sort: binary search for sorted slices
R=r, r2
CC=golang-dev
https://golang.org/cl/2997041
diff --git a/src/pkg/sort/search_test.go b/src/pkg/sort/search_test.go
new file mode 100644
index 0000000..ecd363e
--- /dev/null
+++ b/src/pkg/sort/search_test.go
@@ -0,0 +1,83 @@
+// Copyright 2010 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 sort
+
+import "testing"
+
+
+func f(a []int, x int) func(int) bool {
+ return func(i int) bool {
+ return a[i] <= x
+ }
+}
+
+
+var data = []int{0: -10, 1: -5, 2: 0, 3: 1, 4: 2, 5: 3, 6: 5, 7: 7, 8: 11, 9: 100, 10: 100, 11: 100, 12: 1000, 13: 10000}
+
+var tests = []struct {
+ name string
+ n int
+ f func(int) bool
+ i int
+}{
+ {"empty", 0, nil, 0},
+ {"1 1", 1, func(i int) bool { return i <= 1 }, 0},
+ {"1 true", 1, func(i int) bool { return false }, 0},
+ {"1 false", 1, func(i int) bool { return true }, 0},
+ {"1e9 991", 1e9, func(i int) bool { return i <= 991 }, 991},
+ {"1e9 true", 1e9, func(i int) bool { return false }, 0},
+ {"1e9 false", 1e9, func(i int) bool { return true }, 1e9 - 1},
+ {"data -20", len(data), f(data, -20), 0},
+ {"data -10", len(data), f(data, -10), 0},
+ {"data -9", len(data), f(data, -9), 0},
+ {"data -6", len(data), f(data, -6), 0},
+ {"data -5", len(data), f(data, -5), 1},
+ {"data 3", len(data), f(data, 3), 5},
+ {"data 99", len(data), f(data, 99), 8},
+ {"data 100", len(data), f(data, 100), 11},
+ {"data 101", len(data), f(data, 101), 11},
+ {"data 10000", len(data), f(data, 10000), 13},
+ {"data 10001", len(data), f(data, 10001), 13},
+ {"descending a", 7, func(i int) bool { return []int{99, 99, 59, 42, 7, 0, -1, -1}[i] >= 7 }, 4},
+ {"descending 7", 1e9, func(i int) bool { return 1e9-i >= 7 }, 1e9 - 7},
+}
+
+
+func TestSearch(t *testing.T) {
+ for _, e := range tests {
+ i := Search(e.n, e.f)
+ if i != e.i {
+ t.Errorf("%s: expected index %d; got %d", e.name, e.i, i)
+ }
+ }
+}
+
+
+// Smoke tests for convenience wrappers - not comprehensive.
+
+var fdata = []float{0: -3.14, 1: 0, 2: 1, 3: 2, 4: 1000.7}
+var sdata = []string{0: "f", 1: "foo", 2: "foobar", 3: "x"}
+
+var wrappertests = []struct {
+ name string
+ result int
+ i int
+}{
+ {"SearchInts", SearchInts(data, 11), 8},
+ {"SearchFloats", SearchFloats(fdata, 2.1), 3},
+ {"SearchStrings", SearchStrings(sdata, ""), 0},
+ {"IntArray.Search", IntArray(data).Search(0), 2},
+ {"FloatArray.Search", FloatArray(fdata).Search(2.0), 3},
+ {"StringArray.Search", StringArray(sdata).Search("x"), 3},
+}
+
+
+func TestSearchWrappers(t *testing.T) {
+ for _, e := range wrappertests {
+ if e.result != e.i {
+ t.Errorf("%s: expected index %d; got %d", e.name, e.i, e.result)
+ }
+ }
+}
