From: Rafael Garcia-Suarez <rgarciasuarez@gmail.com>
Date: Sun, 24 May 2009 21:51:42 +0000 (+0200)
Subject: Allow ~~ overloading on the left side, when the right side is a plain scalar
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=2c9d2554ad3b3d37d1c8b83cf0f3c4b4b99fde8b;p=p5sagit%2Fp5-mst-13.2.git

Allow ~~ overloading on the left side, when the right side is a plain scalar
---

diff --git a/pod/perlsyn.pod b/pod/perlsyn.pod
index 4302cf4..20ec68e 100644
--- a/pod/perlsyn.pod
+++ b/pod/perlsyn.pod
@@ -717,6 +717,7 @@ and "Array" entries apply in those cases. (For blessed references, the
     Array   Regex     array grep               grep /$b/, @$a
     Any     Regex     pattern match            $a =~ /$b/
 
+    Object  Any       invokes ~~ overloading on $object, or falls back:
     Any     Num       numeric equality         $a == $b
     Num     numish[4] numeric equality         $a == $b
     Any     Any       string equality          $a eq $b
diff --git a/pp_ctl.c b/pp_ctl.c
index e12b671..5adfc68 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -4001,6 +4001,7 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
     SV *e = TOPs;	/* e is for 'expression' */
     SV *d = TOPm1s;	/* d is for 'default', as in PL_defgv */
 
+    /* First of all, handle overload magic of the rightmost argument */
     if (SvAMAGIC(e)) {
 	SV * const tmpsv = amagic_call(d, e, smart_amg, 0);
 	if (tmpsv) {
@@ -4371,9 +4372,25 @@ S_do_smartmatch(pTHX_ HV *seen_this, HV *seen_other)
 	    RETURN;
 	}
     }
-    /* ~~ X..Y TODO */
     /* ~~ scalar */
-    else if (SvNIOK(e) || (SvPOK(e) && looks_like_number(e) && SvNIOK(d))) {
+    /* See if there is overload magic on left */
+    else if (object_on_left && SvAMAGIC(d)) {
+	SV *tmpsv;
+	PUSHs(d); PUSHs(e);
+	PUTBACK;
+	tmpsv = amagic_call(d, e, smart_amg, AMGf_noright);
+	if (tmpsv) {
+	    SPAGAIN;
+	    (void)POPs;
+	    SETs(tmpsv);
+	    RETURN;
+	}
+	SP -= 2;
+	goto sm_any_scalar;
+    }
+    else
+  sm_any_scalar:
+    if (SvNIOK(e) || (SvPOK(e) && looks_like_number(e) && SvNIOK(d))) {
 	/* numeric comparison */
 	PUSHs(d); PUSHs(e);
 	PUTBACK;
diff --git a/t/op/smartmatch.t b/t/op/smartmatch.t
index 5dfebbd..8c48768 100644
--- a/t/op/smartmatch.t
+++ b/t/op/smartmatch.t
@@ -37,7 +37,15 @@ tie my %tied_hash, 'Tie::StdHash';
 {
     package Test::Object::WithOverload;
     sub new { bless { key => 'magic' } }
-    use overload '~~' => sub { my %hash = %{ $_[0] }; $_[1] eq $hash{key} };
+    use overload '~~' => sub {
+	my %hash = %{ $_[0] };
+	if ($_[2]) { # arguments reversed ?
+	    return $_[1] eq reverse $hash{key};
+	}
+	else {
+	    return $_[1] eq $hash{key};
+	}
+    };
     use overload '""' => sub { "stringified" };
     use overload 'eq' => sub {"$_[0]" eq "$_[1]"};
 }
@@ -158,15 +166,15 @@ __DATA__
 
 # Any ~~ object overloaded
 !	\&fatal		$ov_obj
-	'magic'		$ov_obj
-!	'not magic'	$ov_obj
+	'cigam'		$ov_obj
+!	'cigam on'	$ov_obj
 !	$obj		$ov_obj
 !	undef		$ov_obj
 
 # regular object
 @	$obj		$obj
 @	$ov_obj		$obj
-@	\&fatal		$obj
+=@	\&fatal		$obj
 @	\&FALSE		$obj
 @	\&foo		$obj
 @	sub { 1 }	$obj
@@ -183,7 +191,9 @@ __DATA__
 # object (overloaded or not) ~~ Any
 	$obj		qr/NoOverload/
 	$ov_obj		qr/^stringified$/
-	$ov_obj		"stringified"
+	"$ov_obj"	"stringified"
+	$ov_obj		'magic'
+!	$ov_obj		'not magic'
 
 # ~~ Coderef
 	sub{0}		sub { ref $_[0] eq "CODE" }