Go 完整实现版本比较 VersionCompare 函数

【转】 http://www.syyong.com/Go/Go-implementation-version-comparison-VersionCompare-function.html

VersionCompare — 用于对比两个的版本数字字符串大小。

此函数首先在版本字符串里用一个点 . 替换 _、- 和 +，也会在任意非数字前后插入一个点 .，这样，类似 '4.3.2RC1' 将会变成 '4.3.2.RC.1'。 接下来它会分割结果，然后它会从左往右对比各个部分。如果某部分包含了特定的版本字符串，将会用以下顺序处理：列表中未找到的任意字符串 < dev < alpha = a < beta = b < RC = rc < # < pl = p。 这种方式不仅能够对比类似 '4.1' 和 '4.1.2' 那种不同的版本级别，同时也可以指定对比任何包含开发状态的版本。

VersionCompare

// version_compare()
// The possible operators are: <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne respectively.
// special version strings these are handled in the following order,
// (any string not found) < dev < alpha = a < beta = b < RC = rc < # < pl = p
// Usage:
// VersionCompare("1.2.3-alpha", "1.2.3RC7", '>=')
// VersionCompare("1.2.3-beta", "1.2.3pl", 'lt')
// VersionCompare("1.1_dev", "1.2any", 'eq')
func VersionCompare(version1, version2, operator string) bool {
    var vcompare func(string, string) int
    var canonicalize func(string) string
    var special func(string, string) int
 
    // version compare
    vcompare = func(origV1, origV2 string) int {
        if origV1 == "" || origV2 == "" {
            if origV1 == "" && origV2 == "" {
                return
            } else {
                if origV1 == "" {
                    return -
                } else {
                    return
                }
            }
        }
 
        ver1, ver2, compare := "", "",
        if origV1[] == '#' {
            ver1 = origV1
        } else {
            ver1 = canonicalize(origV1)
        }
        if origV2[] == '#' {
            ver2 = origV2
        } else {
            ver2 = canonicalize(origV2)
        }
        n1, n2 := ,
        for {
            p1, p2 := "", ""
            n1 = strings.IndexByte(ver1, '.')
            if n1 == - {
                p1, ver1 = ver1, ""
            } else {
                p1, ver1 = ver1[:n1], ver1[n1+:]
            }
            n2 = strings.IndexByte(ver2, '.')
            if n2 == - {
                p2, ver2 = ver2, ""
            } else {
                p2, ver2 = ver2[:n2], ver2[n2+:]
            }
            if (p1[] >= '' && p1[] <= '') && (p2[] >= '' && p2[] <= '') { // all isdigit
                l1, _ := strconv.Atoi(p1)
                l2, _ := strconv.Atoi(p2)
                if l1 > l2 {
                    compare =
                } else if l1 == l2 {
                    compare =
                } else {
                    compare = -
                }
            } else if !(p1[] >= '' && p1[] <= '') && !(p2[] >= '' && p2[] <= '') { // all isndigit
                compare = special(p1, p2)
            } else { // part isdigit
                if p1[] >= '' && p1[] <= '' { // isdigit
                    compare = special("#N#", p2)
                } else {
                    compare = special(p1, "#N#")
                }
            }
            if compare !=  || n1 == - || n2 == - {
                break
            }
        }
 
        if compare ==  {
            if ver1 != "" {
                if ver1[] >= '' && ver1[] <= '' {
                    compare =
                } else {
                    compare = vcompare(ver1, "#N#")
                }
            } else if ver2 != "" {
                if ver2[] >= '' && ver2[] <= '' {
                    compare = -
                } else {
                    compare = vcompare("#N#", ver2)
                }
            }
        }
 
        return compare
    }
 
    // canonicalize
    canonicalize = func(version string) string {
        ver := []byte(version)
        l := len(ver)
        if l ==  {
            return ""
        }
        var buf = make([]byte, l*)
        j :=
        for i, v := range ver {
            next := uint8()
            if i+ < l { // Have the next one
                next = ver[i+]
            }
            if v == '-' || v == '_' || v == '+' { // repalce "-","_","+" to "."
                if j >  && buf[j-] != '.' {
                    buf[j] = '.'
                    j++
                }
            } else if (next > ) &&
                (!(next >= '' && next <= '') && (v >= '' && v <= '')) ||
                (!(v >= '' && v <= '') && (next >= '' && next <= '')) { // Insert '.' before and after a non-digit
                buf[j] = v
                j++
                if v != '.' && next != '.' {
                    buf[j] = '.'
                    j++
                }
                continue
            } else if !((v >= '' && v <= '') ||
                (v >= 'a' && v <= 'z') || (v >= 'A' && v <= 'Z')) { // Non-letters and numbers
                if j >  && buf[j-] != '.' {
                    buf[j] = '.'
                    j++
                }
            } else {
                buf[j] = v
                j++
            }
        }
 
        return string(buf[:j])
    }
 
    //compare special version forms
    special = func(form1, form2 string) int {
        found1, found2, len1, len2 := -, -, len(form1), len(form2)
        // (Any string not found) < dev < alpha = a < beta = b < RC = rc < # < pl = p
        forms := map[string]int{
            "dev":   ,
            "alpha": ,
            "a":     ,
            "beta":  ,
            "b":     ,
            "RC":    ,
            "rc":    ,
            "#":     ,
            "pl":    ,
            "p":     ,
        }
 
        for name, order := range forms {
            if len1 < len(name) {
                continue
            }
            if strings.Compare(form1[:len(name)], name) ==  {
                found1 = order
                break
            }
        }
        for name, order := range forms {
            if len2 < len(name) {
                continue
            }
            if strings.Compare(form2[:len(name)], name) ==  {
                found2 = order
                break
            }
        }
 
        if found1 == found2 {
            return
        } else if found1 > found2 {
            return
        } else {
            return -
        }
    }
 
    compare := vcompare(version1, version2)
 
    switch operator {
    case "<", "lt":
        return compare == -
    case "<=", "le":
        return compare !=
    case ">", "gt":
        return compare ==
    case ">=", "ge":
        return compare != -
    case "==", "=", "eq":
        return compare ==
    case "!=", "<>", "ne":
        return compare !=
    default:
        panic("operator: invalid")
    }
}

Github地址

https://github.com/syyongx/php2go