From: Yusuke ENDOH <mame@...>
Date: 2009-11-04T12:50:12+09:00
Subject: [ruby-core:26522] Re: HashWithIndifferentAccess to core

Hi,

2009/11/4 "Martin J. Durst" <duerst@it.aoyama.ac.jp>:
> Just a thought: What about implementing this with an option on Hash:new,
> rather than as a separate class? That at least would solve the problem with
> the class name.

This sounds good if HWIA is really imported.

How about "Hash#compare_as_string_key" following in
"Hash#compare_by_indentity"?


  h = {}
  h.compare_as_string_key

  h[:a] = :foo
  h["b"] = :bar

  p h["a"] #=> :foo
  p h[:b]  #=> :bar
  p h      #=> {:a=>:foo, "b"=>:bar}

  h[1] = 1 #=> neither string nor symbol key in strhash (RuntimeError)
           #   (should it be assumed as "1" by using to_s?)


Here is a patch (I didn't refer the original patch, sorry):


diff --git a/hash.c b/hash.c
index ef8b9a8..e26312c 100644
--- a/hash.c
+++ b/hash.c
@@ -99,6 +99,44 @@ rb_any_hash(VALUE a)
     return (st_index_t)RSHIFT(hnum, 1);
 }

+static int
+rb_strsym_cmp(VALUE a, VALUE b)
+{
+    if (a == b) return 0;
+    switch (TYPE(a)) {
+      case T_SYMBOL:
+	a = rb_id2str(SYM2ID(a));
+      case T_STRING:
+	switch (TYPE(b)) {
+	  case T_SYMBOL:
+	    b = rb_id2str(SYM2ID(b));
+	  case T_STRING:
+	    return rb_str_hash_cmp(a, b);
+	}
+    }
+    rb_raise(rb_eRuntimeError, "not string nor symbol key in strhash");
+}
+
+static st_index_t
+rb_strsym_hash(VALUE a)
+{
+    VALUE hval;
+    st_index_t hnum;
+
+    switch (TYPE(a)) {
+      case T_SYMBOL:
+	a = rb_id2str(SYM2ID(a));
+      case T_STRING:
+	hnum = rb_str_hash(a);
+	break;
+
+      default:
+	rb_raise(rb_eRuntimeError, "neither string nor symbol key in strhash");
+    }
+    hnum <<= 1;
+    return (st_index_t)RSHIFT(hnum, 1);
+}
+
 static const struct st_hash_type objhash = {
     rb_any_cmp,
     rb_any_hash,
@@ -109,6 +147,11 @@ static const struct st_hash_type identhash = {
     st_numhash,
 };

+static const struct st_hash_type strsymhash = {
+    rb_strsym_cmp,
+    rb_strsym_hash,
+};
+
 typedef int st_foreach_func(st_data_t, st_data_t, st_data_t);

 struct foreach_safe_arg {
@@ -1852,6 +1895,40 @@ rb_hash_compare_by_id_p(VALUE hash)
     return Qfalse;
 }

+/*
+ *  call-seq:
+ *    hsh.compare_as_string_key => hsh
+ *
+ *  TBD
+ */
+
+static VALUE
+rb_hash_compare_as_string_key(VALUE hash)
+{
+    rb_hash_modify(hash);
+    RHASH(hash)->ntbl->type = &strsymhash;
+    rb_hash_rehash(hash);
+    return hash;
+}
+
+/*
+ *  call-seq:
+ *    hsh.compare_as_string_key? => true or false
+ *
+ *  TBD
+ */
+
+static VALUE
+rb_hash_compare_as_string_key_p(VALUE hash)
+{
+    if (!RHASH(hash)->ntbl)
+        return Qfalse;
+    if (RHASH(hash)->ntbl->type == &strsymhash) {
+	return Qtrue;
+    }
+    return Qfalse;
+}
+
 static int path_tainted = -1;

 static char **origenviron;
@@ -2715,6 +2792,8 @@ Init_Hash(void)

     rb_define_method(rb_cHash,"compare_by_identity", rb_hash_compare_by_id, 0);
     rb_define_method(rb_cHash,"compare_by_identity?",
rb_hash_compare_by_id_p, 0);
+    rb_define_method(rb_cHash,"compare_as_string_key",
rb_hash_compare_as_string_key, 0);
+    rb_define_method(rb_cHash,"compare_as_string_key?",
rb_hash_compare_as_string_key_p, 0);

     origenviron = environ;
     envtbl = rb_obj_alloc(rb_cObject);

-- 
Yusuke ENDOH <mame@tsg.ne.jp>