go/src/cmd/go/internal/gover/toolchain.go

// FromToolchain returns the Go version for the named toolchain,
// derived from the name itself (not by running the toolchain).
// A toolchain is named "goVERSION".
// A suffix after the VERSION introduced by a -, space, or tab is removed.
// Examples:
//
//	FromToolchain("go1.2.3") == "1.2.3"
//	FromToolchain("go1.2.3-bigcorp") == "1.2.3"
//	FromToolchain("invalid") == ""
func FromToolchain(name string) string { … }

func maybeToolchainVersion(name string) string { … }

// ToolchainMax returns the maximum of x and y interpreted as toolchain names,
// compared using Compare(FromToolchain(x), FromToolchain(y)).
// If x and y compare equal, Max returns x.
func ToolchainMax(x, y string) string { … }

var Startup …

type TooNewError …

func (e *TooNewError) Error() string { … }

var ErrTooNew …

func (e *TooNewError) Is(err error) bool { … }

type Switcher …