modify the type of return value (mrb_bool => mrb_value).

include/mruby.h

@@ -195,9 +195,9 @@ mrb_value mrb_funcall_with_block(mrb_state*, mrb_value, mrb_sym, int, mrb_value*
 mrb_sym mrb_intern_cstr(mrb_state*,const char*);
 mrb_sym mrb_intern2(mrb_state*,const char*,size_t);
 mrb_sym mrb_intern_str(mrb_state*,mrb_value);
-mrb_bool mrb_cstr_interned(mrb_state*,const char*);
-mrb_bool mrb_interned(mrb_state*,const char*,size_t);
-mrb_bool mrb_str_interned(mrb_state*,mrb_value);
+mrb_value mrb_cstr_interned(mrb_state*,const char*);
+mrb_value mrb_interned(mrb_state*,const char*,size_t);
+mrb_value mrb_str_interned(mrb_state*,mrb_value);
 const char *mrb_sym2name(mrb_state*,mrb_sym);
 const char *mrb_sym2name_len(mrb_state*,mrb_sym,size_t*);
 mrb_value mrb_sym2str(mrb_state*,mrb_sym);

src/symbol.c

@@ -72,25 +72,30 @@ mrb_intern_str(mrb_state *mrb, mrb_value str)
   return mrb_intern2(mrb, RSTRING_PTR(str), RSTRING_LEN(str));
 }
 
-mrb_bool
+mrb_value
 mrb_cstr_interned(mrb_state *mrb, const char *name)
 {
   return mrb_interned(mrb, name, strlen(name));
 }
 
-mrb_bool
+mrb_value
 mrb_interned(mrb_state *mrb, const char *name, size_t len)
 {
   khash_t(n2s) *h = mrb->name2sym;
   symbol_name sname;
+  khiter_t k;
 
   sname.len = len;
   sname.name = name;
 
-  return (kh_get(n2s, h, sname) != kh_end(h)) ? TRUE : FALSE;
+  k = kh_get(n2s, h, sname);
+  if (k != kh_end(h)) {
+    return mrb_symbol_value(kh_value(h, k));
+  }
+  return mrb_nil_value();
 }
 
-mrb_bool
+mrb_value
 mrb_str_interned(mrb_state *mrb, mrb_value str)
 {
   return mrb_interned(mrb, RSTRING_PTR(str), RSTRING_LEN(str));