Changes between Version 41 and Version 42 of ExplicitCallStack

Timestamp:

01/30/07 08:36:53 (6 years ago)

Author:

guest

Comment:

--

ExplicitCallStack

@@ -93 +93 @@
                   False -> n * fac (n - 1)
 }}}
+
+People probably don't write code like this very much, but nonetheless, it does expose some of the issues we must deal with.
 
 Here is a basic term-reduction for the program:
@@ -109 +111 @@
 By the time that `hd` is called on the empty list, the only thing remaining on the dynamic evaluation stack is `print`.
 
-The question is what stack would you "like" to see in this case?
+The question is what stack would you ''like'' to see in this case?
+
+One option is this:
+{{{
+   main -> d -> e -> f -> hd
+}}}
+
+Another option is this:
+{{{
+   main -> d -> hd
+}}}
+
+The difference between these two stacks is how we determine ''when'' `hd` is called. Is it in the context where `hd` is first mentioned by name (in the body of `f`), or is it when `hd` becomes fully saturated (in the body of `d`). Both contexts seem reasonable. Does it really matter which one is chosen? At the moment I can't say for sure.
+
+There are more possibilities, for instance, we treat CAFs as roots of the stack, thus dropping `main` and `d` from the first of the options above:
+{{{
+   e -> f -> hd
+}}}
+
+And so on.
+
+
 
 == Transformation rules ==