From 1d8320e1037855e9a90f987ec6649cc73247e60d Mon Sep 17 00:00:00 2001
From: Timo Paulssen <timonator@perpetuum-immobile.de>
Date: Thu, 13 Dec 2012 00:33:44 +0100
Subject: [PATCH] warn about obsolete use of . to concatenate strings.

---
 src/Perl6/Grammar.pm |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Perl6/Grammar.pm b/src/Perl6/Grammar.pm
index 6cd0123..f9a6e70 100644
--- a/src/Perl6/Grammar.pm
+++ b/src/Perl6/Grammar.pm
@@ -2896,7 +2896,7 @@ grammar Perl6::Grammar is HLL::Grammar does STD {
         | <?before <[ ' " ]> >
             [ <!{$*QSIGIL}> || <!before '"' <-["]>*? \s > ] # dwim on "$foo."
             <quote>
-            [ <?before '(' | '.(' | '\\'> || <.panic: "Quoted method name requires parenthesized arguments"> ]
+            [ <?before '(' | '.(' | '\\'> || <.panic: "Quoted method name requires parenthesized arguments. If you meant to concatenate two strings, use '~'."> ]
         ] <.unsp>?
         :dba('method arguments')
         [
@@ -3008,6 +3008,7 @@ grammar Perl6::Grammar is HLL::Grammar does STD {
     token infix:sym<xx>    { <sym> >> <O('%replication')> }
 
     token infix:sym<~>    { <sym>  <O('%concatenation')> }
+    token infix:sym<.>    { '.' <[\]\)\},:\s\$"']>  <.obs('. to concatenate strings', '~')> }
 
     token infix:sym<&>    { <sym> <O('%junctive_and')> }
     token infix:sym<|>    { <sym> <O('%junctive_or')> }
-- 
1.7.10.4