add nil.to_a, nil.to_f, nil.to_i methods

mrbgems/default.gembox

@@ -41,6 +41,9 @@ MRuby::GemBox.new do |conf|
   # Use Random class
   conf.gem :core => "mruby-random"
 
+  # Use extensional Object class
+  conf.gem :core => "mruby-object-ext"
+
   # Use ObjectSpace class
   conf.gem :core => "mruby-objectspace"
 

mrbgems/mruby-object-ext/mrbgem.rake

@@ -0,0 +1,4 @@
+MRuby::Gem::Specification.new('mruby-object-ext') do |spec|
+  spec.license = 'MIT'
+  spec.authors = 'mruby developers'
+end

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

@@ -0,0 +1,56 @@
+#include "mruby.h"
+#include "mruby/array.h"
+
+/*
+ *  call-seq:
+ *     nil.to_a    -> []
+ *
+ *  Always returns an empty array.
+ */
+
+static mrb_value
+nil_to_a(mrb_state *mrb, mrb_value obj)
+{
+    return mrb_ary_new(mrb);
+}
+
+/*
+ *  call-seq:
+ *     nil.to_f    -> 0.0
+ *
+ *  Always returns zero.
+ */
+
+static mrb_value
+nil_to_f(mrb_state *mrb, mrb_value obj)
+{
+    return mrb_float_value(mrb, 0.0);
+}
+
+/*
+ *  call-seq:
+ *     nil.to_i    -> 0
+ *
+ *  Always returns zero.
+ */
+
+static mrb_value
+nil_to_i(mrb_state *mrb, mrb_value obj)
+{
+    return mrb_fixnum_value(0);
+}
+
+void
+mrb_mruby_object_ext_gem_init(mrb_state* mrb)
+{
+  struct RClass * n = mrb->nil_class;
+
+  mrb_define_method(mrb, n, "to_a", nil_to_a,       MRB_ARGS_NONE());
+  mrb_define_method(mrb, n, "to_f", nil_to_f,       MRB_ARGS_NONE());
+  mrb_define_method(mrb, n, "to_i", nil_to_i,       MRB_ARGS_NONE());
+}
+
+void
+mrb_mruby_object_ext_gem_final(mrb_state* mrb)
+{
+}

mrbgems/mruby-object-ext/test/nil.rb

@@ -0,0 +1,11 @@
+assert('NilClass#to_a') do
+  assert_equal nil.to_a, []
+end
+
+assert('NilClass#to_f') do
+  assert_equal nil.to_f, 0.0
+end
+
+assert('NilClass#to_i') do
+  assert_equal nil.to_i, 0
+end

src/object.c

@@ -5,6 +5,7 @@
 */
 
 #include "mruby.h"
+#include "mruby/array.h"
 #include "mruby/class.h"
 #include "mruby/numeric.h"
 #include "mruby/string.h"

test/t/nil.rb

@@ -27,4 +27,3 @@ end
 assert('NilClass#to_s', '15.2.4.3.5') do
   assert_equal nil.to_s, ''
 end
-