{"go1.6", "go1.6.1", -1},
	{"go1.19", "go1.19.0", 0},
	{"go1.19rc1", "go1.19", -1},
	{"go1.20", "go1.20.0", 0},
	{"go1.20", "go1.20.0-bigcorp", 0},
	{"go1.20rc1", "go1.20", -1},
	{"go1.21", "go1.21.0", -1},
	{"go1.21", "go1.21.0-bigcorp", -1},
	{"go1.21", "go1.21rc1", -1},
	{"go1.21rc1", "go1.21.0", -1},
	{"go1.6", "go1.19", -1},
	{"go1.19", "go1.19.1", -1},
	{"go1.19rc1", "go1.19", -1},
	{"go1.19rc1", "go1.19", -1},

// 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".
func Compare(x, y string) int {
	return gover.Compare(stripGo(x), stripGo(y))
}

// IsValid reports whether the version x is valid.
func IsValid(x string) bool {
	return gover.IsValid(stripGo(x))

// 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 { return compare(stripGo(x), stripGo(y)) }

	// so if the latest release is 1.40.1 we'll take the latest 1.39.X.
	// Failing that, we prefer the latest patch release before the most recent
	// prerelease family, so if the latest release is 1.40rc1 is out but 1.39 is okay,
	// we'll still take 1.39.X.
	// Failing that we'll take the latest release.
	latest := ""
	for i := len(list) - 1; i >= 0; i-- {
		v := list[i]
		if gover.Compare(v, need) < 0 {

	Context *Context

	// GoVersion describes the accepted Go language version. The string must
	// start with a prefix of the form "go%d.%d" (e.g. "go1.20", "go1.21rc1", or
	// "go1.21.0") or it must be empty; an empty string disables Go language
	// version checks. If the format is invalid, invoking the type checker will
	// result in an error.
	GoVersion string

	Context *Context

	// GoVersion describes the accepted Go language version. The string must
	// start with a prefix of the form "go%d.%d" (e.g. "go1.20", "go1.21rc1", or
	// "go1.21.0") or it must be empty; an empty string disables Go language
	// version checks. If the format is invalid, invoking the type checker will
	// result in an error.
	GoVersion string

	Syntax     *Line
}

// A Go is the go statement.
type Go struct {
	Version string // "1.23"
	Syntax  *Line
}

// A Toolchain is the toolchain statement.
type Toolchain struct {
	Name   string // "go1.21rc1"
	Syntax *Line
}

// A Godebug is a single godebug key=value statement.
type Godebug struct {
	Key    string
	Value  string
	Syntax *Line
}

// An Exclude is a single exclude statement.

20BF          ; valid                  ;      ; NV8    # 10.0 BITCOIN SIGN
20C0          ; valid                  ;      ; NV8    # 14.0 SOM SIGN
20C1..20CF    ; disallowed                             # NA   <reserved-20C1>..<reserved-20CF>
20D0..20E1    ; valid                  ;      ; NV8    # 1.1  COMBINING LEFT HARPOON ABOVE..COMBINING LEFT RIGHT ARROW ABOVE