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authornobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-10-05 06:23:34 (GMT)
committernobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-10-05 06:23:34 (GMT)
commitd65d5533ab117b46211917450293f9c602519375 (patch)
treed604080f517ef921d2f74a64991524692092b662 /array.c
parent68bf34fc272bea7df6a1aeb60096d362df9e5a22 (diff)
Add difference method to Array
I introduce a `difference` method equivalent to the `-` operator, but which accept more than array as argument. This improved readability, and it is also coherent with the `+` operator, which has a similar `concat` method. The method doesn't modify the original object and return a new object instead. I plan to introduce a `difference!` method as well. Tests and documentation are included. It solves partially https://bugs.ruby-lang.org/issues/14097 From: Ana María Martínez Gómez <ammartinez@suse.de> git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64921 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'array.c')
-rw-r--r--array.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/array.c b/array.c
index 7aeec16..8a1eed7 100644
--- a/array.c
+++ b/array.c
@@ -4190,6 +4190,8 @@ ary_recycle_hash(VALUE hash)
* [ 1, 1, 2, 2, 3, 3, 4, 5 ] - [ 1, 2, 4 ] #=> [ 3, 3, 5 ]
*
* If you need set-like behavior, see the library class Set.
+ *
+ * See Array#difference.
*/
static VALUE
@@ -4222,6 +4224,63 @@ rb_ary_diff(VALUE ary1, VALUE ary2)
/*
* call-seq:
+ * ary.difference(other_ary1, other_ary2,...) -> ary
+ *
+ * Array Difference
+ *
+ * Returns a new array that is a copy of +self+, removing any items
+ * that also appear in any of the +other_ary+s. The order of +self+ is
+ * preserved.
+ *
+ * It compares elements using their #hash and #eql? methods for efficiency.
+ *
+ * [ 1, 1, 2, 2, 3, 3, 4, 5 ].difference([ 1, 2, 4 ]) #=> [ 3, 3, 5 ]
+ * [ 1, 'c', :s, 'yep' ].difference([ 1 ], [ 'a', 'c' ]) #=> [:s, "yep"]
+ *
+ * If you need set-like behavior, see the library class Set.
+ *
+ * See Array#-.
+ */
+
+static VALUE
+rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
+{
+ VALUE ary_diff;
+ long i, length;
+ volatile VALUE t0;
+ bool *is_hash = ALLOCV_N(bool, t0, argc);
+ ary_diff = rb_ary_new();
+ length = RARRAY_LEN(ary);
+
+ for (i = 0; i < argc; i++) {
+ argv[i] = to_ary(argv[i]);
+ is_hash[i] = (length > SMALL_ARRAY_LEN && RARRAY_LEN(argv[i]) > SMALL_ARRAY_LEN);
+ if (is_hash[i]) argv[i] = ary_make_hash(argv[i]);
+ }
+
+ for (i = 0; i < RARRAY_LEN(ary); i++) {
+ int j;
+ VALUE elt = rb_ary_elt(ary, i);
+ for (j = 0; j < argc; j++){
+ if (is_hash[j]) {
+ if (st_lookup(rb_hash_tbl_raw(argv[j]), RARRAY_AREF(ary, i), 0))
+ break;
+ }
+ else {
+ if (rb_ary_includes_by_eql(argv[j], elt)) break;
+ }
+ }
+ if (j == argc) rb_ary_push(ary_diff, elt);
+ }
+
+ ALLOCV_END(t0);
+
+ return ary_diff;
+}
+
+
+/*
+ * call-seq:
* ary & other_ary -> new_ary
*
* Set Intersection --- Returns a new array containing unique elements common to the
@@ -6363,6 +6422,7 @@ Init_Array(void)
rb_define_method(rb_cArray, "last", rb_ary_last, -1);
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, "<<", rb_ary_push, 1);
rb_define_method(rb_cArray, "push", rb_ary_push_m, -1);
rb_define_alias(rb_cArray, "append", "push");