From: Daniel Berger <Daniel.Berger@...>
Date: 2005-09-17T05:01:16+09:00
Subject: proposed attr writer patch

Hi all,

Currently, if you do something like this:

attr_accessor :foo?, :bar!

You end up with "bar!=", "foo?=", "bar!", and "foo?".  The problem is 
that "bar!=" and "foo?=" are both pointless and syntactically invalid. 
Wouldn't it be better if accessors followed the DWIM approach so that we 
end up with something both useful and syntactically valid?

Below is a patch so that attr_accessor handles "?" and "!" better (IMO), 
so that, using my original example, you end up with "bar=", "bar!", 
"foo=", "foo?".

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.

Regards,

Dan

PS - The diff is against 1.8.3p2

--- eval.orig   Fri Sep 16 13:46:40 2005
+++ eval.c      Fri Sep 16 13:47:59 2005
@@ -680,15 +680,25 @@
      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);
+
+/* Detect ? and ! endings */
+    len = strlen(name);
+    buf = ALLOCA_N(char,len+2);
+    sprintf(buf, "@%s", name);
+
+    if(name[len-1] == '?' || name[len-1] == '!') {
+        buf[len] = 0; /* remove the last character */
+        name = buf + 1; /* reassign name so if write is set, it uses the
+                           short var name */
+    }
      attriv = rb_intern(buf);
      if (read) {
         rb_add_method(klass, id, NEW_IVAR(attriv), noex);
      }
      if (write) {
-       rb_add_method(klass, rb_id_attrset(id), NEW_ATTRSET(attriv), noex);
+       sprintf(buf, "%s=", name);
+       id = rb_intern(buf);
+       rb_add_method(klass, id, NEW_ATTRSET(attriv), noex);
      }
  }