1 files changed, 80 insertions, 0 deletions
diff --git a/src/lib/container/iterable.go b/src/lib/container/iterable.go
new file mode 100644
index 000000000..7963d14b5
--- /dev/null
+++ b/src/lib/container/iterable.go
@@ -0,0 +1,80 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The iterable package provides several traversal and searching methods.
+// It can be used on anything that satisfies the Iterable interface,
+// including vector, though certain functions, such as Map, can also be used on
+// something that would produce an infinite amount of data.
+package iterable
+
+import "vector"
+
+
+type Iterable interface {
+	// Iter should return a fresh channel each time it is called.
+	Iter() <-chan interface {}
+}
+
+
+// All tests whether f is true for every element of iter.
+func All(iter Iterable, f func(e interface {}) bool) bool {
+	for e := range iter.Iter() {
+		if !f(e) {
+			return false
+		}
+	}
+	return true
+}
+
+
+// Any tests whether f is true for at least one element of iter.
+func Any(iter Iterable, f func(e interface {}) bool) bool {
+	return !All(iter, func(e interface {}) bool { return !f(e) });
+}
+
+
+// Data returns a slice containing the elements of iter.
+func Data(iter Iterable) []interface {} {
+	vec := vector.New(0);
+	for e := range iter.Iter() {
+		vec.Push(e)
+	}
+	return vec.Data()
+}
+
+
+// mappedIterable is a helper struct that implements Iterable, returned by Map.
+type mappedIterable struct {
+	it Iterable;
+	f func(interface {}) interface {};
+}
+
+
+func (m mappedIterable) iterate(out chan<- interface {}) {
+	for e := range m.it.Iter() {
+		out <- m.f(e)
+	}
+	close(out)
+}
+
+
+func (m mappedIterable) Iter() <-chan interface {} {
+	ch := make(chan interface {});
+	go m.iterate(ch);
+	return ch;
+}
+
+
+// Map returns an Iterable that returns the result of applying f to each
+// element of iter.
+func Map(iter Iterable, f func(e interface {}) interface {}) Iterable {
+	return mappedIterable{ iter, f }
+}
+
+
+// TODO:
+// - Find, Filter
+// - Inject
+// - Partition
+// - Zip