [abc]                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .                                                  ╎4                                                .</span>
 <span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
@@ -136,16 +142,16 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 4</span>,<span class="Constant"> 51</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># trace now printed above result</span>
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎                                                 .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  stash [abc]                                     ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .  reply 4                                         ╎foo                                              .</span>
-   <span class="Constant"> .]                                                 ╎abc                                              .</span>
+   <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
+   <span class="Constant"> .  stash [abc]                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  reply 4                                         ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .]                                                 ╎foo                                              .</span>
+   <span class="Constant"> .                                                  ╎abc                                              .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎8 instructions run                               .</span>
    <span class="Constant"> .                                                  ╎4                                                .</span>
    <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
@@ -157,13 +163,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[stash 123456789]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[stash 123456789]</span>
   <span class="Comment"># create and expand the trace</span>
   assume-console [
     press F4
     left-click<span class="Constant"> 4</span>,<span class="Constant"> 51</span>
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .                                                                                 run (F4)           .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
@@ -177,7 +185,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     left-click<span class="Constant"> 5</span>,<span class="Constant"> 57</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># no change; doesn't die</span>
   screen-should-contain [
diff --git a/html/edit/011-errors.mu.html b/html/edit/011-errors.mu.html
index 91e48c57..72f21172 100644
--- a/html/edit/011-errors.mu.html
+++ b/html/edit/011-errors.mu.html
@@ -40,12 +40,12 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 ]
 
 <span class="Comment"># copy code from recipe editor, persist to disk, load, save any errors</span>
-<span class="muRecipe">def!</span> update-recipes env:&amp;:environment, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, screen:&amp;:screen [
+<span class="muRecipe">def!</span> update-recipes env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen<span class="muRecipe"> -&gt; </span>errors-found?:bool, env:&amp;:environment, resources:&amp;:resources, screen:&amp;:screen [
   <span class="Constant">local-scope</span>
   <span class="Constant">load-ingredients</span>
   recipes:&amp;:editor <span class="Special">&lt;-</span> get *env, <span class="Constant">recipes:offset</span>
   in:text <span class="Special">&lt;-</span> editor-contents recipes
-  save <span class="Constant">[recipes.mu]</span>, in
+  resources <span class="Special">&lt;-</span> dump resources, <span class="Constant">[lesson/recipes.mu]</span>, in
   recipe-errors:text <span class="Special">&lt;-</span> reload in
   *env <span class="Special">&lt;-</span> put *env, <span class="Constant">recipe-errors:offset</span>, recipe-errors
   <span class="Comment"># if recipe editor has errors, stop</span>
@@ -153,23 +153,36 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  get 123:num, foo:offset</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  get 123:num, foo:offset|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
+  render-all screen, env, render
+  screen-should-contain [
+   <span class="Constant"> .                                                                                 run (F4)           .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  get 123:num, foo:offset                         ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
+  ]
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  get 123:num, foo:offset                         ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  get 123:num, foo:offset                         ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: unknown element 'foo' in container 'number'  ╎                                                 .</span>
    <span class="Constant"> .foo: first ingredient of 'get' should be a contai↩╎                                                 .</span>
    <span class="Constant"> .ner, but got '123:num'                            ╎                                                 .</span>
@@ -193,7 +206,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   assume-console [
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 80</span>
     <span class="Comment"># create invalid sandbox 1</span>
@@ -204,7 +219,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># status line shows that error is in first sandbox</span>
   screen-should-contain [
@@ -216,7 +231,9 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[]</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[]</span>
   assume-console [
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 80</span>
     <span class="Comment"># create invalid sandbox 2</span>
@@ -230,7 +247,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># status line shows that error is in second sandbox</span>
   screen-should-contain [
@@ -242,13 +259,13 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, <span class="Constant">[get foo, x:offset]</span>  <span class="Comment"># invalid</span>
+  assume-resources [
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[get foo, x:offset]</span>  <span class="Comment"># invalid</span>
   assume-console [
     press F4  <span class="Comment"># generate error</span>
   ]
-  run [
-    event-loop screen, console, env
-  ]
+  event-loop screen, console, env, resources
   assume-console [
     left-click<span class="Constant"> 3</span>,<span class="Constant"> 58</span>
     press ctrl-k
@@ -256,7 +273,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4  <span class="Comment"># update sandbox</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># error should disappear</span>
   screen-should-contain [
@@ -276,26 +293,31 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
   <span class="Comment"># define a shape-shifting recipe with an error</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[recipe foo x:_elem -&gt; z:_elem [</span>
-<span class="Constant">local-scope</span>
-<span class="Constant">load-ingredients</span>
-<span class="Constant">y:&amp;:num &lt;- copy 0</span>
-<span class="Constant">z &lt;- add x, y</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo 2]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo x:_elem<span class="muRecipe"> -&gt; </span>z:_elem <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  load-ingredients|</span>
+<span class="Constant">      |  y:&amp;:num &lt;- copy 0|</span>
+<span class="Constant">      |  z &lt;- add x, y|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo 2]</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .  errors found (0)                                                               run (F4)           .</span>
    <span class="Constant"> .recipe foo x:_elem -&gt; z:_elem [                   ╎                                                 .</span>
-   <span class="Constant"> .local-scope                                       ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .load-ingredients                                  ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .y:&amp;:num &lt;- copy 0                                 ╎foo 2                                            .</span>
-   <span class="Constant"> .z &lt;- add x, y                                     ╎foo_2: 'add' requires number ingredients, but go↩.</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  load-ingredients                                ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  y:&amp;:num &lt;- copy 0                               ╎foo 2                                            .</span>
+   <span class="Constant"> .  z &lt;- add x, y                                   ╎foo_2: 'add' requires number ingredients, but go↩.</span>
    <span class="Constant"> .]                                                 ╎t 'y'                                            .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
   <span class="Comment"># now rerun everything</span>
@@ -303,18 +325,19 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># error should remain unchanged</span>
   screen-should-contain [
    <span class="Constant"> .  errors found (0)                                                               run (F4)           .</span>
    <span class="Constant"> .recipe foo x:_elem -&gt; z:_elem [                   ╎                                                 .</span>
-   <span class="Constant"> .local-scope                                       ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .load-ingredients                                  ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .y:&amp;:num &lt;- copy 0                                 ╎foo 2                                            .</span>
-   <span class="Constant"> .z &lt;- add x, y                                     ╎foo_3: 'add' requires number ingredients, but go↩.</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  load-ingredients                                ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  y:&amp;:num &lt;- copy 0                               ╎foo 2                                            .</span>
+   <span class="Constant"> .  z &lt;- add x, y                                   ╎foo_3: 'add' requires number ingredients, but go↩.</span>
    <span class="Constant"> .]                                                 ╎t 'y'                                            .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
 ]
@@ -324,17 +347,21 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
   <span class="Comment"># overload a well-known shape-shifting recipe</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[recipe length l:&amp;:list:_elem -&gt; n:num [</span>
-<span class="Constant">]</span>]
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> length l:&amp;:list:_elem<span class="muRecipe"> -&gt; </span>n:num <span class="Constant">[|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
   <span class="Comment"># call code that uses other variants of it, but not it itself</span>
-  sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[x:&amp;:list:num &lt;- copy 0</span>
+  test-sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[x:&amp;:list:num &lt;- copy 0</span>
 <span class="Constant">to-text x]</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, sandbox
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, test-sandbox
   <span class="Comment"># run it once</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   <span class="Comment"># no errors anywhere on screen (can't check anything else, since to-text will return an address)</span>
   screen-should-contain-in-color <span class="Constant">1/red</span>, [
    <span class="Constant"> .                                                                                                    .</span>
@@ -358,7 +385,7 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># still no errors</span>
   screen-should-contain-in-color <span class="Constant">1/red</span>, [
@@ -384,24 +411,30 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  x &lt;- copy 0</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  x &lt;- copy 0|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  x &lt;- copy 0                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  x &lt;- copy 0                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: missing type for 'x' in 'x &lt;- copy 0'        ╎                                                 .</span>
+   <span class="Constant"> .foo: can't copy '0' to 'x'; types don't match     ╎                                                 .</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
 ]
 
@@ -410,22 +443,23 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
   <span class="Comment"># recipe is incomplete (unbalanced '[')</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo \\[</span>
-<span class="Constant">  x &lt;- copy 0</span>
-<span class="Constant">]</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo \\\<span class="Constant">[|</span>
+<span class="Constant">      |  x &lt;- copy 0|</span>
+<span class="Constant">    ]</span>
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo \\[                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  x &lt;- copy 0                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo \\[                                      ╎foo                                              .</span>
+   <span class="Constant"> .  x &lt;- copy 0                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .9: unbalanced '\\[' for recipe                      ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
@@ -437,27 +471,30 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  local-scope</span>
-<span class="Constant">  x:&amp;:point &lt;- new point:type</span>
-<span class="Constant">  get x:&amp;:point, 1:offset</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  x:&amp;:point &lt;- new point:type|</span>
+<span class="Constant">      |  get x:&amp;:point, 1:offset|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  local-scope                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .  x:&amp;:point &lt;- new point:type                     ╎                                                 .</span>
    <span class="Constant"> .  get x:&amp;:point, 1:offset                         ╎                                                 .</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: first ingredient of 'get' should be a contai↩╎                                                 .</span>
    <span class="Constant"> .ner, but got 'x:&amp;:point'                          ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
@@ -469,29 +506,32 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  local-scope</span>
-<span class="Constant">  x:num &lt;- copy 0</span>
-<span class="Constant">  y:&amp;:point &lt;- new point:type</span>
-<span class="Constant">  get *y:&amp;:point, x:num</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  x:num &lt;- copy 0|</span>
+<span class="Constant">      |  y:&amp;:point &lt;- new point:type|</span>
+<span class="Constant">      |  get *y:&amp;:point, x:num|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  local-scope                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .  x:num &lt;- copy 0                                 ╎                                                 .</span>
    <span class="Constant"> .  y:&amp;:point &lt;- new point:type                     ╎                                                 .</span>
    <span class="Constant"> .  get *y:&amp;:point, x:num                           ╎                                                 .</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: second ingredient of 'get' should have type ↩╎                                                 .</span>
    <span class="Constant"> .'offset', but got 'x:num'                         ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
@@ -502,25 +542,28 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
 <span class="muScenario">scenario</span> run-shows-errors-everytime [
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
-  <span class="Comment"># try to run a file with an error</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">15/height</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[ </span>
-<span class="Constant">recipe foo [</span>
-<span class="Constant">  local-scope</span>
-<span class="Constant">  x:num &lt;- copy y:num</span>
-<span class="Constant">]</span>]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># try to run a file with an error</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  x:num &lt;- copy y:num|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  local-scope                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .  x:num &lt;- copy y:num                             ╎                                                 .</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: tried to read ingredient 'y' in 'x:num &lt;- co↩╎                                                 .</span>
    <span class="Constant"> .py y:num' but it hasn't been written to yet       ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
@@ -531,15 +574,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found                                                                   run (F4)           .</span>
-   <span class="Constant"> .                                                  ╎foo                                              .</span>
-   <span class="Constant"> .recipe foo [                                      ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .  local-scope                                     ╎                                                 .</span>
+   <span class="Constant"> .recipe foo [                                      ╎foo                                              .</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .  x:num &lt;- copy y:num                             ╎                                                 .</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
    <span class="Constant"> .foo: tried to read ingredient 'y' in 'x:num &lt;- co↩╎                                                 .</span>
    <span class="Constant"> .py y:num' but it hasn't been written to yet       ╎                                                 .</span>
    <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
@@ -551,15 +594,15 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># right editor contains an illegal instruction</span>
-  sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[get 1234:num, foo:offset]</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, sandbox
-  <span class="Comment"># run the code in the editors</span>
+  assume-resources [
+  ]
+  <span class="Comment"># sandbox editor contains an illegal instruction</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[get 1234:num, foo:offset]</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that screen prints error message in red</span>
   screen-should-contain [
@@ -613,16 +656,17 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
-  <span class="Comment"># right editor contains an illegal instruction</span>
-  sandbox:text <span class="Special">&lt;-</span> new <span class="Constant">[get 1234:num, foo:offset]</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, <span class="Constant">[]</span>, sandbox
+  assume-resources [
+  ]
+  <span class="Comment"># sandbox editor contains an illegal instruction</span>
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[get 1234:num, foo:offset]</span>
   <span class="Comment"># run the code in the editors multiple times</span>
   assume-console [
     press F4
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># check that screen prints error message just once</span>
   screen-should-contain [
@@ -643,20 +687,23 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   <span class="Constant">local-scope</span>
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">20/height</span>
-  <span class="Comment"># left editor is empty</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[recipe foo [</span>
-<span class="Constant">  {</span>
-<span class="Constant">    loop</span>
-<span class="Constant">  }</span>
-<span class="Constant">]</span>]
-  <span class="Comment"># right editor contains an instruction</span>
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo]</span>
+  <span class="Comment"># sandbox editor will trigger an infinite loop</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  {|</span>
+<span class="Constant">      |    loop|</span>
+<span class="Constant">      |  }|</span>
+<span class="Constant">      |]</span>|
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo]</span>
   <span class="Comment"># run the sandbox</span>
   assume-console [
     press F4
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   screen-should-contain [
    <span class="Constant"> .  errors found (0)                                                               run (F4)           .</span>
@@ -665,7 +712,8 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
    <span class="Constant"> .    loop                                          ╎0   edit          copy            delete         .</span>
    <span class="Constant"> .  }                                               ╎foo                                              .</span>
    <span class="Constant"> .]                                                 ╎took too long!                                   .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎                                                 .</span>
    <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
 ]
@@ -675,51 +723,56 @@ body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color
   trace-until <span class="Constant">100/app</span>  <span class="Comment"># trace too long</span>
   assume-screen <span class="Constant">100/width</span>, <span class="Constant">10/height</span>
   <span class="Comment"># generate a stash and a error</span>
-  recipes:text <span class="Special">&lt;-</span> new <span class="Constant">[recipe foo [</span>
-<span class="Constant">local-scope</span>
-<span class="Constant">a:num &lt;- next-ingredient</span>
-<span class="Constant">b:num &lt;- next-ingredient</span>
-<span class="Constant">stash [dividing by]</span>, b
-_, c:num <span class="Special">&lt;-</span> divide-with-remainder a, b
-<span class="muControl">reply</span> b
-]]
-  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment screen, recipes, <span class="Constant">[foo 4, 0]</span>
+  assume-resources [
+    <span class="Constant">[lesson/recipes.mu]</span> <span class="Special">&lt;-</span> [
+      <span class="Constant">|recipe</span> foo <span class="Constant">[|</span>
+<span class="Constant">      |  local-scope|</span>
+<span class="Constant">      |  a:num &lt;- next-ingredient|</span>
+<span class="Constant">      |  b:num &lt;- next-ingredient|</span>
+<span class="Constant">      |  stash [dividing by]</span>, b|
+      <span class="Constant">|</span>  _, c:num <span class="Special">&lt;-</span> divide-with-remainder a, b|
+      <span class="Constant">|</span>  <span class="muControl">reply</span> b|
+<span class="Constant">      |]|</span>
+    ]
+  ]
+  env:&amp;:environment <span class="Special">&lt;-</span> new-programming-environment resources, screen, <span class="Constant">[foo 4, 0]</span>
   <span class="Comment"># run</span>
   assume-console [
     press F4
   ]
-  event-loop screen, console, env
+  event-loop screen, console, env, resources
   <span class="Comment"># screen prints error message</span>
   screen-should-contain [
    <span class="Constant"> .  errors found (0)                                                               run (F4)           .</span>
    <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
-   <span class="Constant"> .local-scope                                       ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .a:num &lt;- next-ingredient                          ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .b:num &lt;- next-ingredient                          ╎foo 4, 0                                         .</span>
-   <span class="Constant"> .stash [dividing by], b                            ╎foo: divide by zero in '_, c:num &lt;- divide-with-↩.</span>
-   <span class="Constant"> ._, c:num &lt;- divide-with-remainder a, b            ╎remainder a, b'                                  .</span>
-   <span class="Constant"> .reply b                                           ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  a:num &lt;- next-ingredient                        ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  b:num &lt;- next-ingredient                        ╎foo 4, 0                                         .</span>
+   <span class="Constant"> .  stash [dividing by], b                          ╎foo: divide by zero in '_, c:num &lt;- divide-with-↩.</span>
+   <span class="Constant"> .  _, c:num &lt;- divide-with-remainder a, b          ╎remainder a, b'                                  .</span>
+   <span class="Constant"> .  reply b                                         ╎─────────────────────────────────────────────────.</span>
    <span class="Constant"> .]                                                 ╎                                                 .</span>
+   <span class="Constant"> .                                                  ╎                                                 .</span>
   ]
   <span class="Comment"># click on the call in the sandbox</span>
   assume-console [
     left-click<span class="Constant"> 4</span>,<span class="Constant"> 55</span>
   ]
   run [
-    event-loop screen, console, env
+    event-loop screen, console, env, resources
   ]
   <span class="Comment"># screen should expand trace</span>
   screen-should-contain [
    <span class="Constant"> .  errors found (0)                                                               run (F4)           .</span>
    <span class="Constant"> .recipe foo [                                      ╎                                                 .</span>
-   <span class="Constant"> .local-scope                                       ╎─────────────────────────────────────────────────.</span>
-   <span class="Constant"> .a:num &lt;- next-ingredient                          ╎0   edit          copy            delete         .</span>
-   <span class="Constant"> .b:num &lt;- next-ingredient                          ╎foo 4, 0                                         .</span>
-   <span class="Constant"> .stash [dividing by], b                            ╎dividing by 0                                    .</span>
-   <span class="Constant"> ._, c:num &lt;- divide-with-remainder a, b            ╎14 instructions run                              .</span>
-   <span class="Constant"> .reply b                                           ╎foo: divide by zero in '_, c:num &lt;- divide-with-↩.</span>
+   <span class="Constant"> .  local-scope                                     ╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .  a:num &lt;- next-ingredient                        ╎0   edit          copy            delete         .</span>
+   <span class="Constant"> .  b:num &lt;- next-ingredient                        ╎foo 4, 0                                         .</span>
+   <span class="Constant"> .  stash [dividing by], b                          ╎dividing by 0                                    .</span>
+   <span class="Constant"> .  _, c:num &lt;- divide-with-remainder a, b          ╎14 instructions run                              .</span>
+   <span class="Constant"> .  reply b                                         ╎foo: divide by zero in '_, c:num &lt;- divide-with-↩.</span>
    <span class="Constant"> .]                                                 ╎remainder a, b'                                  .</span>
-<span class="Constant">    .╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╎─────────────────────────────────────────────────.</span>
+   <span class="Constant"> .                                                  ╎─────────────────────────────────────────────────.</span>
   ]
 ]
 </pre>
author	Kartik K. Agaram <vc@akkartik.com>	2016-12-11 16:18:18 -0800
committer	Kartik K. Agaram <vc@akkartik.com>	2016-12-11 16:18:18 -0800
commit	294b2ab35983ebe95698835bb54bca8bd3eec101 (patch)
tree	fbc74bea6cefd7b8f527d36a7b7c6804dd886414 /html
parent	d5c86dfd8706e6b3ceee7843464797e6fcad4259 (diff)
download	mu-294b2ab35983ebe95698835bb54bca8bd3eec101.tar.gz