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author | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-08-06 16:26:17 +0000 |
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committer | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-08-06 16:26:17 +0000 |
commit | b3e977a4c03e435a9a6edd305b03a2769c31df96 (patch) | |
tree | 0fd33678b9b4bbb6c86d83f37378d534093433c7 /enum.c | |
parent | 5956c7ab3ec70bc798b6843e0fb17e22424d5083 (diff) | |
download | ruby-b3e977a4c03e435a9a6edd305b03a2769c31df96.tar.gz |
* enum.c (enum_cycle): new method to cycle enumerable forever.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@12890 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'enum.c')
-rw-r--r-- | enum.c | 39 |
1 files changed, 39 insertions, 0 deletions
@@ -1526,6 +1526,44 @@ enum_drop(int argc, VALUE *argv, VALUE obj) return args[0]; } + +static VALUE +cycle_i(VALUE i, VALUE ary) +{ + rb_ary_push(ary, i); + rb_yield(i); + return Qnil; +} + +/* + * call-seq: + * enum.cycle {|obj| block } + * + * Calls <i>block</i> for each element of enumerable repeatedly + * forever. Enumerable#cycle saves elements in an internal array. + * + * a = ["a", "b", "c"] + * a.each {|x| puts x } # print, a, b, c, a, b, c,.. forever. + * + */ + +static VALUE +enum_cycle(VALUE obj) +{ + VALUE ary; + long i; + + RETURN_ENUMERATOR(obj, 0, 0); + ary = rb_ary_new(); + rb_block_call(obj, id_each, 0, 0, cycle_i, ary); + for (;;) { + for (i=0; i<RARRAY_LEN(ary); i++) { + rb_yield(RARRAY_PTR(ary)[i]); + } + } + return Qnil; +} + /* * The <code>Enumerable</code> mixin provides collection classes with * several traversal and searching methods, and with the ability to @@ -1578,6 +1616,7 @@ Init_Enumerable(void) rb_define_method(rb_mEnumerable, "zip", enum_zip, -1); rb_define_method(rb_mEnumerable, "take", enum_take, -1); rb_define_method(rb_mEnumerable, "drop", enum_drop, -1); + rb_define_method(rb_mEnumerable, "cycle", enum_cycle, 0); id_eqq = rb_intern("==="); id_each = rb_intern("each"); |