Added rb_hash_lookup2()

This is basically rb_hash_lookup() except it returns a custom default
value instead of Qnil.

spec/ruby/optional/capi/ext/hash_spec.c

@@ -86,6 +86,12 @@ VALUE hash_spec_rb_hash_lookup_nil(VALUE self, VALUE hash, VALUE key) {
 }
 #endif
 
+#ifdef HAVE_RB_HASH_LOOKUP2
+VALUE hash_spec_rb_hash_lookup2(VALUE self, VALUE hash, VALUE key, VALUE def) {
+  return rb_hash_lookup2(hash, key, def);
+}
+#endif
+
 #ifdef HAVE_RB_HASH_NEW
 VALUE hash_spec_rb_hash_new(VALUE self) {
   return rb_hash_new();
@@ -135,6 +141,10 @@ void Init_hash_spec() {
   rb_define_method(cls, "rb_hash_lookup", hash_spec_rb_hash_lookup, 2);
 #endif
 
+#ifdef HAVE_RB_HASH_LOOKUP2
+  rb_define_method(cls, "rb_hash_lookup2", hash_spec_rb_hash_lookup2, 3);
+#endif
+
 #ifdef HAVE_RB_HASH_NEW
   rb_define_method(cls, "rb_hash_new", hash_spec_rb_hash_new, 0);
 #endif

spec/ruby/optional/capi/ext/rubyspec.h

@@ -324,6 +324,7 @@
 #define HAVE_RB_HASH_DELETE_IF             1
 #define HAVE_RB_HASH_FOREACH               1
 #define HAVE_RB_HASH_LOOKUP                1
+#define HAVE_RB_HASH_LOOKUP2               1
 #define HAVE_RB_HASH_NEW                   1
 #define HAVE_RB_HASH_SIZE                  1
 

spec/ruby/optional/capi/hash_spec.rb

@@ -153,5 +153,19 @@
         @s.rb_hash_lookup_nil(hsh, :chunky).should be_true
       end
     end
+
+    describe "rb_hash_lookup2" do
+      it "returns the value associated with the key" do
+        hash = {:chunky => 'bacon'}
+
+        @s.rb_hash_lookup2(hash, :chunky, nil).should == 'bacon'
+      end
+
+      it "returns the default value if the key does not exist" do
+        hash = {}
+
+        @s.rb_hash_lookup2(hash, :chunky, 10).should == 10
+      end
+    end
   end
 end

vm/capi/hash.cpp

@@ -35,11 +35,16 @@ extern "C" {
   }
 
   VALUE rb_hash_lookup(VALUE self, VALUE key) {
-    VALUE entry = capi_fast_call(self, rb_intern("find_item"), 1, key);
+    return rb_hash_lookup2(self, key, Qnil);
+  }
+
+  VALUE rb_hash_lookup2(VALUE hash, VALUE key, VALUE def) {
+    VALUE entry = capi_fast_call(hash, rb_intern("find_item"), 1, key);
+
     if(entry != Qnil) {
       return capi_fast_call(entry, rb_intern("value"), 0);
     } else {
-      return Qnil;
+      return def;
     }
   }
 

vm/include/capi/ruby/ruby.h

@@ -1434,6 +1434,8 @@ struct RTypedData {
   /** Return the value associated with the key, excluding default values. */
   VALUE   rb_hash_lookup(VALUE self, VALUE key);
 
+  VALUE   rb_hash_lookup2(VALUE hash, VALUE key, VALUE def);
+
   /** Set the value associated with the key. */
   VALUE   rb_hash_aset(VALUE self, VALUE key, VALUE value);