return IsValid(FromToolchain(vers))
		}
		return IsValid(vers)
	}
	return semver.IsValid(vers)
}

// ModIsPrefix reports whether v is a valid version syntax prefix for the module with the given path.
// The caller is assumed to have checked that ModIsValid(path, vers) is true.
func ModIsPrefix(path, vers string) bool {
	if IsToolchain(path) {
		if path == "toolchain" {
			return IsLang(FromToolchain(vers))
		}

	if vers == "latest" ||
		vers == "upgrade" ||
		vers == "patch" ||
		strings.HasPrefix(vers, "<") ||
		strings.HasPrefix(vers, ">") ||
		(gover.ModIsValid(path, vers) && gover.ModIsPrefix(path, vers)) {
		return false
	}
	return true
}

type queryMatcher struct {
	path               string
	prefix             string
	filter             func(version string) bool