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authorKartik K. Agaram <vc@akkartik.com>2016-05-21 17:44:53 -0700
committerKartik K. Agaram <vc@akkartik.com>2016-05-21 17:44:53 -0700
commit2f02189ddcdeb7d25b0ca9bd5b955b764d41a1a7 (patch)
tree7c2e8b6e37ae3201dc01e90bcb390ee60b7f4a77 /html/032array.cc.html
parent61c025b11ed4ddd002f09f061fd77c75d8b6d0ba (diff)
downloadmu-2f02189ddcdeb7d25b0ca9bd5b955b764d41a1a7.tar.gz
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+<!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 - 032array.cc</title>
+<meta name="Generator" content="Vim/7.4">
+<meta name="plugin-version" content="vim7.4_v2">
+<meta name="syntax" content="cpp">
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+<!--
+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; }
+.cSpecial { color: #008000; }
+.traceContains { color: #008000; }
+.SalientComment { color: #00ffff; }
+.Comment { color: #9090ff; }
+.Delimiter { color: #800080; }
+.Special { color: #c00000; }
+.Identifier { color: #fcb165; }
+.Normal { color: #eeeeee; background-color: #080808; padding-bottom: 1px; }
+-->
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+
+<script type='text/javascript'>
+<!--
+
+-->
+</script>
+</head>
+<body>
+<pre id='vimCodeElement'>
+<span class="Comment">//: Arrays contain a variable number of elements of the same type. Their value</span>
+<span class="Comment">//: starts with the length of the array.</span>
+<span class="Comment">//:</span>
+<span class="Comment">//: You can create arrays of containers, but containers can only contain</span>
+<span class="Comment">//: elements of a fixed size, so you can't create containers containing arrays.</span>
+<span class="Comment">//: Create containers containing addresses to arrays instead.</span>
+
+<span class="Comment">//: You can create arrays using 'create-array'.</span>
+<span class="Delimiter">:(scenario create_array)</span>
+def main [
+  <span class="Comment"># create an array occupying locations 1 (for the size) and 2-4 (for the elements)</span>
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+]
+<span class="traceContains">+run: creating array of size 4</span>
+
+<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
+CREATE_ARRAY<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;create-array&quot;</span><span class="Delimiter">,</span> CREATE_ARRAY<span class="Delimiter">);</span>
+<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
+<span class="Normal">case</span> CREATE_ARRAY: <span class="Delimiter">{</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>empty<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;'create-array' needs one product and no ingredients but got '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<span class="Delimiter">)</span> &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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> product = inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
+  <span class="Comment">// Update CREATE_ARRAY product in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_array<span class="Delimiter">(</span>product<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;'create-array' cannot create non-array '&quot;</span> &lt;&lt; product<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>!product<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<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;create array of what? '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<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="Comment">// 'create-array' will need to check properties rather than types</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!product<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<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;create array of what size? '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<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_integer<span class="Delimiter">(</span>product<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<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;'create-array' product should specify size of array after its element type, but got '&quot;</span> &lt;&lt; product<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name &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> CREATE_ARRAY: <span class="Delimiter">{</span>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> product = current_instruction<span class="Delimiter">().</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
+  <span class="Comment">// Update CREATE_ARRAY product in Run</span>
+  <span class="Normal">int</span> base_address = product<span class="Delimiter">.</span>value<span class="Delimiter">;</span>
+  <span class="Normal">int</span> array_length = to_integer<span class="Delimiter">(</span>product<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<span class="Delimiter">);</span>
+  <span class="Comment">// initialize array size, so that size_of will work</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9999</span><span class="Delimiter">,</span> <span class="Constant">&quot;mem&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;storing &quot;</span> &lt;&lt; array_length &lt;&lt; <span class="Constant">&quot; in location &quot;</span> &lt;&lt; base_address &lt;&lt; end<span class="Delimiter">();</span>
+  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> base_address<span class="Delimiter">,</span> array_length<span class="Delimiter">);</span>  <span class="Comment">// in array elements</span>
+  <span class="Normal">int</span> size = size_of<span class="Delimiter">(</span>product<span class="Delimiter">);</span>  <span class="Comment">// in locations</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9998</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;creating array of size &quot;</span> &lt;&lt; size &lt;&lt; end<span class="Delimiter">();</span>
+  <span class="Comment">// initialize array</span>
+  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">1</span><span class="Delimiter">;</span> i &lt;= size_of<span class="Delimiter">(</span>product<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> base_address+i<span class="Delimiter">,</span> <span class="Constant">0</span><span class="Delimiter">);</span>
+  <span class="Delimiter">}</span>
+  <span class="Comment">// no need to update product</span>
+  <span class="Identifier">goto</span> finish_instruction<span class="Delimiter">;</span>
+<span class="Delimiter">}</span>
+
+<span class="Delimiter">:(scenario copy_array)</span>
+<span class="Comment"># Arrays can be copied around with a single instruction just like numbers,</span>
+<span class="Comment"># no matter how large they are.</span>
+<span class="Comment"># You don't need to pass the size around, since each array variable stores its</span>
+<span class="Comment"># size in memory at run-time. We'll call a variable with an explicit size a</span>
+<span class="Comment"># 'static' array, and one without a 'dynamic' array since it can contain</span>
+<span class="Comment"># arrays of many different sizes.</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:array:number<span class="Special"> &lt;- </span>copy <span class="Constant">1</span>:array:number:<span class="Constant">3</span>
+]
+<span class="traceContains">+mem: storing 3 in location 5</span>
+<span class="traceContains">+mem: storing 14 in location 6</span>
+<span class="traceContains">+mem: storing 15 in location 7</span>
+<span class="traceContains">+mem: storing 16 in location 8</span>
+
+<span class="Delimiter">:(scenario stash_array)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  stash [foo:]<span class="Delimiter">,</span> <span class="Constant">1</span>:array:number:<span class="Constant">3</span>
+]
+<span class="traceContains">+app: foo: 3 14 15 16</span>
+
+<span class="Delimiter">:(before &quot;End size_of(reagent r) Cases&quot;)</span>
+<span class="Normal">if</span> <span class="Delimiter">(</span>r<span class="Delimiter">.</span>type &amp;&amp; r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;array&quot;</span><span class="Delimiter">))</span> <span class="Delimiter">{</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!r<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;'&quot;</span> &lt;&lt; r<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;' is an array of what?</span><span class="cSpecial">\n</span><span class="Constant">&quot;</span> &lt;&lt; end<span class="Delimiter">();</span>
+    <span class="Identifier">return</span> <span class="Constant">1</span><span class="Delimiter">;</span>
+  <span class="Delimiter">}</span>
+  type_tree* element_type = copy_array_element<span class="Delimiter">(</span>r<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  <span class="Normal">int</span> result = <span class="Constant">1</span> + array_length<span class="Delimiter">(</span>r<span class="Delimiter">)</span>*size_of<span class="Delimiter">(</span>element_type<span class="Delimiter">);</span>
+  <span class="Normal">delete</span> element_type<span class="Delimiter">;</span>
+  <span class="Identifier">return</span> result<span class="Delimiter">;</span>
+<span class="Delimiter">}</span>
+
+<span class="Comment">//: disable the size mismatch check for arrays since the destination array</span>
+<span class="Comment">//: need not be initialized</span>
+<span class="Delimiter">:(before &quot;End size_mismatch(x) Cases&quot;)</span>
+<span class="Normal">if</span> <span class="Delimiter">(</span>x<span class="Delimiter">.</span>type &amp;&amp; x<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>value == get<span class="Delimiter">(</span>Type_ordinal<span class="Delimiter">,</span> <span class="Constant">&quot;array&quot;</span><span class="Delimiter">))</span> <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
+
+<span class="Comment">//: arrays are disallowed inside containers unless their length is fixed in</span>
+<span class="Comment">//: advance</span>
+
+<span class="Delimiter">:(scenario container_contains_array)</span>
+container foo [
+  <span class="Normal">x</span>:array:number:<span class="Constant">3</span>
+]
+$error: <span class="Constant">0</span>
+
+<span class="Delimiter">:(scenario container_disallows_dynamic_array_element)</span>
+<span class="Special">% Hide_errors = true;</span>
+container foo [
+  <span class="Normal">x</span>:array:number
+]
+<span class="traceContains">+error: container 'foo' cannot determine size of element 'x'</span>
+
+<span class="Delimiter">:(before &quot;End Load Container Element Definition&quot;)</span>
+<span class="Delimiter">{</span>
+  <span class="Normal">const</span> type_tree* type = info<span class="Delimiter">.</span>elements<span class="Delimiter">.</span>back<span class="Delimiter">().</span>type<span class="Delimiter">;</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>name == <span class="Constant">&quot;array&quot;</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    <span class="Normal">if</span> <span class="Delimiter">(</span>!type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+      raise &lt;&lt; <span class="Constant">&quot;container '&quot;</span> &lt;&lt; name &lt;&lt; <span class="Constant">&quot;' doesn't specify type of array elements for '&quot;</span> &lt;&lt; info<span class="Delimiter">.</span>elements<span class="Delimiter">.</span>back<span class="Delimiter">().</span>name &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">continue</span><span class="Delimiter">;</span>
+    <span class="Delimiter">}</span>
+    <span class="Normal">if</span> <span class="Delimiter">(</span>!type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">)</span> <span class="Delimiter">{</span>  <span class="Comment">// array has no length</span>
+      raise &lt;&lt; <span class="Constant">&quot;container '&quot;</span> &lt;&lt; name &lt;&lt; <span class="Constant">&quot;' cannot determine size of element '&quot;</span> &lt;&lt; info<span class="Delimiter">.</span>elements<span class="Delimiter">.</span>back<span class="Delimiter">().</span>name &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">continue</span><span class="Delimiter">;</span>
+    <span class="Delimiter">}</span>
+  <span class="Delimiter">}</span>
+<span class="Delimiter">}</span>
+
+<span class="SalientComment">//:: To access elements of an array, use 'index'</span>
+
+<span class="Delimiter">:(scenario index)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>index <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Delimiter">,</span> <span class="Constant">0</span>
+]
+<span class="traceContains">+mem: storing 14 in location 5</span>
+
+<span class="Delimiter">:(scenario index_direct_offset)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>index <span class="Constant">1</span>:array:number<span class="Delimiter">,</span> <span class="Constant">5</span>:number
+]
+<span class="traceContains">+mem: storing 14 in location 6</span>
+
+<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
+INDEX<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;index&quot;</span><span class="Delimiter">,</span> INDEX<span class="Delimiter">);</span>
+<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
+<span class="Normal">case</span> INDEX: <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;'index' expects exactly 2 ingredients in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> base = 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="Comment">// Update INDEX base in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_array<span class="Delimiter">(</span>base<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;'index' on a non-array '&quot;</span> &lt;&lt; base<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> index = 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="Comment">// Update INDEX index in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_number<span class="Delimiter">(</span>index<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 'index' should be a number, but got '&quot;</span> &lt;&lt; index<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>inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>empty<span class="Delimiter">())</span> <span class="Identifier">break</span><span class="Delimiter">;</span>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> product = inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">);</span>
+  <span class="Comment">// Update INDEX product in Check</span>
+  reagent element<span class="Delimiter">;</span>
+  element<span class="Delimiter">.</span>type = copy_array_element<span class="Delimiter">(</span>base<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!types_coercible<span class="Delimiter">(</span>product<span class="Delimiter">,</span> element<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;'index' on '&quot;</span> &lt;&lt; base<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;' can't be saved in '&quot;</span> &lt;&lt; product<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;'; type should be '&quot;</span> &lt;&lt; names_to_string_without_quotes<span class="Delimiter">(</span>element<span class="Delimiter">.</span>type<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> INDEX: <span class="Delimiter">{</span>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> base = 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="Comment">// Update INDEX base in Run</span>
+  <span class="Normal">int</span> base_address = base<span class="Delimiter">.</span>value<span class="Delimiter">;</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9998</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;base address is &quot;</span> &lt;&lt; base_address &lt;&lt; end<span class="Delimiter">();</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>base_address == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;tried to access location 0 in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>current_instruction<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> index = current_instruction<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="Comment">// Update INDEX index in Run</span>
+  vector&lt;<span class="Normal">double</span>&gt; index_val<span class="Delimiter">(</span>read_memory<span class="Delimiter">(</span>index<span class="Delimiter">));</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span> &lt; <span class="Constant">0</span> || index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span> &gt;= get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> base_address<span class="Delimiter">))</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;invalid index &quot;</span> &lt;&lt; no_scientific<span class="Delimiter">(</span>index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">))</span> &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>
+  type_tree* element_type = copy_array_element<span class="Delimiter">(</span>base<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  <span class="Normal">int</span> src = base_address + <span class="Constant">1</span> + index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span>*size_of<span class="Delimiter">(</span>element_type<span class="Delimiter">);</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9998</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;address to copy is &quot;</span> &lt;&lt; src &lt;&lt; end<span class="Delimiter">();</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9998</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;its type is &quot;</span> &lt;&lt; get<span class="Delimiter">(</span>Type<span class="Delimiter">,</span> element_type<span class="Delimiter">-&gt;</span>value<span class="Delimiter">).</span>name &lt;&lt; end<span class="Delimiter">();</span>
+  reagent element<span class="Delimiter">;</span>
+  element<span class="Delimiter">.</span>set_value<span class="Delimiter">(</span>src<span class="Delimiter">);</span>
+  element<span class="Delimiter">.</span>type = element_type<span class="Delimiter">;</span>
+  <span class="Comment">// Read element</span>
+  products<span class="Delimiter">.</span>push_back<span class="Delimiter">(</span>read_memory<span class="Delimiter">(</span>element<span class="Delimiter">));</span>
+  <span class="Identifier">break</span><span class="Delimiter">;</span>
+<span class="Delimiter">}</span>
+
+<span class="Delimiter">:(code)</span>
+type_tree* copy_array_element<span class="Delimiter">(</span><span class="Normal">const</span> type_tree* type<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>left<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    assert<span class="Delimiter">(</span>!type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>left<span class="Delimiter">-&gt;</span>left<span class="Delimiter">);</span>
+    <span class="Identifier">return</span> <span class="Normal">new</span> type_tree<span class="Delimiter">(</span>*type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>left<span class="Delimiter">);</span>
+  <span class="Delimiter">}</span>
+  assert<span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">);</span>
+  <span class="Comment">// array:&lt;type&gt;:&lt;size&gt;? return just &lt;type&gt;</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right &amp;&amp; is_integer<span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<span class="Delimiter">))</span>
+    <span class="Identifier">return</span> <span class="Normal">new</span> type_tree<span class="Delimiter">(</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<span class="Delimiter">,</span> type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>value<span class="Delimiter">);</span>  <span class="Comment">// snip type-&gt;right-&gt;right</span>
+  <span class="Identifier">return</span> <span class="Normal">new</span> type_tree<span class="Delimiter">(</span>*type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">);</span>
+<span class="Delimiter">}</span>
+
+<span class="Normal">int</span> array_length<span class="Delimiter">(</span><span class="Normal">const</span> reagent&amp; x<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>x<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right &amp;&amp; !x<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right  <span class="Comment">// exactly 3 types</span>
+      &amp;&amp; is_integer<span class="Delimiter">(</span>x<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<span class="Delimiter">))</span> <span class="Delimiter">{</span>  <span class="Comment">// third 'type' is a number</span>
+    <span class="Comment">// get size from type</span>
+    <span class="Identifier">return</span> to_integer<span class="Delimiter">(</span>x<span class="Delimiter">.</span>type<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>right<span class="Delimiter">-&gt;</span>name<span class="Delimiter">);</span>
+  <span class="Delimiter">}</span>
+  <span class="Comment">// this should never happen at transform time</span>
+  <span class="Comment">// x should already be canonized.</span>
+  <span class="Identifier">return</span> get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> x<span class="Delimiter">.</span>value<span class="Delimiter">);</span>
+<span class="Delimiter">}</span>
+
+<span class="Normal">void</span> test_array_length_compound<span class="Delimiter">()</span> <span class="Delimiter">{</span>
+  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> <span class="Constant">1</span><span class="Delimiter">,</span> <span class="Constant">3</span><span class="Delimiter">);</span>
+  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> <span class="Constant">2</span><span class="Delimiter">,</span> <span class="Constant">14</span><span class="Delimiter">);</span>
+  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> <span class="Constant">3</span><span class="Delimiter">,</span> <span class="Constant">15</span><span class="Delimiter">);</span>
+  put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> <span class="Constant">4</span><span class="Delimiter">,</span> <span class="Constant">16</span><span class="Delimiter">);</span>
+  reagent x<span class="Delimiter">(</span><span class="Constant">&quot;1:array:address:number&quot;</span><span class="Delimiter">);</span>  <span class="Comment">// 3 types, but not a static array</span>
+  populate_value<span class="Delimiter">(</span>x<span class="Delimiter">);</span>
+  CHECK_EQ<span class="Delimiter">(</span>array_length<span class="Delimiter">(</span>x<span class="Delimiter">),</span> <span class="Constant">3</span><span class="Delimiter">);</span>
+<span class="Delimiter">}</span>
+
+<span class="Delimiter">:(scenario index_out_of_bounds)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">7</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  index <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Delimiter">,</span> <span class="Constant">4</span>  <span class="Comment"># less than size of array in locations, but larger than its length in elements</span>
+]
+<span class="traceContains">+error: main: invalid index 4</span>
+
+<span class="Delimiter">:(scenario index_out_of_bounds_2)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  <span class="Constant">1</span>:array:point:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">7</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  index <span class="Constant">1</span>:array:point<span class="Delimiter">,</span> -<span class="Constant">1</span>
+]
+<span class="traceContains">+error: main: invalid index -1</span>
+
+<span class="Delimiter">:(scenario index_product_type_mismatch)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  <span class="Constant">1</span>:array:point:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">7</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">9</span>:number<span class="Special"> &lt;- </span>index <span class="Constant">1</span>:array:point<span class="Delimiter">,</span> <span class="Constant">0</span>
+]
+<span class="traceContains">+error: main: 'index' on '1:array:point' can't be saved in '9:number'; type should be 'point'</span>
+
+<span class="Comment">//: we might want to call 'index' without saving the results, say in a sandbox</span>
+
+<span class="Delimiter">:(scenario index_without_product)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  index <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Delimiter">,</span> <span class="Constant">0</span>
+]
+<span class="Comment"># just don't die</span>
+
+<span class="SalientComment">//:: To write to elements of arrays, use 'put'.</span>
+
+<span class="Delimiter">:(scenario put_index)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">1</span>:array:number<span class="Special"> &lt;- </span>put-index <span class="Constant">1</span>:array:number<span class="Delimiter">,</span> <span class="Constant">1</span><span class="Delimiter">,</span> <span class="Constant">34</span>
+]
+<span class="traceContains">+mem: storing 34 in location 3</span>
+
+<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
+PUT_INDEX<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;put-index&quot;</span><span class="Delimiter">,</span> PUT_INDEX<span class="Delimiter">);</span>
+<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
+<span class="Normal">case</span> PUT_INDEX: <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">3</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;'put-index' expects exactly 3 ingredients in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> base = 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="Comment">// Update PUT_INDEX base in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_array<span class="Delimiter">(</span>base<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;'put-index' on a non-array '&quot;</span> &lt;&lt; base<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> index = 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="Comment">// Update PUT_INDEX index in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_number<span class="Delimiter">(</span>index<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 'put-index' should have type 'number', but got '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> value = inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">);</span>
+  <span class="Comment">// Update PUT_INDEX value in Check</span>
+  reagent element<span class="Delimiter">;</span>
+  element<span class="Delimiter">.</span>type = copy_array_element<span class="Delimiter">(</span>base<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!types_coercible<span class="Delimiter">(</span>element<span class="Delimiter">,</span> value<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;'put-index &quot;</span> &lt;&lt; base<span class="Delimiter">.</span>original_string &lt;&lt; <span class="Constant">&quot;, &quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">1</span><span class="Delimiter">).</span>original_string &lt;&lt; <span class="Constant">&quot;' should store &quot;</span> &lt;&lt; names_to_string_without_quotes<span class="Delimiter">(</span>element<span class="Delimiter">.</span>type<span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot; but '&quot;</span> &lt;&lt; value<span class="Delimiter">.</span>name &lt;&lt; <span class="Constant">&quot;' has type &quot;</span> &lt;&lt; names_to_string_without_quotes<span class="Delimiter">(</span>value<span class="Delimiter">.</span>type<span class="Delimiter">)</span> &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="Normal">if</span> <span class="Delimiter">(</span>!inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>empty<span class="Delimiter">()</span> &amp;&amp; inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>name != inst<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>
+    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;product of 'put-index' must be first ingredient '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">).</span>original_string &lt;&lt; <span class="Constant">&quot;', but got '&quot;</span> &lt;&lt; inst<span class="Delimiter">.</span>products<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><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="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> PUT_INDEX: <span class="Delimiter">{</span>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> base = 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="Comment">// Update PUT_INDEX base in Run</span>
+  <span class="Normal">int</span> base_address = base<span class="Delimiter">.</span>value<span class="Delimiter">;</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>base_address == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;tried to access location 0 in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>current_instruction<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> index = current_instruction<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="Comment">// Update PUT_INDEX index in Run</span>
+  vector&lt;<span class="Normal">double</span>&gt; index_val<span class="Delimiter">(</span>read_memory<span class="Delimiter">(</span>index<span class="Delimiter">));</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span> &lt; <span class="Constant">0</span> || index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span> &gt;= get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> base_address<span class="Delimiter">))</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;invalid index &quot;</span> &lt;&lt; no_scientific<span class="Delimiter">(</span>index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">))</span> &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>
+  reagent element<span class="Delimiter">;</span>
+  element<span class="Delimiter">.</span>type = copy_array_element<span class="Delimiter">(</span>base<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  <span class="Normal">int</span> address = base_address + <span class="Constant">1</span> + index_val<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">0</span><span class="Delimiter">)</span>*size_of<span class="Delimiter">(</span>element<span class="Delimiter">.</span>type<span class="Delimiter">);</span>
+  element<span class="Delimiter">.</span>value = address<span class="Delimiter">;</span>
+  trace<span class="Delimiter">(</span><span class="Constant">9998</span><span class="Delimiter">,</span> <span class="Constant">&quot;run&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;address to copy to is &quot;</span> &lt;&lt; address &lt;&lt; end<span class="Delimiter">();</span>
+  <span class="Comment">// optimization: directly write the element rather than updating 'product'</span>
+  <span class="Comment">// and writing the entire array</span>
+  vector&lt;<span class="Normal">double</span>&gt; value = read_memory<span class="Delimiter">(</span>current_instruction<span class="Delimiter">().</span>ingredients<span class="Delimiter">.</span>at<span class="Delimiter">(</span><span class="Constant">2</span><span class="Delimiter">));</span>
+  <span class="Comment">// Write Memory in PUT_INDEX in Run</span>
+  <span class="Normal">for</span> <span class="Delimiter">(</span><span class="Normal">int</span> i = <span class="Constant">0</span><span class="Delimiter">;</span> i &lt; SIZE<span class="Delimiter">(</span>value<span class="Delimiter">);</span> ++i<span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    trace<span class="Delimiter">(</span><span class="Constant">9999</span><span class="Delimiter">,</span> <span class="Constant">&quot;mem&quot;</span><span class="Delimiter">)</span> &lt;&lt; <span class="Constant">&quot;storing &quot;</span> &lt;&lt; no_scientific<span class="Delimiter">(</span>value<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">))</span> &lt;&lt; <span class="Constant">&quot; in location &quot;</span> &lt;&lt; address+i &lt;&lt; end<span class="Delimiter">();</span>
+    put<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> address+i<span class="Delimiter">,</span> value<span class="Delimiter">.</span>at<span class="Delimiter">(</span>i<span class="Delimiter">));</span>
+  <span class="Delimiter">}</span>
+  <span class="Identifier">goto</span> finish_instruction<span class="Delimiter">;</span>
+<span class="Delimiter">}</span>
+
+<span class="Delimiter">:(scenario put_index_out_of_bounds)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  <span class="Constant">1</span>:array:point:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">7</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">8</span>:point<span class="Special"> &lt;- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
+  <span class="Constant">1</span>:array:point<span class="Special"> &lt;- </span>put-index <span class="Constant">1</span>:array:point<span class="Delimiter">,</span> <span class="Constant">4</span><span class="Delimiter">,</span> <span class="Constant">8</span>:point  <span class="Comment"># '4' is less than size of array in locations, but larger than its length in elements</span>
+]
+<span class="traceContains">+error: main: invalid index 4</span>
+
+<span class="Delimiter">:(scenario put_index_out_of_bounds_2)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  <span class="Constant">1</span>:array:point:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">6</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">7</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">8</span>:point<span class="Special"> &lt;- </span>merge <span class="Constant">34</span><span class="Delimiter">,</span> <span class="Constant">35</span>
+  <span class="Constant">1</span>:array:point<span class="Special"> &lt;- </span>put-index <span class="Constant">1</span>:array:point<span class="Delimiter">,</span> -<span class="Constant">1</span><span class="Delimiter">,</span> <span class="Constant">8</span>:point
+]
+<span class="traceContains">+error: main: invalid index -1</span>
+
+<span class="Delimiter">:(scenario put_index_product_error)</span>
+<span class="Special">% Hide_errors = true;</span>
+def main [
+  local-scope
+  load-ingredients
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">4</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>put-index <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Delimiter">,</span> <span class="Constant">0</span><span class="Delimiter">,</span> <span class="Constant">34</span>
+]
+<span class="traceContains">+error: main: product of 'put-index' must be first ingredient '1:array:number:3', but got '4:array:number:3'</span>
+
+<span class="SalientComment">//:: compute the length of an array</span>
+
+<span class="Delimiter">:(scenario array_length)</span>
+def main [
+  <span class="Constant">1</span>:array:number:<span class="Constant">3</span><span class="Special"> &lt;- </span>create-array
+  <span class="Constant">2</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">14</span>
+  <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">15</span>
+  <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>copy <span class="Constant">16</span>
+  <span class="Constant">5</span>:number<span class="Special"> &lt;- </span>length <span class="Constant">1</span>:array:number:<span class="Constant">3</span>
+]
+<span class="traceContains">+mem: storing 3 in location 5</span>
+
+<span class="Delimiter">:(before &quot;End Primitive Recipe Declarations&quot;)</span>
+LENGTH<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;length&quot;</span><span class="Delimiter">,</span> LENGTH<span class="Delimiter">);</span>
+<span class="Delimiter">:(before &quot;End Primitive Recipe Checks&quot;)</span>
+<span class="Normal">case</span> LENGTH: <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;'length' expects exactly 2 ingredients in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>inst<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>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> array = 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="Comment">// Update LENGTH array in Check</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>!is_mu_array<span class="Delimiter">(</span>array<span class="Delimiter">))</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; <span class="Constant">&quot;tried to calculate length of non-array '&quot;</span> &lt;&lt; array<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="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> LENGTH: <span class="Delimiter">{</span>
+  reagent<span class="Comment">/*</span><span class="Comment">copy</span><span class="Comment">*/</span> array = 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="Comment">// Update LENGTH array in Run</span>
+  <span class="Normal">if</span> <span class="Delimiter">(</span>array<span class="Delimiter">.</span>value == <span class="Constant">0</span><span class="Delimiter">)</span> <span class="Delimiter">{</span>
+    raise &lt;&lt; maybe<span class="Delimiter">(</span>current_recipe_name<span class="Delimiter">())</span> &lt;&lt; <span class="Constant">&quot;tried to access location 0 in '&quot;</span> &lt;&lt; to_original_string<span class="Delimiter">(</span>current_instruction<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>
+  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>get_or_insert<span class="Delimiter">(</span>Memory<span class="Delimiter">,</span> array<span class="Delimiter">.</span>value<span class="Delimiter">));</span>
+  <span class="Identifier">break</span><span class="Delimiter">;</span>
+<span class="Delimiter">}</span>
+
+<span class="Comment">//: optimization: none of the instructions in this layer use 'ingredients' so</span>
+<span class="Comment">//: stop copying potentially huge arrays into it.</span>
+<span class="Delimiter">:(before &quot;End should_copy_ingredients Special-cases&quot;)</span>
+recipe_ordinal r = current_instruction<span class="Delimiter">().</span>operation<span class="Delimiter">;</span>
+<span class="Normal">if</span> <span class="Delimiter">(</span>r == CREATE_ARRAY || r == INDEX || r == PUT_INDEX || r == LENGTH<span class="Delimiter">)</span>
+  <span class="Identifier">return</span> <span class="Constant">false</span><span class="Delimiter">;</span>
+</pre>
+</body>
+</html>
+<!-- vim: set foldmethod=manual : -->