From a10e023e280a942393a96816c96bae288a77f9d4 Mon Sep 17 00:00:00 2001
From: James E Keenan <[email protected]>
Date: Sat, 13 Sep 2014 08:51:48 -0400
Subject: [PATCH] Semicolon before ellipsis inside block disambiguates.

Correct documentation which indicated that, inside a block, a semicolon after
an ellipsis statement would disambiguate between a block and a hash reference
constructor.  The semicolon must precede the ellipsis to perform this
disambiguation.

Add tests to demonstrate that whitespace around the ellipsis statement does
not impeded the disambiguation.

For: RT #122661
---
 pod/perlsyn.pod | 11 +++++------
 t/op/yadayada.t | 31 ++++++++++++++++++++++++++++---
 2 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/pod/perlsyn.pod b/pod/perlsyn.pod
index cea4d50..73421a4 100644
--- a/pod/perlsyn.pod
+++ b/pod/perlsyn.pod
@@ -788,14 +788,13 @@ syntax error if Perl doesn't guess that the C<{ ... }> is a block.  In that
 case, it doesn't think the C<...> is an ellipsis because it's expecting an
 expression instead of a statement:
 
-    @transformed = map { ... } @input;  # syntax error
+    @transformed = map { ... } @input;    # syntax error
 
-You can use a C<;> inside your block to denote that the C<{ ...  }> is a
-block and not a hash reference constructor.  Now the ellipsis works:
+Inside your block, you can use a C<;> before the ellipsis to denote that the
+C<{ ... }> is a block and not a hash reference constructor.  Now the ellipsis
+works:
 
-    @transformed = map {; ... } @input; # ; disambiguates
-
-    @transformed = map { ...; } @input; # ; disambiguates
+    @transformed = map {; ... } @input;   # ';' disambiguates
 
 Note: Some folks colloquially refer to this bit of punctuation as a
 "yada-yada" or "triple-dot", but its true name
diff --git a/t/op/yadayada.t b/t/op/yadayada.t
index 770a51e..a213bec 100644
--- a/t/op/yadayada.t
+++ b/t/op/yadayada.t
@@ -8,14 +8,39 @@ BEGIN {
 
 use strict;
 
-plan 5;
+plan 9;
 
-my $err = "Unimplemented at $0 line " . ( __LINE__ + 2 ) . ".\n";
+my $err;
+my $err1 = "Unimplemented at $0 line ";
+my $err2 = ".\n";
 
+$err = $err1 . ( __LINE__ + 1 ) . $err2;
 eval { ... };
+is $@, $err, "Execution of ellipsis statement reported 'Unimplemented' code";
+$@ = '';
 
-is $@, $err;
+note("RT #122661: Semicolon before ellipsis statement disambiguates to indicate block rather than hash reference");
+my @input = (3..5);
+my @transformed;
+$err = $err1 . ( __LINE__ + 1 ) . $err2;
+eval { @transformed = map {; ... } @input; };
+is $@, $err, "Disambiguation case 1";
+$@ = '';
 
+$err = $err1 . ( __LINE__ + 1 ) . $err2;
+eval { @transformed = map {;...} @input; };
+is $@, $err, "Disambiguation case 2";
+$@ = '';
+
+$err = $err1 . ( __LINE__ + 1 ) . $err2;
+eval { @transformed = map {; ...} @input; };
+is $@, $err, "Disambiguation case 3";
+$@ = '';
+
+$err = $err1 . ( __LINE__ + 1 ) . $err2;
+eval { @transformed = map {;... } @input; };
+is $@, $err, "Disambiguation case 4";
+$@ = '';
 
 #
 # Regression tests, making sure ... is still parsable as an operator.
-- 
1.9.1