Add test for grep() and wantarray

[p5sagit/p5-mst-13.2.git] / pod / perltrap.pod

diff --git a/pod/perltrap.pod b/pod/perltrap.pod
index 391c98b..4b56dd2 100644 (file)
--- a/pod/perltrap.pod
+++ b/pod/perltrap.pod
@@ -654,7 +654,8 @@ Formatted output and significant digits
 
 This specific item has been deleted.  It demonstrated how the auto-increment
 operator would not catch when a number went over the signed int limit.  Fixed
-in 5.003_04.  But always be wary when using large integers.  If in doubt:
+in version 5.003_04.  But always be wary when using large integers.
+If in doubt:
 
    use Math::BigInt;
 
@@ -663,10 +664,10 @@ in 5.003_04.  But always be wary when using large integers.  If in doubt:
 Assignment of return values from numeric equality tests
 does not work in perl5 when the test evaluates to false (0).
 Logical tests now return an null, instead of 0
- 
+
     $p = ($test == 1);
     print $p,"\n";
-  
+
     # perl4 prints: 0
     # perl5 prints:
 
@@ -934,7 +935,7 @@ of assignment.  Perl 4 mistakenly gave them the precedence of the associated
 operator.  So you now must parenthesize them in expressions like
 
     /foo/ ? ($a += 2) : ($a -= 2);
-    
+
 Otherwise
 
     /foo/ ? $a += 2 : $a -= 2
@@ -1107,6 +1108,26 @@ repeatedly, like C</x/> or C<m!x!>.
     # perl5 prints: perl5
 
 
+=item * Regular Expression
+
+Under perl4 and upto version 5.003, a failed C<m//g> match used to
+reset the internal iterator, so that subsequent C<m//g> match attempts
+began from the beginning of the string.  In perl version 5.004 and later,
+failed C<m//g> matches do not reset the iterator position (which can be
+found using the C<pos()> function--see L<perlfunc/pos>).
+
+    $test = "foop";
+    for (1..3) {
+        print $1 while ($test =~ /(o)/g);
+        # pos $test = 0;     # to get old behavior
+    }
+ 
+    # perl4     prints: oooooo
+    # perl5.004 prints: oo
+
+You may always reset the iterator yourself as shown in the commented line
+to get the old behavior.
+
 =back
 
 =head2 Subroutine, Signal, Sorting Traps
@@ -1164,7 +1185,7 @@ within  the signal handler function, each time a signal was handled with
 perl4.  With perl5, the reset is now done correctly.  Any code relying 
 on the handler _not_ being reset will have to be reworked.
 
-5.002 and beyond uses sigaction() under SysV
+Since version 5.002, Perl uses sigaction() under SysV.
 
     sub gotit {
         print "Got @_... ";