diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | array.c | 95 | ||||
| -rw-r--r-- | test/ruby/test_array.rb | 16 |
3 files changed, 118 insertions, 0 deletions
@@ -1,3 +1,10 @@ +Mon Mar 17 22:23:54 2008 Yusuke Endoh <mame@tsg.ne.jp> + + * array.c (rb_ary_take, rb_ary_take_while, rb_ary_drop, + rb_ary_drop_while): new methods. [ruby-dev:34067] + + * test/ruby/test_array.rb: add tests for above. + Mon Mar 17 17:11:13 2008 Nobuyoshi Nakada <nobu@ruby-lang.org> * misc/ruby-mode.el (ruby-mode): should use `run-mode-hooks' instead @@ -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("<=>"); } diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb index c0206baed5..ea2cef85cd 100644 --- a/test/ruby/test_array.rb +++ b/test/ruby/test_array.rb @@ -1229,4 +1229,20 @@ class TestArray < Test::Unit::TestCase assert_equal(@cls[].permutation(0).to_a, @cls[[]]) end + + def test_take + assert_equal([1,2,3], [1,2,3,4,5,0].take(3)) + end + + def test_take_while + assert_equal([1,2], [1,2,3,4,5,0].take_while {|i| i < 3 }) + end + + def test_drop + assert_equal([4,5,0], [1,2,3,4,5,0].drop(3)) + end + + def test_drop_while + assert_equal([3,4,5,0], [1,2,3,4,5,0].drop_while {|i| i < 3 }) + end end |