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author | mrkn <mrkn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-07-14 06:44:00 +0000 |
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committer | mrkn <mrkn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2017-07-14 06:44:00 +0000 |
commit | 1405111722af070f443e32d31d96177dac21b782 (patch) | |
tree | 676151764f3753acba21e2dd6114c2a8a3de33f9 /hash.c | |
parent | 0b396d588060707e227f21b80e964180674c8a50 (diff) | |
download | ruby-1405111722af070f443e32d31d96177dac21b782.tar.gz |
hash.c: Add Hash#transform_keys and Hash#transform_keys!
* hash.c (transform_keys_i, rb_hash_transform_keys): Add Hash#transform_keys.
[Feature #13583] [ruby-core:81290]
* hash.c (rb_hash_transform_keys_bang): Add Hash#transform_keys!.
[Feature #13583] [ruby-core:81290]
* test/ruby/test_hash.rb: Add tests for above changes.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59328 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'hash.c')
-rw-r--r-- | hash.c | 74 |
1 files changed, 74 insertions, 0 deletions
@@ -1825,6 +1825,78 @@ rb_hash_each_pair(VALUE hash) } static int +transform_keys_i(VALUE key, VALUE value, VALUE result) +{ + VALUE new_key = rb_yield(key); + rb_hash_aset(result, new_key, value); + return ST_CONTINUE; +} + +/* + * call-seq: + * hsh.transform_keys {|key| block } -> new_hash + * hsh.transform_keys -> an_enumerator + * + * Returns a new hash with the results of running the block once for + * every key. + * This method does not change the values. + * + * h = { a: 1, b: 2, c: 3 } + * h.transform_keys {|k| k.to_s } #=> { "a" => 1, "b" => 2, "c" => 3 } + * h.transform_keys(&:to_s) #=> { "a" => 1, "b" => 2, "c" => 3 } + * h.transform_keys.with_index {|k, i| "#{k}.#{i}" } + * #=> { "a.0" => 1, "b.1" => 2, "c.2" => 3 } + * + * If no block is given, an enumerator is returned instead. + */ +static VALUE +rb_hash_transform_keys(VALUE hash) +{ + VALUE result; + + RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size); + result = rb_hash_new(); + if (!RHASH_EMPTY_P(hash)) { + rb_hash_foreach(hash, transform_keys_i, result); + } + + return result; +} + +/* + * call-seq: + * hsh.transform_keys! {|value| block } -> hsh + * hsh.transform_keys! -> an_enumerator + * + * Invokes the given block once for each key in <i>hsh</i>, replacing it + * with the new key returned by the block, and then returns <i>hsh</i>. + * This method does not change the values. + * + * h = { a: 1, b: 2, c: 3 } + * h.transform_keys! {|k| k.to_s } #=> { "a" => 1, "b" => 2, "c" => 3 } + * h.transform_keys!(&:to_sym) #=> { a: 1, b: 2, c: 3 } + * h.transform_keys!.with_index {|k, i| "#{k}.#{i}" } + * #=> { "a.0" => 1, "b.1" => 2, "c.2" => 3 } + * + * If no block is given, an enumerator is returned instead. + */ +static VALUE +rb_hash_transform_keys_bang(VALUE hash) +{ + RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size); + rb_hash_modify_check(hash); + if (RHASH(hash)->ntbl) { + long i; + VALUE keys = rb_hash_keys(hash); + for (i = 0; i < RARRAY_LEN(keys); ++i) { + VALUE new_key = rb_yield(RARRAY_AREF(keys, i)); + rb_hash_aset(hash, new_key, rb_hash_delete(hash, RARRAY_AREF(keys, i))); + } + } + return hash; +} + +static int transform_values_i(VALUE key, VALUE value, VALUE result) { VALUE new_value = rb_yield(value); @@ -4507,6 +4579,8 @@ Init_Hash(void) rb_define_method(rb_cHash, "each_pair", rb_hash_each_pair, 0); rb_define_method(rb_cHash, "each", rb_hash_each_pair, 0); + rb_define_method(rb_cHash, "transform_keys", rb_hash_transform_keys, 0); + rb_define_method(rb_cHash, "transform_keys!", rb_hash_transform_keys_bang, 0); rb_define_method(rb_cHash, "transform_values", rb_hash_transform_values, 0); rb_define_method(rb_cHash, "transform_values!", rb_hash_transform_values_bang, 0); |