1 // Copyright 2023 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Package gover implements support for Go toolchain versions like 1.21.0 and 1.21rc1. 6 // (For historical reasons, Go does not use semver for its toolchains.) 7 // This package provides the same basic analysis that golang.org/x/mod/semver does for semver. 8 // It also provides some helpers for extracting versions from go.mod files 9 // and for dealing with module.Versions that may use Go versions or semver 10 // depending on the module path. 11 package gover 12 13 import ( 14 "internal/gover" 15 ) 16 17 // Compare returns -1, 0, or +1 depending on whether 18 // x < y, x == y, or x > y, interpreted as toolchain versions. 19 // The versions x and y must not begin with a "go" prefix: just "1.21" not "go1.21". 20 // Malformed versions compare less than well-formed versions and equal to each other. 21 // The language version "1.21" compares less than the release candidate and eventual releases "1.21rc1" and "1.21.0". 22 func Compare(x, y string) int { 23 return gover.Compare(x, y) 24 } 25 26 // Max returns the maximum of x and y interpreted as toolchain versions, 27 // compared using Compare. 28 // If x and y compare equal, Max returns x. 29 func Max(x, y string) string { 30 return gover.Max(x, y) 31 } 32 33 // IsLang reports whether v denotes the overall Go language version 34 // and not a specific release. Starting with the Go 1.21 release, "1.x" denotes 35 // the overall language version; the first release is "1.x.0". 36 // The distinction is important because the relative ordering is 37 // 38 // 1.21 < 1.21rc1 < 1.21.0 39 // 40 // meaning that Go 1.21rc1 and Go 1.21.0 will both handle go.mod files that 41 // say "go 1.21", but Go 1.21rc1 will not handle files that say "go 1.21.0". 42 func IsLang(x string) bool { 43 return gover.IsLang(x) 44 } 45 46 // Lang returns the Go language version. For example, Lang("1.2.3") == "1.2". 47 func Lang(x string) string { 48 return gover.Lang(x) 49 } 50 51 // IsPrerelease reports whether v denotes a Go prerelease version. 52 func IsPrerelease(x string) bool { 53 return gover.Parse(x).Kind != "" 54 } 55 56 // Prev returns the Go major release immediately preceding v, 57 // or v itself if v is the first Go major release (1.0) or not a supported 58 // Go version. 59 // 60 // Examples: 61 // 62 // Prev("1.2") = "1.1" 63 // Prev("1.3rc4") = "1.2" 64 func Prev(x string) string { 65 v := gover.Parse(x) 66 if gover.CmpInt(v.Minor, "1") <= 0 { 67 return v.Major 68 } 69 return v.Major + "." + gover.DecInt(v.Minor) 70 } 71 72 // IsValid reports whether the version x is valid. 73 func IsValid(x string) bool { 74 return gover.IsValid(x) 75 } 76