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author | Prajjwal Singh <sin@prajjwal.com> | 2019-10-07 10:42:29 +0530 |
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committer | Nobuyoshi Nakada <nobu@ruby-lang.org> | 2019-10-07 15:59:12 +0900 |
commit | c8542ab484efb6ee0009cd081789d9a68f482483 (patch) | |
tree | f8c00b416b4ff3c7fae2cb534338162066201b17 | |
parent | d4ec37f69e3bd6f88725fe1075daa2e5f58c2aec (diff) | |
download | ruby-c8542ab484efb6ee0009cd081789d9a68f482483.tar.gz |
Add: Array#intersection method
-rw-r--r-- | NEWS | 6 | ||||
-rw-r--r-- | array.c | 31 | ||||
-rw-r--r-- | test/ruby/test_array.rb | 17 |
3 files changed, 54 insertions, 0 deletions
@@ -129,6 +129,12 @@ sufficient information, see the ChangeLog file or Redmine === Core classes updates (outstanding ones only) +Array:: + + New method:: + + * Added Array#intersection. [Feature #16155] + Complex:: New method:: @@ -4668,6 +4668,36 @@ rb_ary_and(VALUE ary1, VALUE ary2) return ary3; } +/* + * call-seq: + * ary.intersection(other_ary1, other_ary2, ...) -> new_ary + * + * Set Intersection --- Returns a new array containing unique elements common + * to +self+ and <code>other_ary</code>s. Order is preserved from the original + * array. + * + * It compares elements using their #hash and #eql? methods for efficiency. + * + * [ 1, 1, 3, 5 ].intersection([ 3, 2, 1 ]) # => [ 1, 3 ] + * [ "a", "b", "z" ].intersection([ "a", "b", "c" ], [ "b" ]) # => [ "b" ] + * [ "a" ].intersection #=> [ "a" ] + * + * See also Array#&. + */ + +static VALUE +rb_ary_intersection_multi(int argc, VALUE *argv, VALUE ary) +{ + VALUE result = rb_ary_dup(ary); + int i; + + for (i = 0; i < argc; i++) { + result = rb_ary_and(result, argv[i]); + } + + return result; +} + static int ary_hash_orset(st_data_t *key, st_data_t *value, st_data_t arg, int existing) { @@ -6928,6 +6958,7 @@ Init_Array(void) rb_define_method(rb_cArray, "concat", rb_ary_concat_multi, -1); rb_define_method(rb_cArray, "union", rb_ary_union_multi, -1); rb_define_method(rb_cArray, "difference", rb_ary_difference_multi, -1); + rb_define_method(rb_cArray, "intersection", rb_ary_intersection_multi, -1); rb_define_method(rb_cArray, "<<", rb_ary_push, 1); rb_define_method(rb_cArray, "push", rb_ary_push_m, -1); rb_define_alias(rb_cArray, "append", "push"); diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb index 955a00ad99..6d730db4ae 100644 --- a/test/ruby/test_array.rb +++ b/test/ruby/test_array.rb @@ -241,6 +241,23 @@ class TestArray < Test::Unit::TestCase assert_equal(@cls[], @cls[ 1, 2, 3 ]*64 & @cls[ 4, 5, 6 ]*64) end + def test_intersection + assert_equal(@cls[1, 2], @cls[1, 2, 3].intersection(@cls[1, 2])) + assert_equal(@cls[ ], @cls[1].intersection(@cls[ ])) + assert_equal(@cls[ ], @cls[ ].intersection(@cls[1])) + assert_equal(@cls[1], @cls[1, 2, 3].intersection(@cls[1, 2], @cls[1])) + assert_equal(@cls[ ], @cls[1, 2, 3].intersection(@cls[1, 2], @cls[3])) + assert_equal(@cls[ ], @cls[1, 2, 3].intersection(@cls[4, 5, 6])) + end + + def test_intersection_big_array + assert_equal(@cls[1, 2], (@cls[1, 2, 3] * 64).intersection(@cls[1, 2] * 64)) + assert_equal(@cls[ ], (@cls[1] * 64).intersection(@cls[ ])) + assert_equal(@cls[ ], @cls[ ].intersection(@cls[1] * 64)) + assert_equal(@cls[1], (@cls[1, 2, 3] * 64).intersection((@cls[1, 2] * 64), (@cls[1] * 64))) + assert_equal(@cls[ ], (@cls[1, 2, 3] * 64).intersection(@cls[4, 5, 6] * 64)) + end + def test_MUL # '*' assert_equal(@cls[], @cls[]*3) assert_equal(@cls[1, 1, 1], @cls[1]*3) |