Add an Iterable package with handy functions like All, Any and Map.

Add a Data method to vector.Vector.

R=r,rsc
APPROVED=rsc
DELTA=173  (170 added, 0 deleted, 3 changed)
OCL=26980
CL=27098

1 files changed, 78 insertions, 0 deletions

diff --git a/src/lib/container/iterable_test.go b/src/lib/container/iterable_test.go
new file mode 100644
index 000000000..9c7d29110
--- /dev/null
+++ b/src/lib/container/iterable_test.go
@@ -0,0 +1,78 @@
+// 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.
+
+package iterable
+
+import (
+	"iterable";
+	"testing";
+)
+
+type IntArray []int;
+
+func (arr IntArray) Iter() <-chan interface {} {
+	ch := make(chan interface {});
+	go func() {
+		for i, x := range arr {
+			ch <- x
+		}
+		close(ch)
+	}();
+	return ch
+}
+
+var oneToFive IntArray = []int{ 1, 2, 3, 4, 5 };
+
+func isNegative(n interface {}) bool {
+	return n.(int) < 0
+}
+func isPositive(n interface {}) bool {
+	return n.(int) > 0
+}
+func isAbove3(n interface {}) bool {
+	return n.(int) > 3
+}
+func isEven(n interface {}) bool {
+	return n.(int) % 2 == 0
+}
+func doubler(n interface {}) interface {} {
+	return n.(int) * 2
+}
+func addOne(n interface {}) interface {} {
+	return n.(int) + 1
+}
+
+
+func TestAll(t *testing.T) {
+	if !All(oneToFive, isPositive) {
+		t.Error("All(oneToFive, isPositive) == false")
+	}
+	if All(oneToFive, isAbove3) {
+		t.Error("All(oneToFive, isAbove3) == true")
+	}
+}
+
+
+func TestAny(t *testing.T) {
+	if Any(oneToFive, isNegative) {
+		t.Error("Any(oneToFive, isNegative) == true")
+	}
+	if !Any(oneToFive, isEven) {
+		t.Error("Any(oneToFive, isEven) == false")
+	}
+}
+
+
+func TestMap(t *testing.T) {
+	res := Data(Map(Map(oneToFive, doubler), addOne));
+	if len(res) != len(oneToFive) {
+		t.Fatal("len(res) = %v, want %v", len(res), len(oneToFive))
+	}
+	expected := []int{ 3, 5, 7, 9, 11 };
+	for i := range res {
+		if res[i].(int) != expected[i] {
+			t.Errorf("res[%v] = %v, want %v", i, res[i], expected[i])
+		}
+	}
+}