4112

2 files changed, 18 insertions, 26 deletions

diff --git a/continuation4.mu b/continuation4.mu
index 5957c1be..26f72bf4 100644
--- a/continuation4.mu
+++ b/continuation4.mu
@@ -21,19 +21,15 @@ def create-yielder l:&:list:num -> n:num, done?:bool [
   load-ingredients
   {
     done? <- equal l, 0
-    # Our current primitives can lead to gnarly code to ensure that we always
-    # statically match a continuation call with a 'return-continuation-until-mark'.
-    # Try to design functions to either always return or always return continuation.
-    {
-      # should we have conditional versions of return-continuation-until-mark
-      # analogous to return-if and return-unless? Names get really long.
-      break-unless done?
-      return-continuation-until-mark 0, done?
-      return 0, done?  # just a guard rail; should never execute
-    }
+    break-if done?
     n <- first l
     l <- rest l
     return-continuation-until-mark n, done?
     loop
   }
+  # A function that returns continuations shouldn't get the opportunity to
+  # return. Calling functions should stop calling its continuation after this
+  # point.
+  return-continuation-until-mark -1, done?
+  assert 0/false, [called too many times, ran out of continuations to return]
 ]
diff --git a/html/continuation4.mu.html b/html/continuation4.mu.html
index d827031e..546a5533 100644
--- a/html/continuation4.mu.html
+++ b/html/continuation4.mu.html
@@ -81,22 +81,18 @@ if ('onhashchange' in window) {
 <span id="L21" class="LineNr">21 </span>  <span class="Constant">load-ingredients</span>
 <span id="L22" class="LineNr">22 </span>  <span class="Delimiter">{</span>
 <span id="L23" class="LineNr">23 </span>  <span class="Conceal">¦</span> done? <span class="Special">&lt;-</span> equal l,<span class="Constant"> 0</span>
-<span id="L24" class="LineNr">24 </span>  <span class="Conceal">¦</span> <span class="Comment"># Our current primitives can lead to gnarly code to ensure that we always</span>
-<span id="L25" class="LineNr">25 </span>  <span class="Conceal">¦</span> <span class="Comment"># statically match a continuation call with a 'return-continuation-until-mark'.</span>
-<span id="L26" class="LineNr">26 </span>  <span class="Conceal">¦</span> <span class="Comment"># Try to design functions to either always return or always return continuation.</span>
-<span id="L27" class="LineNr">27 </span>  <span class="Conceal">¦</span> <span class="Delimiter">{</span>
-<span id="L28" class="LineNr">28 </span>  <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Comment"># should we have conditional versions of return-continuation-until-mark</span>
-<span id="L29" class="LineNr">29 </span>  <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="Comment"># analogous to return-if and return-unless? Names get really long.</span>
-<span id="L30" class="LineNr">30 </span>  <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">break-unless</span> done?
-<span id="L31" class="LineNr">31 </span>  <span class="Conceal">¦</span> <span class="Conceal">¦</span> return-continuation-until-mark<span class="Constant"> 0</span>, done?
-<span id="L32" class="LineNr">32 </span>  <span class="Conceal">¦</span> <span class="Conceal">¦</span> <span class="muControl">return</span><span class="Constant"> 0</span>, done?  <span class="Comment"># just a guard rail; should never execute</span>
-<span id="L33" class="LineNr">33 </span>  <span class="Conceal">¦</span> <span class="Delimiter">}</span>
-<span id="L34" class="LineNr">34 </span>  <span class="Conceal">¦</span> n <span class="Special">&lt;-</span> first l
-<span id="L35" class="LineNr">35 </span>  <span class="Conceal">¦</span> l <span class="Special">&lt;-</span> <a href='064list.mu.html#L24'>rest</a> l
-<span id="L36" class="LineNr">36 </span>  <span class="Conceal">¦</span> return-continuation-until-mark n, done?
-<span id="L37" class="LineNr">37 </span>  <span class="Conceal">¦</span> <span class="muControl">loop</span>
-<span id="L38" class="LineNr">38 </span>  <span class="Delimiter">}</span>
-<span id="L39" class="LineNr">39 </span>]
+<span id="L24" class="LineNr">24 </span>  <span class="Conceal">¦</span> <span class="muControl">break-if</span> done?
+<span id="L25" class="LineNr">25 </span>  <span class="Conceal">¦</span> n <span class="Special">&lt;-</span> first l
+<span id="L26" class="LineNr">26 </span>  <span class="Conceal">¦</span> l <span class="Special">&lt;-</span> <a href='064list.mu.html#L24'>rest</a> l
+<span id="L27" class="LineNr">27 </span>  <span class="Conceal">¦</span> return-continuation-until-mark n, done?
+<span id="L28" class="LineNr">28 </span>  <span class="Conceal">¦</span> <span class="muControl">loop</span>
+<span id="L29" class="LineNr">29 </span>  <span class="Delimiter">}</span>
+<span id="L30" class="LineNr">30 </span>  <span class="Comment"># A function that returns continuations shouldn't get the opportunity to</span>
+<span id="L31" class="LineNr">31 </span>  <span class="Comment"># return. Calling functions should stop calling its continuation after this</span>
+<span id="L32" class="LineNr">32 </span>  <span class="Comment"># point.</span>
+<span id="L33" class="LineNr">33 </span>  return-continuation-until-mark<span class="Constant"> -1</span>, done?
+<span id="L34" class="LineNr">34 </span>  assert <span class="Constant">0/false</span>, <span class="Constant">[called too many times, ran out of continuations to return]</span>
+<span id="L35" class="LineNr">35 </span>]
 </pre>
 </body>
 </html>