go 比较两个字符串的版本号大小

1package main
2
3import "fmt"
4
5func VersionOrdinal(version string) string {
6	// ISO/IEC 14651:2011
7	const maxByte = 1<<8 - 1
8	vo := make([]byte, 0, len(version)+8)
9	j := -1
10	for i := 0; i < len(version); i++ {
11		b := version[i]
12		if '0' > b || b > '9' {
13			vo = append(vo, b)
14			j = -1
15			continue
16		}
17		if j == -1 {
18			vo = append(vo, 0x00)
19			j = len(vo) - 1
20		}
21		if vo[j] == 1 && vo[j+1] == '0' {
22			vo[j+1] = b
23			continue
24		}
25		if vo[j]+1 > maxByte {
26			panic("VersionOrdinal: invalid version")
27		}
28		vo = append(vo, b)
29		vo[j]++
30	}
31	return string(vo)
32}
33
34func main() {
35	versions := []struct{ a, b string }{
36		{"1.05.00.0156", "1.0.221.9289"},
37		// Go versions
38		{"1", "1.0.1"},
39		{"1.0.1", "1.0.2"},
40		{"1.0.2", "1.0.3"},
41		{"1.0.3", "1.1"},
42		{"1.1", "1.1.1"},
43		{"1.1.1", "1.1.2"},
44		{"1.1.2", "1.2"},
45	}
46	for _, version := range versions {
47		a, b := VersionOrdinal(version.a), VersionOrdinal(version.b)
48		switch {
49		case a > b:
50			fmt.Println(version.a, ">", version.b)
51		case a < b:
52			fmt.Println(version.a, "<", version.b)
53		case a == b:
54			fmt.Println(version.a, "=", version.b)
55		}
56	}
57}