1 files changed, 141 insertions, 0 deletions
diff --git a/mrbgems/mruby-range-ext/src/range.c b/mrbgems/mruby-range-ext/src/range.c
new file mode 100644
index 000000000..fe615776f
--- /dev/null
+++ b/mrbgems/mruby-range-ext/src/range.c
@@ -0,0 +1,141 @@
+#include "mruby.h"
+#include "mruby/range.h"
+
+static int
+r_le(mrb_state *mrb, mrb_value a, mrb_value b)
+{
+  mrb_value r = mrb_funcall(mrb, a, "<=>", 1, b); /* compare result */
+  /* output :a < b => -1, a = b =>  0, a > b => +1 */
+
+  if (mrb_type(r) == MRB_TT_FIXNUM) {
+    mrb_int c = mrb_fixnum(r);
+    if (c == 0 || c == -1) return TRUE;
+  }
+
+  return FALSE;
+}
+
+static int
+r_lt(mrb_state *mrb, mrb_value a, mrb_value b)
+{
+  mrb_value r = mrb_funcall(mrb, a, "<=>", 1, b);
+  /* output :a < b => -1, a = b =>  0, a > b => +1 */
+
+  if (mrb_type(r) == MRB_TT_FIXNUM) {
+    if (mrb_fixnum(r) == -1) return TRUE;
+  }
+
+  return FALSE;
+}
+
+/*
+ *  call-seq:
+ *     rng.cover?(obj)  ->  true or false
+ *
+ *  Returns <code>true</code> if +obj+ is between the begin and end of
+ *  the range.
+ *
+ *  This tests <code>begin <= obj <= end</code> when #exclude_end? is +false+
+ *  and <code>begin <= obj < end</code> when #exclude_end? is +true+.
+ *
+ *     ("a".."z").cover?("c")    #=> true
+ *     ("a".."z").cover?("5")    #=> false
+ *     ("a".."z").cover?("cc")   #=> true
+ */
+static mrb_value
+mrb_range_cover(mrb_state *mrb, mrb_value range)
+{
+  mrb_value val;
+  struct RRange *r = mrb_range_ptr(range);
+  mrb_value beg, end;
+
+  mrb_get_args(mrb, "o", &val);
+
+  beg = r->edges->beg;
+  end = r->edges->end;
+
+  if (r_le(mrb, beg, val)) {
+    if (r->excl) {
+      if (r_lt(mrb, val, end))
+        return mrb_true_value();
+    }
+    else {
+      if (r_le(mrb, val, end))
+        return mrb_true_value();
+    }
+  }
+
+  return mrb_false_value();
+}
+
+/*
+ *  call-seq:
+ *     rng.first    -> obj
+ *     rng.first(n) -> an_array
+ *
+ *  Returns the first object in the range, or an array of the first +n+
+ *  elements.
+ *
+ *    (10..20).first     #=> 10
+ *    (10..20).first(3)  #=> [10, 11, 12]
+ */
+static mrb_value
+mrb_range_first(mrb_state *mrb, mrb_value range)
+{
+  mrb_value num;
+  mrb_value array;
+  struct RRange *r = mrb_range_ptr(range);
+
+  if (mrb_get_args(mrb, "|o", &num) == 0) {
+    return r->edges->beg;
+  }
+
+  array = mrb_funcall(mrb, range, "to_a", 0);
+  return mrb_funcall(mrb, array, "first", 1, mrb_to_int(mrb, num));
+}
+
+/*
+ *  call-seq:
+ *     rng.last    -> obj
+ *     rng.last(n) -> an_array
+ *
+ *  Returns the last object in the range,
+ *  or an array of the last +n+ elements.
+ *
+ *  Note that with no arguments +last+ will return the object that defines
+ *  the end of the range even if #exclude_end? is +true+.
+ *
+ *    (10..20).last      #=> 20
+ *    (10...20).last     #=> 20
+ *    (10..20).last(3)   #=> [18, 19, 20]
+ *    (10...20).last(3)  #=> [17, 18, 19]
+ */
+static mrb_value
+mrb_range_last(mrb_state *mrb, mrb_value range)
+{
+  mrb_value num;
+  mrb_value array;
+  struct RRange *r = mrb_range_ptr(range);
+
+  if (mrb_get_args(mrb, "|o", &num) == 0) {
+    return r->edges->end;
+  }
+
+  array = mrb_funcall(mrb, range, "to_a", 0);
+  return mrb_funcall(mrb, array, "last", 1, mrb_to_int(mrb, num));
+}
+
+void
+mrb_mruby_range_ext_gem_init(mrb_state* mrb)
+{
+  struct RClass * s = mrb_class_get(mrb, "Range");
+
+  mrb_define_method(mrb, s, "cover?",          mrb_range_cover,         ARGS_REQ(1));
+  mrb_define_method(mrb, s, "first",           mrb_range_first,         ARGS_OPT(1));
+  mrb_define_method(mrb, s, "last",            mrb_range_last,          ARGS_OPT(1));
+}
+
+void
+mrb_mruby_range_ext_gem_final(mrb_state* mrb)
+{
+}