From: nobu.nokada@...
Date: 2005-09-17T09:16:34+09:00
Subject: Re: proposed attr writer patch

Hi,

At Sat, 17 Sep 2005 05:01:16 +0900,
Daniel Berger wrote in [ruby-core:05796]:
> IIRC, this would also fix the issue with "?" and "!" in struct members 
> (but I may be remembering incorrectly).
> 
> BTW, Evan Webb has already added this patch to Sydney.

It doesn't work.

  $ ./ruby -e 'class X;attr_accessor :foo?; end; x=X.new; x.foo=1; p x.foo?'
  -e:1:in `attr_accessor': invalid attribute name `foo?' (NameError)
  	from -e:1

And:

+       sprintf(buf, "%s=", name);

buf and name point same area here, but I'm not sure if this
behavior is guaranteed.


Index: eval.c
===================================================================
RCS file: /cvs/ruby/src/ruby/eval.c,v
retrieving revision 1.831
diff -U2 -p -r1.831 eval.c
--- eval.c	14 Sep 2005 08:30:15 -0000	1.831
+++ eval.c	17 Sep 2005 00:14:25 -0000
@@ -624,5 +624,5 @@ rb_attr(VALUE klass, ID id, int read, in
     const char *name;
     char *buf;
-    ID attriv;
+    ID attriv, rid = id;
     int noex;
     size_t len;
@@ -644,17 +644,22 @@ rb_attr(VALUE klass, ID id, int read, in
     }
 
-    if (!rb_is_local_id(id) && !rb_is_const_id(id)) {
-	rb_name_error(id, "invalid attribute name `%s'", rb_id2name(id));
-    }
     name = rb_id2name(id);
     if (!name) {
 	rb_raise(rb_eArgError, "argument needs to be symbol or string");
     }
-    len = strlen(name)+2;
-    buf = ALLOCA_N(char,len);
-    snprintf(buf, len, "@%s", name);
+    len = strlen(name);
+    buf = ALLOCA_N(char,len+2);
+    snprintf(buf, len+2, "@%s", name);
+    if (name[len-1] == '?' || name[len-1] == '!') {
+	buf[len--] = 0;
+	id = rb_intern(buf+1);
+    }
+    if (!rb_is_local_id(id) && !rb_is_const_id(id)) {
+	rb_name_error(id, "invalid attribute name `%s'", rb_id2name(id));
+    }
+
     attriv = rb_intern(buf);
     if (read) {
-	rb_add_method(klass, id, NEW_IVAR(attriv), noex);
+	rb_add_method(klass, rid, NEW_IVAR(attriv), noex);
     }
     if (write) {


-- 
Nobu Nakada