Source file src/pkg/math/bits/make_examples.go
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8
9 package main
10
11 import (
12 "bytes"
13 "fmt"
14 "io/ioutil"
15 "log"
16 "math/bits"
17 )
18
19 const header = `// Copyright 2017 The Go Authors. All rights reserved.
20 // Use of this source code is governed by a BSD-style
21 // license that can be found in the LICENSE file.
22
23 // Code generated by go run make_examples.go. DO NOT EDIT.
24
25 package bits_test
26
27 import (
28 "fmt"
29 "math/bits"
30 )
31 `
32
33 func main() {
34 w := bytes.NewBuffer([]byte(header))
35
36 for _, e := range []struct {
37 name string
38 in int
39 out [4]interface{}
40 out2 [4]interface{}
41 }{
42 {
43 name: "LeadingZeros",
44 in: 1,
45 out: [4]interface{}{bits.LeadingZeros8(1), bits.LeadingZeros16(1), bits.LeadingZeros32(1), bits.LeadingZeros64(1)},
46 },
47 {
48 name: "TrailingZeros",
49 in: 14,
50 out: [4]interface{}{bits.TrailingZeros8(14), bits.TrailingZeros16(14), bits.TrailingZeros32(14), bits.TrailingZeros64(14)},
51 },
52 {
53 name: "OnesCount",
54 in: 14,
55 out: [4]interface{}{bits.OnesCount8(14), bits.OnesCount16(14), bits.OnesCount32(14), bits.OnesCount64(14)},
56 },
57 {
58 name: "RotateLeft",
59 in: 15,
60 out: [4]interface{}{bits.RotateLeft8(15, 2), bits.RotateLeft16(15, 2), bits.RotateLeft32(15, 2), bits.RotateLeft64(15, 2)},
61 out2: [4]interface{}{bits.RotateLeft8(15, -2), bits.RotateLeft16(15, -2), bits.RotateLeft32(15, -2), bits.RotateLeft64(15, -2)},
62 },
63 {
64 name: "Reverse",
65 in: 19,
66 out: [4]interface{}{bits.Reverse8(19), bits.Reverse16(19), bits.Reverse32(19), bits.Reverse64(19)},
67 },
68 {
69 name: "ReverseBytes",
70 in: 15,
71 out: [4]interface{}{nil, bits.ReverseBytes16(15), bits.ReverseBytes32(15), bits.ReverseBytes64(15)},
72 },
73 {
74 name: "Len",
75 in: 8,
76 out: [4]interface{}{bits.Len8(8), bits.Len16(8), bits.Len32(8), bits.Len64(8)},
77 },
78 } {
79 for i, size := range []int{8, 16, 32, 64} {
80 if e.out[i] == nil {
81 continue
82 }
83 f := fmt.Sprintf("%s%d", e.name, size)
84 fmt.Fprintf(w, "\nfunc Example%s() {\n", f)
85 switch e.name {
86 case "RotateLeft", "Reverse", "ReverseBytes":
87 fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", %d)\n", size, e.in)
88 if e.name == "RotateLeft" {
89 fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d, 2))\n", size, f, e.in)
90 fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d, -2))\n", size, f, e.in)
91 } else {
92 fmt.Fprintf(w, "\tfmt.Printf(\"%%0%db\\n\", bits.%s(%d))\n", size, f, e.in)
93 }
94 fmt.Fprintf(w, "\t// Output:\n")
95 fmt.Fprintf(w, "\t// %0*b\n", size, e.in)
96 fmt.Fprintf(w, "\t// %0*b\n", size, e.out[i])
97 if e.name == "RotateLeft" && e.out2[i] != nil {
98 fmt.Fprintf(w, "\t// %0*b\n", size, e.out2[i])
99 }
100 default:
101 fmt.Fprintf(w, "\tfmt.Printf(\"%s(%%0%db) = %%d\\n\", %d, bits.%s(%d))\n", f, size, e.in, f, e.in)
102 fmt.Fprintf(w, "\t// Output:\n")
103 fmt.Fprintf(w, "\t// %s(%0*b) = %d\n", f, size, e.in, e.out[i])
104 }
105 fmt.Fprintf(w, "}\n")
106 }
107 }
108
109 if err := ioutil.WriteFile("example_test.go", w.Bytes(), 0666); err != nil {
110 log.Fatal(err)
111 }
112 }
113
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