gotools/internal/versions/versions.go

// Lang returns the Go language version for version x.
// If x is not a valid version, Lang returns the empty string.
// For example:
//
//	Lang("go1.21rc2") = "go1.21"
//	Lang("go1.21.2") = "go1.21"
//	Lang("go1.21") = "go1.21"
//	Lang("go1") = "go1"
//	Lang("bad") = ""
//	Lang("1.21") = ""
func Lang(x string) string { … }

// Compare returns -1, 0, or +1 depending on whether
// x < y, x == y, or x > y, interpreted as Go versions.
// The versions x and y must begin with a "go" prefix: "go1.21" not "1.21".
// Invalid versions, including the empty string, compare less than
// valid versions and equal to each other.
// The language version "go1.21" compares less than the
// release candidate and eventual releases "go1.21rc1" and "go1.21.0".
// Custom toolchain suffixes are ignored during comparison:
// "go1.21.0" and "go1.21.0-bigcorp" are equal.
func Compare(x, y string) int { … }

// IsValid reports whether the version x is valid.
func IsValid(x string) bool { … }

// stripGo converts from a "go1.21" version to a "1.21" version.
// If v does not start with "go", stripGo returns the empty string (a known invalid version).
func stripGo(v string) string { … }