Deprecate ?PATTERN? without explicit m operator

Deprecate ?PATTERN?, recommending the equivalent m?PATTERN? syntax, in
order to eventually allow the question mark to be used in new operators
that would currently be ambiguous.

(With minor reconciliation edits by David Golden)

Signed-off-by: David Golden <dagolden@cpan.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/toke.c b/toke.c
index 70b1dfdf4e..584aea0247 100644
--- a/toke.c
+++ b/toke.c
@@ -5993,6 +5993,8 @@ Perl_yylex(pTHX)
 	          || isALNUM_lazy_if(PL_last_uni+5,UTF)
 	      ))
 	         check_uni();
+	     if (*s == '?')
+		 deprecate("?PATTERN? without explicit operator");
 	     s = scan_pat(s,OP_MATCH);
 	     TERM(sublex_start());
 	 }