Define Struct#deconstruct_keys

1 files changed, 28 insertions, 0 deletions

diff --git a/struct.c b/struct.c
index 273c719aec..f4ae094f00 100644
--- a/struct.c
+++ b/struct.c
@@ -944,6 +944,33 @@ rb_struct_to_h(VALUE s)
     return h;
 }
 
+static VALUE
+rb_struct_deconstruct_keys(VALUE s, VALUE keys)
+{
+    VALUE h;
+    long i;
+
+    if (NIL_P(keys)) {
+        return rb_struct_to_h(s);
+    }
+    if (UNLIKELY(!RB_TYPE_P(keys, T_ARRAY))) {
+	rb_raise(rb_eTypeError,
+                 "wrong argument type %"PRIsVALUE" (expected Array or nil)",
+                 rb_obj_class(keys));
+
+    }
+    h = rb_hash_new_with_size(RARRAY_LEN(keys));
+    for (i=0; i<RARRAY_LEN(keys); i++) {
+        VALUE key = RARRAY_AREF(keys, i);
+        int i = rb_struct_pos(s, &key);
+        if (i < 0) {
+            return rb_hash_new_with_size(0);
+        }
+        rb_hash_aset(h, key, RSTRUCT_GET(s, i));
+    }
+    return h;
+}
+
 /* :nodoc: */
 VALUE
 rb_struct_init_copy(VALUE copy, VALUE s)
@@ -1357,6 +1384,7 @@ InitVM_Struct(void)
     rb_define_method(rb_cStruct, "dig", rb_struct_dig, -1);
 
     rb_define_method(rb_cStruct, "deconstruct", rb_struct_to_a, 0);
+    rb_define_method(rb_cStruct, "deconstruct_keys", rb_struct_deconstruct_keys, 1);
 }
 
 #undef rb_intern