diff options
author | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-06-23 15:05:05 +0000 |
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committer | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-06-23 15:05:05 +0000 |
commit | 3f2fe372005b0bd1f6535ffaaf23ff8ea4f8271f (patch) | |
tree | 4dcdc823721cd5e9f6090e1f2f0c42c217813077 /enum.c | |
parent | fe377d3b8e554856b27e00b4c4e1ccce0cb1ee5e (diff) |
* enum.c (enum_minmax): new method to get the minimum and maximum
values from the enumerable at once.
* enum.c (enum_minmax_by): ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@12590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'enum.c')
-rw-r--r-- | enum.c | 141 |
1 files changed, 139 insertions, 2 deletions
@@ -1048,6 +1048,90 @@ enum_max(VALUE obj) } static VALUE +minmax_i(VALUE i, VALUE *memo) +{ + int n; + + if (memo[0] == Qundef) { + memo[0] = i; + memo[1] = i; + } + else { + n = rb_cmpint(rb_funcall(i, id_cmp, 1, memo[0]), i, memo[0]); + if (n < 0) { + memo[0] = i; + } + n = rb_cmpint(rb_funcall(i, id_cmp, 1, memo[1]), i, memo[1]); + if (n > 0) { + memo[1] = i; + } + } + return Qnil; +} + +static VALUE +minmax_ii(VALUE i, VALUE *memo) +{ + int n; + + if (memo[0] == Qundef) { + memo[0] = i; + memo[1] = i; + } + else { + VALUE ary = memo[2]; + + RARRAY_PTR(ary)[0] = i; + RARRAY_PTR(ary)[1] = memo[0]; + n = rb_cmpint(rb_yield(ary), i, memo[0]); + if (n < 0) { + memo[0] = i; + } + RARRAY_PTR(ary)[0] = i; + RARRAY_PTR(ary)[1] = memo[1]; + n = rb_cmpint(rb_yield(ary), i, memo[1]); + if (n > 0) { + memo[1] = i; + } + } + return Qnil; +} + +/* + * call-seq: + * enum.minmax => [min,max] + * enum.minmax {|a,b| block } => [min,max] + * + * Returns two elements array which contains the mininum and the + * maxinum value in the enumerable. The first form assumes all + * objects implement <code>Comparable</code>; the second uses the + * block to return <em>a <=> b</em>. + * + * a = %w(albatross dog horse) + * a.minmax #=> ["albatross", "horse"] + * a.minmax {|a,b| a.length <=> b.length } #=> ["dog", "albatross"] + */ + +static VALUE +enum_minmax(VALUE obj) +{ + VALUE result[3]; + VALUE ary = rb_ary_new3(2, Qnil, Qnil); + + result[0] = Qundef; + if (rb_block_given_p()) { + result[2] = ary; + rb_block_call(obj, id_each, 0, 0, minmax_ii, (VALUE)result); + } + else { + rb_block_call(obj, id_each, 0, 0, minmax_i, (VALUE)result); + } + RARRAY_PTR(ary)[0] = result[0]; + RARRAY_PTR(ary)[1] = result[1]; + return ary; +} + +static VALUE min_by_i(VALUE i, VALUE *memo) { VALUE v; @@ -1130,6 +1214,58 @@ enum_max_by(VALUE obj) } static VALUE +minmax_by_i(VALUE i, VALUE *memo) +{ + VALUE v; + + v = rb_yield(i); + if (memo[0] == Qundef) { + memo[0] = v; + memo[1] = v; + memo[2] = i; + memo[3] = i; + } + else { + if (rb_cmpint(rb_funcall(v, id_cmp, 1, memo[0]), v, memo[0]) < 0) { + memo[0] = v; + memo[2] = i; + } + if (rb_cmpint(rb_funcall(v, id_cmp, 1, memo[1]), v, memo[1]) > 0) { + memo[1] = v; + memo[3] = i; + } + } + return Qnil; +} + +/* + * call-seq: + * enum.minmax_by {| obj| block } => [min, max] + * + * Returns two elements array array containing the objects in + * <i>enum</i> that gives the minmum and maximum values respectively + * from the given block. + * + * a = %w(albatross dog horse) + * a.minmax_by {|x| x.length } #=> ["dog", "albatross"] + */ + +static VALUE +enum_minmax_by(VALUE obj) +{ + VALUE memo[4]; + + RETURN_ENUMERATOR(obj, 0, 0); + + memo[0] = Qundef; + memo[1] = Qundef; + memo[2] = Qnil; + memo[3] = Qnil; + rb_block_call(obj, id_each, 0, 0, minmax_by_i, (VALUE)memo); + return rb_assoc_new(memo[2], memo[3]); +} + +static VALUE member_i(VALUE item, VALUE *memo) { if (rb_equal(item, memo[0])) { @@ -1425,8 +1561,9 @@ Init_Enumerable(void) rb_define_method(rb_mEnumerable,"none?", enum_none, 0); rb_define_method(rb_mEnumerable,"min", enum_min, 0); rb_define_method(rb_mEnumerable,"max", enum_max, 0); - rb_define_method(rb_mEnumerable,"min_by", enum_min_by, 0); - rb_define_method(rb_mEnumerable,"max_by", enum_max_by, 0); + rb_define_method(rb_mEnumerable,"minmax", enum_minmax, 0); + rb_define_method(rb_mEnumerable,"min_by", enum_min_by, 0); + rb_define_method(rb_mEnumerable,"minmax_by", enum_minmax_by, 0); rb_define_method(rb_mEnumerable,"member?", enum_member, 1); rb_define_method(rb_mEnumerable,"include?", enum_member, 1); rb_define_method(rb_mEnumerable,"each_with_index", enum_each_with_index, -1); |