func lexG8(x *lex8.Lexer) *lex8.Token {
r := x.Rune()
if x.IsWhite(r) {
panic("incorrect token start")
}
switch r {
case '\n':
x.Next()
return x.MakeToken(Endl)
case '"':
return lex8.LexString(x, String, '"')
case '\'':
return lex8.LexString(x, Char, '\'')
}
if lex8.IsDigit(r) {
return lexNumber(x)
} else if isLetter(r) {
return lexIdent(x)
}
// always make progress at this point
x.Next()
t := lexOperator(x, r)
if t != nil {
return t
}
x.Errorf("illegal char %q", r)
return x.MakeToken(lex8.Illegal)
}
func lexAsm8(x *lex8.Lexer) *lex8.Token {
r := x.Rune()
if x.IsWhite(r) {
panic("incorrect token start")
}
switch r {
case '\n':
x.Next()
return x.MakeToken(Endl)
case '{':
x.Next()
return x.MakeToken(Lbrace)
case '}':
x.Next()
return x.MakeToken(Rbrace)
case '/':
x.Next()
return lex8.LexComment(x)
case '"':
return lex8.LexString(x, String, '"')
}
if isOperandChar(r) {
return lexOperand(x)
}
x.Errorf("illegal char %q", r)
x.Next()
return x.MakeToken(lex8.Illegal)
}
func lexIdent(x *lex8.Lexer) *lex8.Token {
r := x.Rune()
if !isLetter(r) {
panic("must start with letter")
}
for {
x.Next()
r := x.Rune()
if !isLetter(r) && !lex8.IsDigit(r) {
break
}
}
ret := x.MakeToken(Ident)
return ret
}
func lexOperand(x *lex8.Lexer) *lex8.Token {
if !isOperandChar(x.Rune()) {
panic("incorrect operand start")
}
for {
x.Next()
if x.Ended() || !isOperandChar(x.Rune()) {
break
}
}
ret := x.MakeToken(Operand)
if isKeyword(ret.Lit) {
ret.Type = Keyword
}
return ret
}
func lexNumber(x *lex8.Lexer) *lex8.Token {
// TODO: lex floating point as well
start := x.Rune()
if !lex8.IsDigit(start) {
panic("not starting with a number")
}
x.Next()
r := x.Rune()
if start == '0' && r == 'x' {
x.Next()
for lex8.IsHexDigit(x.Rune()) {
x.Next()
}
} else {
for lex8.IsDigit(x.Rune()) {
x.Next()
}
}
return x.MakeToken(Int)
}
func lexOperator(x *lex8.Lexer, r rune) *lex8.Token {
switch r {
case ';':
return x.MakeToken(Semi)
case '{', '}', '(', ')', '[', ']', ',':
/* do nothing */
case '/':
r2 := x.Rune()
if r2 == '/' || r2 == '*' {
return lex8.LexComment(x)
} else if r2 == '=' {
x.Next()
}
case '+', '-', '&', '|':
r2 := x.Rune()
if r2 == r || r2 == '=' {
x.Next()
}
case '*', '%', '^', '=', '!', ':':
r2 := x.Rune()
if r2 == '=' {
x.Next()
}
case '.':
r2 := x.Rune()
if r2 == '.' {
x.Next()
r3 := x.Rune()
if r3 != '.' {
x.Errorf("expect ..., but see ..")
return x.MakeToken(Operator)
}
x.Next()
}
case '>', '<':
r2 := x.Rune()
if r2 == r {
x.Next()
r3 := x.Rune()
if r3 == '=' {
x.Next()
}
} else if r2 == '=' {
x.Next()
}
default:
return nil
}
return x.MakeToken(Operator)
}