46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
package unilex
|
|
|
|
// ScanNumber simplest scanner that accepts decimal int and float.
|
|
func ScanNumber(l *Lexer) bool {
|
|
l.AcceptWhile("0123456789")
|
|
if l.AtStart() {
|
|
// not found any digit
|
|
return false
|
|
}
|
|
l.Accept(".")
|
|
l.AcceptWhile("0123456789")
|
|
return !l.AtStart()
|
|
}
|
|
|
|
// ScanAlphaNum returns true if next input token contains alphanum sequence that not starts from digit and not contains.
|
|
// spaces or special characters.
|
|
func ScanAlphaNum(l *Lexer) bool {
|
|
digits := "0123456789"
|
|
alpha := "qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM"
|
|
if !l.Accept(alpha) {
|
|
return false
|
|
}
|
|
l.AcceptWhile(alpha + digits)
|
|
return true
|
|
}
|
|
|
|
// ScanQuotedString returns true if next input tokens is quoted string. Can be used with any type of quotes.
|
|
func ScanQuotedString(l *Lexer, quote rune) bool {
|
|
start := l.Pos
|
|
if l.Next() != quote {
|
|
l.Back()
|
|
return false
|
|
}
|
|
for {
|
|
ch := l.Next()
|
|
switch ch {
|
|
case EOF:
|
|
l.Pos = start // Return position to start
|
|
return false // Unclosed quote string?
|
|
case '\\':
|
|
l.Next() // Skip next char
|
|
case quote:
|
|
return true // Closing quote
|
|
}
|
|
}
|
|
}
|