func lexNewline(l *lex.Lexer) lex.StateFn {
l.AcceptRun(indent)
if l.AcceptRun(lineend) == 0 {
l.Errorf("lexer error - missing expected newline")
} else {
l.Emit(tokNewline)
}
return nil
}
func lexBlankLine(l *lex.Lexer) lex.StateFn {
l.AcceptRun(indent)
l.Ignore()
if l.AcceptRun(lineend) == 0 {
l.Errorf("unexpected non-blank line at line %v", l.LineNumber())
return lexSkipLine
}
l.Ignore()
return nil
}
func lexAt(l *lex.Lexer) lex.StateFn {
if n := l.AcceptRun(at); n > 2 {
l.Errorf("invalid token on line %v", l.LineNumber())
return lexSkipLine
} else if n == 1 {
l.Emit(tokAt)
} else if n == 2 {
l.Emit(tokAtAt)
}
return nil
}
// lexStart looks for a comment or a transaction, it emits everything
// inbetween as tokText
func lexStart(l *lex.Lexer) lex.StateFn {
switch r := l.Peek(); {
case string(r) == meta:
l.Push(lexStart)
return lexMeta
case unicode.IsDigit(r):
l.Push(lexStart)
return lexTrans
case isSpace(r) || isNewline(r):
l.Push(lexStart)
return lexBlankLine
case r == lex.EOF:
l.Emit(lex.TokEOF)
return nil
default:
l.Errorf("unexpected text on line %v", l.LineNumber())
l.Push(lexStart)
return lexSkipLine
}
}
func lexDate(l *lex.Lexer) lex.StateFn {
fail := false
if l.AcceptRun(digit) == 0 {
fail = true
} else if !l.Accept("/") {
fail = true
} else if l.AcceptRun(digit) == 0 {
fail = true
} else if !l.Accept("/") {
fail = true
} else if l.AcceptRun(digit) == 0 {
fail = true
}
if fail {
l.AcceptRunNot(whitespace + meta)
l.Errorf("invalid date on line %v", l.LineNumber())
l.Ignore()
} else {
l.Emit(tokDate)
}
return nil
}