added Symbol#[]

git-svn-id: http://svn.macosforge.org/repository/ruby/MacRuby/branches/icu@3743 23306eb0-4c56-4727-a40e-e92c0eb68959

encoding.h

@@ -291,6 +291,7 @@ str_set_valid_encoding(rb_str_t *self, bool status)
 
 VALUE mr_enc_s_is_compatible(VALUE klass, SEL sel, VALUE str1, VALUE str2);
 VALUE rb_str_intern_fast(VALUE str);
+VALUE rstr_aref(VALUE str, SEL sel, int argc, VALUE *argv);
 
 // The following functions should always been prefered over anything else,
 // especially if this "else" is RSTRING_PTR and RSTRING_LEN.

string.c

@@ -1640,7 +1640,7 @@ rb_str_subpat(VALUE str, VALUE re, int nth)
     return Qnil;
 }
 
-static VALUE
+VALUE
 rstr_aref(VALUE str, SEL sel, int argc, VALUE *argv)
 {
     if (argc == 2) {

symbol.c

@@ -607,6 +607,20 @@ rsym_empty(VALUE sym, SEL sel)
     return rb_str_chars_len(RSYM(sym)->str) == 0 ? Qtrue : Qfalse;
 }
 
+/*
+ * call-seq:
+ *   sym[idx]      => char
+ *   sym[b, n]     => char
+ *
+ * Returns <code>sym.to_s[]</code>.
+ */
+
+static VALUE
+rsym_aref(VALUE sym, SEL sel, int argc, VALUE *argv)
+{
+    return rstr_aref(RSYM(sym)->str, sel, argc, argv);
+}
+
 static CFIndex
 rsym_imp_length(void *rcv, SEL sel)
 {
@@ -643,6 +657,7 @@ Init_Symbol(void)
     rb_objc_define_method(rb_cSymbol, "intern", rsym_to_sym, 0);
     rb_objc_define_method(rb_cSymbol, "to_sym", rsym_to_sym, 0);
     rb_objc_define_method(rb_cSymbol, "empty?", rsym_empty, 0);
+    rb_objc_define_method(rb_cSymbol, "[]", rsym_aref, -1);
 
     // Cocoa primitives.
     rb_objc_install_method2((Class)rb_cSymbol, "length",