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* array.c (rb_ary_resize): new utility function. [ruby-dev:42912]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30465 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This commit is contained in:
nobu 2011-01-05 20:10:59 +00:00
parent 697a45b196
commit c8aaf31fdd
5 changed files with 90 additions and 0 deletions

45
array.c
View file

@ -1308,6 +1308,51 @@ rb_ary_splice(VALUE ary, long beg, long len, VALUE rpl)
}
}
/*!
* expands or shrinks \a ary to \a len elements.
* expanded region will be filled with Qnil.
* \param ary an arrray
* \param len new size
* \return \a ary
* \post the size of \a ary is \a len.
*/
VALUE
rb_ary_resize(VALUE ary, long len)
{
long olen;
rb_ary_modify(ary);
olen = RARRAY_LEN(ary);
if (len == olen) return ary;
if (len > ARY_MAX_SIZE) {
rb_raise(rb_eIndexError, "index %ld too big", len);
}
if (len > olen) {
if (len >= ARY_CAPA(ary)) {
ary_double_capa(ary, len);
}
rb_mem_clear(RARRAY_PTR(ary) + olen, len - olen);
ARY_SET_HEAP_LEN(ary, len);
}
else if (ARY_EMBED_P(ary)) {
ARY_SET_EMBED_LEN(ary, len);
}
else if (len <= RARRAY_EMBED_LEN_MAX) {
VALUE tmp[RARRAY_EMBED_LEN_MAX];
MEMCPY(tmp, ARY_HEAP_PTR(ary), VALUE, len);
ary_discard(ary);
MEMCPY(ARY_EMBED_PTR(ary), tmp, VALUE, len);
ARY_SET_EMBED_LEN(ary, len);
}
else {
if (olen > len + ARY_DEFAULT_SIZE) {
REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, len);
}
ARY_SET_HEAP_LEN(ary, len);
}
return ary;
}
/*
* call-seq:
* ary[index] = obj -> obj

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@ -0,0 +1 @@
create_makefile("-test-/array/resize")

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@ -0,0 +1,14 @@
#include "ruby/ruby.h"
static VALUE
ary_resize(VALUE ary, VALUE len)
{
rb_ary_resize(ary, NUM2LONG(len));
return ary;
}
void
Init_resize(void)
{
rb_define_method(rb_cArray, "resize", ary_resize, 1);
}

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@ -83,6 +83,7 @@ VALUE rb_ary_includes(VALUE, VALUE);
VALUE rb_ary_cmp(VALUE, VALUE);
VALUE rb_ary_replace(VALUE copy, VALUE orig);
VALUE rb_get_values_at(VALUE, long, int, VALUE*, VALUE(*)(VALUE,long));
VALUE rb_ary_resize(VALUE ary, long len);
/* bignum.c */
VALUE rb_big_new(long, int);
int rb_bigzero_p(VALUE x);

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@ -0,0 +1,29 @@
require 'test/unit'
require '-test-/array/resize'
class TestArray < Test::Unit::TestCase
class TestResize < Test::Unit::TestCase
def test_expand
feature = '[ruby-dev:42912]'
ary = [*1..10]
ary.resize(10)
assert_equal(10, ary.size, feature)
assert_equal([*1..10], ary, feature)
ary.resize(100)
assert_equal(100, ary.size, feature)
assert_equal([*1..10]+[nil]*90, ary, feature)
ary.resize(20)
assert_equal(20, ary.size, feature)
assert_equal([*1..10]+[nil]*10, ary, feature)
ary.resize(2)
assert_equal(2, ary.size, feature)
assert_equal([1,2], ary, feature)
ary.resize(3)
assert_equal(3, ary.size, feature)
assert_equal([1,2,nil], ary, feature)
ary.resize(10)
assert_equal(10, ary.size, feature)
assert_equal([1,2]+[nil]*8, ary, feature)
end
end
end