RT #126159, notes on IterationEnd

Raku · Sep 28, 2015 · 5fc7cbd · 5fc7cbd
1 parent 645466d
commit 5fc7cbd
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/lib/Type/Iterator.pod b/lib/Type/Iterator.pod
@@ -16,11 +16,15 @@ Iterators generally only allow one iteration over the sequence; afterwards
 they are exhausted.
 
 The main API is the C<pull-one> method, which either returns the next value,
-or the special value C<IterationEnd> if no more elements are available. Each
+or the sentinel value C<IterationEnd> if no more elements are available. Each
 class implementing C<Iterator> must provide a C<pull-one> method. All other
 Iterator API methods can be implemented in terms of C<pull-one>, but also
 overriden for performance reasons.
 
+Note: The only valid use of the sentinel value C<IterationEnd> in a program
+is identity comparison (using C<=:=>) with the result of a method in the
+iterator API. Any other behavior is undefined and implementation dependent.
+
 =head1 Methods
 
 =head2 method pull-one