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Implement Array#slice!

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okkez committed Mar 28, 2017
1 parent 6698049 commit 33f77fe3670b7a7c4ac8977d13d10256b58e862e
Showing with 100 additions and 0 deletions.
  1. +76 −0 mrbgems/mruby-array-ext/src/array.c
  2. +24 −0 mrbgems/mruby-array-ext/test/array.rb
@@ -149,6 +149,81 @@ mrb_ary_to_h(mrb_state *mrb, mrb_value ary)
return hash;
}
/*
* call-seq:
* ary.slice!(index) -> obj or nil
* ary.slice!(start, length) -> new_ary or nil
* ary.slice!(range) -> new_ary or nil
*
* Deletes the element(s) given by an +index+ (optionally up to +length+
* elements) or by a +range+.
*
* Returns the deleted object (or objects), or +nil+ if the +index+ is out of
* range.
*
* a = [ "a", "b", "c" ]
* a.slice!(1) #=> "b"
* a #=> ["a", "c"]
* a.slice!(-1) #=> "c"
* a #=> ["a"]
* a.slice!(100) #=> nil
* a #=> ["a"]
*/
static mrb_value
mrb_ary_slice_bang(mrb_state *mrb, mrb_value self)
{
struct RArray *a = mrb_ary_ptr(self);
mrb_int i, len;
mrb_value index;
mrb_value val;
mrb_value *ptr;
mrb_value ary;
mrb_ary_modify(mrb, a);
if (mrb_get_args(mrb, "o|i", &index, &len) == 1) {
switch (mrb_type(index)) {
case MRB_TT_RANGE:
if (mrb_range_beg_len(mrb, index, &i, &len, a->len, TRUE) == 1) {
goto delete_pos_len;
}
else {
return mrb_nil_value();
}
case MRB_TT_FIXNUM:
val = mrb_funcall(mrb, self, "delete_at", 1, index);
return val;
default:
val = mrb_funcall(mrb, self, "delete_at", 1, index);
return val;
}
}
i = mrb_fixnum(index);
delete_pos_len:
if (i < 0) i += a->len;
if (i < 0 || a->len < i) return mrb_nil_value();
if (len < 0) return mrb_nil_value();
if (a->len == i) return mrb_ary_new(mrb);
if (len > a->len - i) len = a->len - i;
ary = mrb_ary_new_capa(mrb, len);
for (mrb_int j = i, k = 0; k < len; ++j, ++k) {
mrb_ary_push(mrb, ary, a->ptr[j]);
}
ptr = a->ptr + i;
for (mrb_int j = i; j <= a->len - len; ++j) {
*ptr = *(ptr+len);
++ptr;
}
mrb_ary_resize(mrb, self, a->len - len);
return ary;
}
void
mrb_mruby_array_ext_gem_init(mrb_state* mrb)
{
@@ -159,6 +234,7 @@ mrb_mruby_array_ext_gem_init(mrb_state* mrb)
mrb_define_method(mrb, a, "rassoc", mrb_ary_rassoc, MRB_ARGS_REQ(1));
mrb_define_method(mrb, a, "values_at", mrb_ary_values_at, MRB_ARGS_ANY());
mrb_define_method(mrb, a, "to_h", mrb_ary_to_h, MRB_ARGS_REQ(0));
mrb_define_method(mrb, a, "slice!", mrb_ary_slice_bang, MRB_ARGS_ANY());
}
void
@@ -328,3 +328,27 @@ def to_ary
assert_nil(h.dig(2, 0))
assert_raise(TypeError) {h.dig(:a)}
end
assert("Array#slice!") do
a = [1, 2, 3]
b = a.slice!(0)
c = [1, 2, 3, 4, 5]
d = c.slice!(0, 2)
e = [1, 2, 3, 4, 5]
f = e.slice!(1..3)
g = [1, 2, 3]
h = g.slice!(-1)
i = [1, 2, 3]
j = i.slice!(0, -1)
assert_equal(a, [2, 3])
assert_equal(b, 1)
assert_equal(c, [3, 4, 5])
assert_equal(d, [1, 2])
assert_equal(e, [1, 5])
assert_equal(f, [2, 3, 4])
assert_equal(g, [1, 2])
assert_equal(h, 3)
assert_equal(i, [1, 2, 3])
assert_equal(j, nil)
end

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