Implement `Range#last` in `mruby-range-ext` in Ruby.

This reduce unnecessary calls of `mrb_funcall()`.
parent 76eafa46
......@@ -26,6 +26,32 @@ class Range
ary
end
##
# 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]
def last(*args)
raise RangeError, "cannot get the first element of beginless range" if self.end.nil?
return self.end if args.empty?
raise ArgumentError, "wrong number of arguments (given #{args.length}, expected 1)" unless args.length == 1
nv = args[0]
n = nv.__to_int
raise ArgumentError, "negative array size (or size too big)" unless 0 <= n
return self.to_a.last(nv)
end
def max(&block)
val = self.begin
last = self.end
......
......@@ -58,41 +58,6 @@ range_cover(mrb_state *mrb, mrb_value range)
return mrb_false_value();
}
/*
* 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
range_last(mrb_state *mrb, mrb_value range)
{
mrb_value num;
mrb_value array;
struct RRange *r = mrb_range_ptr(mrb, range);
if (mrb_nil_p(RANGE_END(r))) {
mrb_raise(mrb, E_RANGE_ERROR, "cannot get the last element of endless range");
}
if (mrb_get_args(mrb, "|o", &num) == 0) {
return mrb_range_end(mrb, range);
}
array = mrb_funcall_id(mrb, range, MRB_SYM(to_a), 0);
return mrb_funcall_id(mrb, array, MRB_SYM(last), 1, mrb_to_int(mrb, num));
}
/*
* call-seq:
* rng.size -> num
......@@ -194,7 +159,6 @@ mrb_mruby_range_ext_gem_init(mrb_state* mrb)
struct RClass * s = mrb_class_get(mrb, "Range");
mrb_define_method(mrb, s, "cover?", range_cover, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "last", range_last, MRB_ARGS_OPT(1));
mrb_define_method(mrb, s, "size", range_size, MRB_ARGS_NONE());
}
......
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