Add s///r (non-destructive substitution).

[p5sagit/p5-mst-13.2.git] / op.c

diff --git a/op.c b/op.c
index 47f8300..40ef4bc 100644 (file)
--- a/op.c
+++ b/op.c
@@ -1110,6 +1110,11 @@ Perl_scalarvoid(pTHX_ OP *o)
        useless = "negative pattern binding (!~)";
        break;
 
+    case OP_SUBST:
+       if (cPMOPo->op_pmflags & PMf_NONDESTRUCT)
+           useless = "Non-destructive substitution (s///r)";
+       break;
+
     case OP_RV2GV:
     case OP_RV2SV:
     case OP_RV2AV:
@@ -2225,6 +2230,11 @@ Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
        no_bareword_allowed(right);
     }
 
+    /* !~ doesn't make sense with s///r, so error on it for now */
+    if (rtype == OP_SUBST && (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT) &&
+       type == OP_NOT)
+       yyerror("Using !~ with s///r doesn't make sense");
+
     ismatchop = rtype == OP_MATCH ||
                rtype == OP_SUBST ||
                rtype == OP_TRANS;
@@ -2238,7 +2248,9 @@ Perl_bind_match(pTHX_ I32 type, OP *left, OP *right)
        right->op_flags |= OPf_STACKED;
        if (rtype != OP_MATCH &&
             ! (rtype == OP_TRANS &&
-               right->op_private & OPpTRANS_IDENTICAL))
+               right->op_private & OPpTRANS_IDENTICAL) &&
+           ! (rtype == OP_SUBST &&
+              (cPMOPx(right)->op_pmflags & PMf_NONDESTRUCT)))
            newleft = mod(left, rtype);
        else
            newleft = left;