Merge pull request #2617 from suzukaze/add-kernel.Hash

Add Kernel#Hash

mrbgems/mruby-kernel-ext/src/kernel.c

 #include "mruby.h"
 #include "mruby/error.h"
 #include "mruby/array.h"
+#include "mruby/hash.h"
 
 /*
  *  call-seq:
@@ -75,6 +76,39 @@ mrb_f_array(mrb_state *mrb, mrb_value self)
   return tmp;
 }
 
+/*
+ *  call-seq:
+ *     Hash(arg)    -> hash
+ *
+ *  Converts <i>arg</i> to a <code>Hash</code> by calling
+ *  <i>arg</i><code>.to_hash</code>. Returns an empty <code>Hash</code> when
+ *  <i>arg</i> is <tt>nil</tt> or <tt>[]</tt>.
+ *
+ *     Hash([])          #=> {}
+ *     Hash(nil)         #=> {}
+ *     Hash(key: :value) #=> {:key => :value}
+ *     Hash([1, 2, 3])   #=> TypeError
+ */
+static mrb_value
+mrb_f_hash(mrb_state *mrb, mrb_value self)
+{
+  mrb_value arg, tmp;
+
+  mrb_get_args(mrb, "o", &arg);
+  if (mrb_nil_p(arg)) {
+    return mrb_hash_new(mrb);
+  }
+  tmp = mrb_check_convert_type(mrb, arg, MRB_TT_HASH, "Hash", "to_hash");
+  if (mrb_nil_p(tmp)) {
+    if (mrb_array_p(arg) && RARRAY_LEN(arg) == 0) {
+      return mrb_hash_new(mrb);
+    }
+    mrb_raisef(mrb, E_TYPE_ERROR, "can't convert %S into Hash",
+      mrb_str_new_cstr(mrb, mrb_obj_classname(mrb, arg)));
+  }
+  return tmp;
+}
+
 void
 mrb_mruby_kernel_ext_gem_init(mrb_state *mrb)
 {
@@ -84,6 +118,7 @@ mrb_mruby_kernel_ext_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, krn, "__method__", mrb_f_method, MRB_ARGS_NONE());
   mrb_define_module_function(mrb, krn, "String", mrb_f_string, MRB_ARGS_REQ(1));
   mrb_define_module_function(mrb, krn, "Array", mrb_f_array, MRB_ARGS_REQ(1));
+  mrb_define_module_function(mrb, krn, "Hash", mrb_f_hash, MRB_ARGS_REQ(1));
 }
 
 void

mrbgems/mruby-kernel-ext/test/kernel.rb

@@ -29,3 +29,10 @@ assert('Kernel#Array') do
   assert_equal([1, 2, 3, 4, 5], Kernel.Array(1..5))
   assert_equal([[:a, 1], [:b, 2], [:c, 3]], Kernel.Array({a:1, b:2, c:3}))
 end
+
+assert('Kernel#Hash') do
+  assert_equal({}, Hash([]))
+  assert_equal({}, Hash(nil))
+  assert_equal({:key => :value}, Hash(key: :value))
+  assert_raise(TypeError) { Hash([1, 2, 3]) }
+end