Add a new #filter alias for #select

* In Enumerable, Enumerator::Lazy, Array, Hash and Set
  [Feature #13784] [ruby-core:82285]
* Share specs for the various #select#select! methods and
  reuse them for #filter/#filter!.
* Add corresponding filter tests for select tests.
* Update NEWS.

[Fix GH-1824]

From: Alexander Patrick <adp90@case.edu>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62575 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/hash.c b/hash.c
index d2ca057e33..3a499872ad 100644
--- a/hash.c
+++ b/hash.c
@@ -4690,6 +4690,8 @@ Init_Hash(void)
     rb_define_method(rb_cHash, "keep_if", rb_hash_keep_if, 0);
     rb_define_method(rb_cHash, "select", rb_hash_select, 0);
     rb_define_method(rb_cHash, "select!", rb_hash_select_bang, 0);
+    rb_define_method(rb_cHash, "filter", rb_hash_select, 0);
+    rb_define_method(rb_cHash, "filter!", rb_hash_select_bang, 0);
     rb_define_method(rb_cHash, "reject", rb_hash_reject, 0);
     rb_define_method(rb_cHash, "reject!", rb_hash_reject_bang, 0);
     rb_define_method(rb_cHash, "slice", rb_hash_slice, -1);
@@ -4752,6 +4754,8 @@ Init_Hash(void)
     rb_define_singleton_method(envtbl, "reject!", env_reject_bang, 0);
     rb_define_singleton_method(envtbl, "select", env_select, 0);
     rb_define_singleton_method(envtbl, "select!", env_select_bang, 0);
+    rb_define_singleton_method(envtbl, "filter", env_select, 0);
+    rb_define_singleton_method(envtbl, "filter!", env_select_bang, 0);
     rb_define_singleton_method(envtbl, "shift", env_shift, 0);
     rb_define_singleton_method(envtbl, "invert", env_invert, 0);
     rb_define_singleton_method(envtbl, "replace", env_replace, 1);