Document and test $; prototype syntax

This has worked this way for yonks.  It is actually useful, so it might
as well be documented.

diff --git a/pod/perlsub.pod b/pod/perlsub.pod
index d344c47..e2a9bcf 100644 (file)
--- a/pod/perlsub.pod
+++ b/pod/perlsub.pod
@@ -1149,7 +1149,11 @@ arguments, just like C<time()>.  That is, if you say
     mytime +2;
 
 you'll get C<mytime() + 2>, not C<mytime(2)>, which is how it would be parsed
-without a prototype.
+without a prototype.  If you want to force a unary function to have the
+same precedence as a list operator, add C<;> to the end of the prototype:
+
+    sub mygetprotobynumber($;);
+    mygetprotobynumber $a > $b; # parsed as mygetprotobynumber($a > $b)
 
 The interesting thing about C<&> is that you can generate new syntax with it,
 provided it's in the initial position:

diff --git a/t/comp/proto.t b/t/comp/proto.t
index 50aebef..2394164 100644 (file)
--- a/t/comp/proto.t
+++ b/t/comp/proto.t
@@ -18,7 +18,7 @@ BEGIN {
 # strict
 use strict;
 
-print "1..174\n";
+print "1..177\n";
 
 my $i = 1;
 
@@ -700,6 +700,17 @@ print "not "
  unless eval 'sub uniproto9 (;+) {} uniproto9 $_, 1' or warn $@;
 print "ok ", $i++, "\n";
 
+# Test that a trailing semicolon makes a sub have listop precedence
+sub unilist ($;)  { $_[0]+1 }
+sub unilist2(_;)  { $_[0]+1 }
+sub unilist3(;$;) { $_[0]+1 }
+print "not " unless (unilist 0 || 5) == 6;
+print "ok ", $i++, "\n";
+print "not " unless (unilist2 0 || 5) == 6;
+print "ok ", $i++, "\n";
+print "not " unless (unilist3 0 || 5) == 6;
+print "ok ", $i++, "\n";
+
 {
   # Lack of prototype on a subroutine definition should override any prototype
   # on the declaration.