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11 package main
12
13 import (
14 "bytes"
15 "log"
16 "os"
17 "strings"
18 )
19
20 func main() {
21 log.SetPrefix("gen: ")
22 log.SetFlags(0)
23
24 data, err := os.ReadFile("sais.go")
25 if err != nil {
26 log.Fatal(err)
27 }
28
29 x := bytes.Index(data, []byte("\n\n"))
30 if x < 0 {
31 log.Fatal("cannot find blank line after copyright comment")
32 }
33
34 var buf bytes.Buffer
35 buf.Write(data[:x])
36 buf.WriteString("\n\n// Code generated by go generate; DO NOT EDIT.\n\npackage suffixarray\n")
37
38 for {
39 x := bytes.Index(data, []byte("\nfunc "))
40 if x < 0 {
41 break
42 }
43 data = data[x:]
44 p := bytes.IndexByte(data, '(')
45 if p < 0 {
46 p = len(data)
47 }
48 name := string(data[len("\nfunc "):p])
49
50 x = bytes.Index(data, []byte("\n}\n"))
51 if x < 0 {
52 log.Fatalf("cannot find end of func %s", name)
53 }
54 fn := string(data[:x+len("\n}\n")])
55 data = data[x+len("\n}"):]
56
57 if strings.HasSuffix(name, "_32") {
58 buf.WriteString(fix32.Replace(fn))
59 }
60 if strings.HasSuffix(name, "_8_32") {
61
62 fn = fix8_32.Replace(stripByteOnly(fn))
63 buf.WriteString(fn)
64 buf.WriteString(fix32.Replace(fn))
65 }
66 }
67
68 if err := os.WriteFile("sais2.go", buf.Bytes(), 0666); err != nil {
69 log.Fatal(err)
70 }
71 }
72
73 var fix32 = strings.NewReplacer(
74 "32", "64",
75 "int32", "int64",
76 )
77
78 var fix8_32 = strings.NewReplacer(
79 "_8_32", "_32",
80 "byte", "int32",
81 )
82
83 func stripByteOnly(s string) string {
84 lines := strings.SplitAfter(s, "\n")
85 w := 0
86 for _, line := range lines {
87 if !strings.Contains(line, "256") && !strings.Contains(line, "byte-only") {
88 lines[w] = line
89 w++
90 }
91 }
92 return strings.Join(lines[:w], "")
93 }
94
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