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author | mame <mame@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2008-03-17 13:28:46 +0000 |
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committer | mame <mame@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2008-03-17 13:28:46 +0000 |
commit | 89afc5431b10e20689bcaac33a9e81a12d1b2b95 (patch) | |
tree | fcff3a675f88b5e65a8fcac6884866943dfe1b7e /array.c | |
parent | c97735b53c8b1c9f76543c9d802dde097b0f4e7a (diff) | |
download | ruby-89afc5431b10e20689bcaac33a9e81a12d1b2b95.tar.gz |
* array.c (rb_ary_take, rb_ary_take_while, rb_ary_drop,
rb_ary_drop_while): new method. [ruby-dev:34067]
* test/ruby/test_array.rb: add tests for above.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@15791 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'array.c')
-rw-r--r-- | array.c | 95 |
1 files changed, 95 insertions, 0 deletions
@@ -3228,6 +3228,96 @@ rb_ary_product(int argc, VALUE *argv, VALUE ary) return result; } +/* + * call-seq: + * ary.take(n) => array + * + * Returns first n elements from <i>ary</i>. + * + * a = [1, 2, 3, 4, 5, 0] + * a.take(3) # => [1, 2, 3] + * + */ + +static VALUE +rb_ary_take(VALUE obj, VALUE n) +{ + return rb_ary_subseq(obj, 0, FIX2LONG(n)); +} + +/* + * call-seq: + * ary.take_while {|arr| block } => array + * + * Passes elements to the block until the block returns nil or false, + * then stops iterating and returns an array of all prior elements. + * + * a = [1, 2, 3, 4, 5, 0] + * a.take_while {|i| i < 3 } # => [1, 2] + * + */ + +static VALUE +rb_ary_take_while(VALUE ary) +{ + VALUE result; + long i; + + RETURN_ENUMERATOR(ary, 0, 0); + for (i = 0; i < RARRAY_LEN(ary); i++) { + if (!RTEST(rb_yield(RARRAY_PTR(ary)[i]))) break; + } + return rb_ary_take(ary, LONG2FIX(i)); +} + +/* + * call-seq: + * ary.drop(n) => array + * + * Drops first n elements from <i>ary</i>, and returns rest elements + * in an array. + * + * a = [1, 2, 3, 4, 5, 0] + * a.drop(3) # => [4, 5, 0] + * + */ + +static VALUE +rb_ary_drop(VALUE ary, VALUE n) +{ + VALUE result; + + result = rb_ary_subseq(ary, FIX2LONG(n), RARRAY_LEN(ary)); + if (result == Qnil) result = rb_ary_new(); + return result; +} + +/* + * call-seq: + * ary.drop_while {|arr| block } => array + * + * Drops elements up to, but not including, the first element for + * which the block returns nil or false and returns an array + * containing the remaining elements. + * + * a = [1, 2, 3, 4, 5, 0] + * a.drop_while {|i| i < 3 } # => [3, 4, 5, 0] + * + */ + +static VALUE +rb_ary_drop_while(VALUE ary) +{ + VALUE result; + long i; + + RETURN_ENUMERATOR(ary, 0, 0); + for (i = 0; i < RARRAY_LEN(ary); i++) { + if (!RTEST(rb_yield(RARRAY_PTR(ary)[i]))) break; + } + return rb_ary_drop(ary, LONG2FIX(i)); +} + /* Arrays are ordered, integer-indexed collections of any object. @@ -3332,5 +3422,10 @@ Init_Array(void) rb_define_method(rb_cArray, "combination", rb_ary_combination, 1); rb_define_method(rb_cArray, "product", rb_ary_product, -1); + rb_define_method(rb_cArray, "take", rb_ary_take, 1); + rb_define_method(rb_cArray, "take_while", rb_ary_take_while, 0); + rb_define_method(rb_cArray, "drop", rb_ary_drop, 1); + rb_define_method(rb_cArray, "drop_while", rb_ary_drop_while, 0); + id_cmp = rb_intern("<=>"); } |