if r < utf8.RuneSelf {
				const allowed = "!#$%&()+,-.=@^_{}~ "
				if '0' <= r && r <= '9' ||
					'a' <= r && r <= 'z' ||
					'A' <= r && r <= 'Z' {
					return r
				}
				if strings.ContainsRune(allowed, r) {
					return r
				}
			} else if unicode.IsLetter(r) || unicode.IsNumber(r) {
				return r
			}
			return -1
		}
		pattern := strings.Map(mapper, c.Name())

	// Should match Go spec, compilers, and ../../go/parser/parser.go:/isValidImport.
	const illegalChars = `!"#$%&'()*,:;<=>?[\]^{|}` + "`\uFFFD"
	if !unicode.IsGraphic(r) || unicode.IsSpace(r) || strings.ContainsRune(illegalChars, r) {
		return '_'
	}
	return r
}

// Mode flags for loadImport and download (in get.go).
const (
	// ResolveImport means that loadImport should do import path expansion.

		{"(*Reader).WriteTo", Method, 1},
		{"Buffer", Type, 0},
		{"Clone", Func, 20},
		{"Compare", Func, 0},
		{"Contains", Func, 0},
		{"ContainsAny", Func, 7},
		{"ContainsFunc", Func, 21},
		{"ContainsRune", Func, 7},
		{"Count", Func, 0},
		{"Cut", Func, 18},
		{"CutPrefix", Func, 20},
		{"CutSuffix", Func, 20},
		{"Equal", Func, 0},
		{"EqualFold", Func, 0},
		{"ErrTooLarge", Var, 0},

pkg strconv, var ErrRange error
pkg strconv, var ErrSyntax error
pkg strings, func Contains(string, string) bool
pkg strings, func ContainsAny(string, string) bool
pkg strings, func ContainsRune(string, int32) bool
pkg strings, func Count(string, string) int
pkg strings, func EqualFold(string, string) bool
pkg strings, func Fields(string) []string
pkg strings, func FieldsFunc(string, func(int32) bool) []string