diff options
author | knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2008-04-13 14:59:55 +0000 |
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committer | knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2008-04-13 14:59:55 +0000 |
commit | 181f815591030e9659643f8d6802eb5397ddac86 (patch) | |
tree | 966fc49fec416dad167b1fa3c8bba5e4218af355 /enum.c | |
parent | 31a060f7bd55a845824883b87700ca5bb39f7ab0 (diff) | |
download | ruby-181f815591030e9659643f8d6802eb5397ddac86.tar.gz |
* enum.c (enum_cycle): Make Enumerable#cycle do a finite loop when
the number of cycles is specified.
* array.c (rb_ary_cycle): Ditto for Array#cycle.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@15991 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'enum.c')
-rw-r--r-- | enum.c | 35 |
1 files changed, 25 insertions, 10 deletions
@@ -1656,33 +1656,48 @@ cycle_i(VALUE i, VALUE ary, int argc, VALUE *argv) /* * call-seq: * enum.cycle {|obj| block } + * enum.cycle(n) {|obj| block } * - * Calls <i>block</i> for each element of <i>enum</i> repeatedly - * forever. Returns nil if and only if the collection is empty. + * Calls <i>block</i> for each element of <i>enum</i> repeatedly _n_ + * times or forever if none or nil is given. If a non-positive + * number is given or the collection is empty, does nothing. Returns + * nil if the loop has finished without getting interrupted. + * * Enumerable#cycle saves elements in an internal array so changes * to <i>enum</i> after the first pass have no effect. * * a = ["a", "b", "c"] * a.cycle {|x| puts x } # print, a, b, c, a, b, c,.. forever. + * a.cycle(2) {|x| puts x } # print, a, b, c, a, b, c. * */ static VALUE -enum_cycle(VALUE obj) +enum_cycle(int argc, VALUE *argv, VALUE obj) { VALUE ary; - long i, len; + VALUE nv = Qnil; + long n, i, len; - RETURN_ENUMERATOR(obj, 0, 0); + rb_scan_args(argc, argv, "01", &nv); + + RETURN_ENUMERATOR(obj, argc, argv); + if (NIL_P(nv)) { + n = -1; + } + else { + n = NUM2LONG(nv); + if (n <= 0) return Qnil; + } ary = rb_ary_new(); RBASIC(ary)->klass = 0; rb_block_call(obj, id_each, 0, 0, cycle_i, ary); len = RARRAY_LEN(ary); if (len == 0) return Qnil; - for (;;) { - for (i=0; i<len; i++) { - rb_yield(RARRAY_PTR(ary)[i]); - } + while (n < 0 || 0 < --n) { + for (i=0; i<len; i++) { + rb_yield(RARRAY_PTR(ary)[i]); + } } return Qnil; /* not reached */ } @@ -1741,7 +1756,7 @@ Init_Enumerable(void) rb_define_method(rb_mEnumerable, "take_while", enum_take_while, 0); rb_define_method(rb_mEnumerable, "drop", enum_drop, 1); rb_define_method(rb_mEnumerable, "drop_while", enum_drop_while, 0); - rb_define_method(rb_mEnumerable, "cycle", enum_cycle, 0); + rb_define_method(rb_mEnumerable, "cycle", enum_cycle, -1); id_eqq = rb_intern("==="); id_each = rb_intern("each"); |