Implement Struct#values_at and Array#values_at .

Add API `mrb_get_values_at()` to mruby/range.h .

2 files changed, 26 insertions, 0 deletions

diff --git a/mrbgems/mruby-struct/src/struct.c b/mrbgems/mruby-struct/src/struct.c
index a4d70ae1a..40ad88aca 100644
--- a/mrbgems/mruby-struct/src/struct.c
+++ b/mrbgems/mruby-struct/src/struct.c
@@ -12,6 +12,7 @@
 #include "mruby/class.h"
 #include "mruby/variable.h"
 #include "mruby/hash.h"
+#include "mruby/range.h"
 
 #define RSTRUCT_LEN(st) RARRAY_LEN(st)
 #define RSTRUCT_PTR(st) RARRAY_PTR(st)
@@ -828,6 +829,23 @@ mrb_struct_to_h(mrb_state *mrb, mrb_value self)
   return ret;
 }
 
+static mrb_value
+struct_values_at_getter(mrb_state *mrb, mrb_value self, mrb_int idx)
+{
+  return mrb_struct_aref_n(mrb, self, mrb_fixnum_value(idx));
+}
+
+static mrb_value
+mrb_struct_values_at(mrb_state *mrb, mrb_value self)
+{
+  mrb_int argc;
+  mrb_value *argv;
+
+  mrb_get_args(mrb, "*", &argv, &argc);
+
+  return mrb_get_values_at(mrb, self, MRB_INT_MAX, argc, argv, struct_values_at_getter);
+}
+
 /*
  *  A <code>Struct</code> is a convenient way to bundle a number of
  *  attributes together, using accessor methods, without having to write
@@ -866,6 +884,7 @@ mrb_mruby_struct_gem_init(mrb_state* mrb)
   mrb_define_method(mrb, st,        "to_a",           mrb_struct_to_a,        MRB_ARGS_NONE());
   mrb_define_method(mrb, st,        "values",         mrb_struct_to_a,        MRB_ARGS_NONE());
   mrb_define_method(mrb, st,        "to_h",           mrb_struct_to_h,        MRB_ARGS_NONE());
+  mrb_define_method(mrb, st,        "values_at",      mrb_struct_values_at,   MRB_ARGS_NONE());
 }
 
 void
diff --git a/mrbgems/mruby-struct/test/struct.rb b/mrbgems/mruby-struct/test/struct.rb
index d654830ca..b3b9ce33f 100644
--- a/mrbgems/mruby-struct/test/struct.rb
+++ b/mrbgems/mruby-struct/test/struct.rb
@@ -123,3 +123,10 @@ assert('Struct#to_h') do
   s = Struct.new(:white, :red, :green).new('ruuko', 'yuzuki', 'hitoe')
   assert_equal(:white => 'ruuko', :red => 'yuzuki', :green => 'hitoe') { s.to_h }
 end
+
+assert('Struct#values_at') do
+  a = Struct.new(:blue, :purple).new('aki', 'io')
+  assert_equal ['aki'], a.values_at(0)
+  assert_equal ['io', 'aki'], a.values_at(1, 0)
+  assert_raise(IndexError) { a.values_at 2 }
+end