}
        return result.toString();
    }

    private static boolean isCppIdentifierCharacterStart(char c) {
        return Character.isLetter(c) || c == '_';
    }

    private static boolean isCppIdentifierCharacterPart(char c) {
        return Character.isLetter(c) || Character.isDigit(c) || c == '_';
    }

func TestIsLetter(t *testing.T) {
	for _, r := range upperTest {
		if !IsLetter(r) {
			t.Errorf("IsLetter(U+%04X) = false, want true", r)
		}
	}
	for _, r := range letterTest {
		if !IsLetter(r) {
			t.Errorf("IsLetter(U+%04X) = false, want true", r)
		}
	}
	for _, r := range notletterTest {
		if IsLetter(r) {
			t.Errorf("IsLetter(U+%04X) = true, want false", r)
		}
	}
}

		return !unicode.IsLetter(r) && !unicode.IsNumber(r)
	}))
	// Output: Hello, Gophers
}

func ExampleTrimLeft() {
	fmt.Print(strings.TrimLeft("¡¡¡Hello, Gophers!!!", "!¡"))
	// Output: Hello, Gophers!!!
}

func ExampleTrimLeftFunc() {
	fmt.Print(strings.TrimLeftFunc("¡¡¡Hello, Gophers!!!", func(r rune) bool {
		return !unicode.IsLetter(r) && !unicode.IsNumber(r)
	}))

	fmt.Printf("%t\n", unicode.IsNumber('Ⅷ'))
	fmt.Printf("%t\n", unicode.IsNumber('A'))
	// Output:
	// true
	// false
}

func ExampleIsLetter() {
	fmt.Printf("%t\n", unicode.IsLetter('A'))
	fmt.Printf("%t\n", unicode.IsLetter('7'))
	// Output:
	// true
	// false
}

func ExampleIsLower() {
	fmt.Printf("%t\n", unicode.IsLower('a'))
	fmt.Printf("%t\n", unicode.IsLower('A'))
	// Output:
	// true

// isBreak returns whether this rune should introduce a break.
func (c info) isBreak() bool {
	return c.cccVal() == cccBreak
}

// isLetter returns whether the rune is of break type ALetter, Hebrew_Letter,
// Numeric, ExtendNumLet, or Extend.
func (c info) isLetter() bool {
	ccc := c.cccVal()
	if ccc == cccZero {
		return !c.isCaseIgnorable()
	}
	return ccc != cccBreak

		return fmt.Errorf("invalid name %q, should end with a letter or digit", name)
	}
	return nil
}

func isLetter(c rune) bool {
	return ('A' <= c && c <= 'Z') || ('a' <= c && c <= 'z')
}

func isDigit(c rune) bool {
	return '0' <= c && c <= '9'
}

func isAlphaNumeric(c rune) bool {
	return isLetter(c) || isDigit(c)

func IsControl(r rune) bool {
	if uint32(r) <= MaxLatin1 {
		return properties[uint8(r)]&pC != 0
	}
	// All control characters are < MaxLatin1.
	return false
}

// IsLetter reports whether the rune is a letter (category [L]).
func IsLetter(r rune) bool {
	if uint32(r) <= MaxLatin1 {
		return properties[uint8(r)]&(pLmask) != 0
	}
	return isExcludingLatin(Letter, r)
}

	switch {
	case strings.HasPrefix(t, "<!--"):
		end = "-->"
	case strings.HasPrefix(t, "<?"):
		end = "?>"
	case strings.HasPrefix(t, "<![CDATA["):
		end = "]]>"
	case strings.HasPrefix(t, "<!") && len(t) >= 3 && isLetter(t[2]):
		if 'a' <= t[2] && t[2] <= 'z' {
			// Goldmark and the Dingus only accept <!UPPER> not <!lower>.
			p.corner = true
		}
		end = ">"
	}
	if end != "" {

			return fmt.Errorf("duplicate analyzer: %s", a.Name)
		}
		color[a] = finished
	}

	return nil
}

func validIdent(name string) bool {
	for i, r := range name {
		if !(r == '_' || unicode.IsLetter(r) || i > 0 && unicode.IsDigit(r)) {
			return false
		}
	}
	return name != ""
}

type CycleInRequiresGraphError struct {
	AnalyzerNames map[string]bool
}

	}

	fmt.Println()
	s.Init(strings.NewReader(src))
	s.Filename = "percent"

	// treat leading '%' as part of an identifier
	s.IsIdentRune = func(ch rune, i int) bool {
		return ch == '%' && i == 0 || unicode.IsLetter(ch) || unicode.IsDigit(ch) && i > 0
	}

	for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
		fmt.Printf("%s: %s\n", s.Position, s.TokenText())
	}

	// Output:
	// default:1:1: %
	// default:1:2: var1