diff options
Diffstat (limited to 'src/array.c')
| -rw-r--r-- | src/array.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/src/array.c b/src/array.c index 8ab30bd8e..e83f7e2d8 100644 --- a/src/array.c +++ b/src/array.c @@ -578,6 +578,47 @@ mrb_ary_shift(mrb_state *mrb, mrb_value self) return val; } +MRB_API mrb_value +mrb_ary_shift_m(mrb_state *mrb, mrb_value self) +{ + struct RArray *a = mrb_ary_ptr(self); + mrb_int len = ARY_LEN(a); + mrb_int n; + mrb_value val; + + if (mrb_get_args(mrb, "|i", &n) == 0) { + return mrb_ary_shift(mrb, self); + }; + ary_modify_check(mrb, a); + if (len == 0 || n == 0) return mrb_ary_new(mrb); + if (n > len) n = len; + val = mrb_ary_new_from_values(mrb, n, ARY_PTR(a)); + if (ARY_SHARED_P(a)) { + L_SHIFT: + a->as.heap.ptr+=n; + a->as.heap.len-=n; + return val; + } + if (len > ARY_SHIFT_SHARED_MIN) { + ary_make_shared(mrb, a); + goto L_SHIFT; + } + else if (len == n) { + ARY_SET_LEN(a, 0); + } + else { + mrb_value *ptr = ARY_PTR(a); + mrb_int size = len-n; + + while (size--) { + *ptr = *(ptr+n); + ++ptr; + } + ARY_SET_LEN(a, len-n); + } + return val; +} + /* self = [1,2,3] item = 0 self.unshift item @@ -1318,7 +1359,7 @@ mrb_init_array(mrb_state *mrb) mrb_define_method(mrb, a, "reverse", mrb_ary_reverse, MRB_ARGS_NONE()); /* 15.2.12.5.24 */ mrb_define_method(mrb, a, "reverse!", mrb_ary_reverse_bang, MRB_ARGS_NONE()); /* 15.2.12.5.25 */ mrb_define_method(mrb, a, "rindex", mrb_ary_rindex_m, MRB_ARGS_REQ(1)); /* 15.2.12.5.26 */ - mrb_define_method(mrb, a, "shift", mrb_ary_shift, MRB_ARGS_NONE()); /* 15.2.12.5.27 */ + mrb_define_method(mrb, a, "shift", mrb_ary_shift_m, MRB_ARGS_OPT(1)); /* 15.2.12.5.27 */ mrb_define_method(mrb, a, "size", mrb_ary_size, MRB_ARGS_NONE()); /* 15.2.12.5.28 */ mrb_define_method(mrb, a, "slice", mrb_ary_aget, MRB_ARGS_ARG(1,1)); /* 15.2.12.5.29 */ mrb_define_method(mrb, a, "unshift", mrb_ary_unshift_m, MRB_ARGS_ANY()); /* 15.2.12.5.30 */ |