added reduce method to Mojo::Collection

mojolicious · Aug 4, 2014 · 3c18fa3 · 3c18fa3
1 parent df23566
commit 3c18fa3
Show file tree

Hide file tree

Showing 3 changed files with 22 additions and 0 deletions.
diff --git a/Changes b/Changes
@@ -1,5 +1,6 @@
 
 5.25  2014-08-04
+  - Added reduce method to Mojo::Collection.
   - Fixed escaping bugs in Mojo::DOM::CSS.
 
 5.24  2014-08-02

diff --git a/lib/Mojo/Collection.pm b/lib/Mojo/Collection.pm
@@ -73,6 +73,11 @@ sub pluck {
   return $self->new(map { $_->$method(@args) } @$self);
 }
 
+sub reduce {
+  my ($self, $cb) = (shift, shift);
+  return List::Util::reduce(sub { $a->$cb($b) }, @_, @$self);
+}
+
 sub reverse { $_[0]->new(reverse @{$_[0]}) }
 
 sub shuffle { $_[0]->new(List::Util::shuffle @{$_[0]}) }
@@ -251,6 +256,16 @@ results.
   # Equal to but more convenient than
   my $new = $collection->map(sub { $_->$method(@args) });
 
+=head2 reduce
+
+  my $result = $collection->reduce(sub {...});
+  my $result = $collection->reduce(sub {...}, $initial);
+
+Reduce elements in collection with callback, the first element will be used as
+initial value if none has been provided.
+
+  my $sum = $collection->reduce(sub { shift() + shift() });
+
 =head2 reverse
 
   my $new = $collection->reverse;

diff --git a/t/mojo/collection.t b/t/mojo/collection.t
@@ -112,6 +112,12 @@ is $collection->size, 1, 'right size';
 $collection = c(5, 4, 3, 2, 1);
 is $collection->size, 5, 'right size';
 
+# reduce
+$collection = c(2, 5, 4, 1);
+is $collection->reduce(sub { shift() + shift() }), 12, 'right result';
+is $collection->reduce(sub { shift() + shift() }, 5), 17, 'right result';
+is c()->reduce(sub { shift() + shift() }), undef, 'no result';
+
 # sort
 $collection = c(2, 5, 4, 1);
 is_deeply [$collection->sort->each], [1, 2, 4, 5], 'right order';