public bool Matches(CondToken expected)
{
if (_token != expected)
{
return(false);
}
Next();
return(true);
}
CondToken ExpectCurrent(CondToken expected)
{
var result = _tokenizer.Token;
if (!_tokenizer.Matches(expected))
{
throw new Exception("unexpected token: " + expected);
}
return(result);
}
private void TakeRegularIdentifier(int c)
{
_builder.Clear();
_builder.Append((char)c);
while (IsIdentifierPart(_buffer.Peek()))
{
_builder.Append((char)_buffer.Next());
}
_value = _builder.ToString();
_token = CondToken.Identifier;
}
private void TakeString(int delim)
{
_builder.Clear();
while (true)
{
var c = _buffer.Next();
if (c == Eof)
{
throw Unexpected(c);
}
if (c == delim)
{
break;
}
_builder.Append((char)c);
}
_value = _builder.ToString();
_token = CondToken.String;
}
public bool Next()
{
while (true)
{
var c = _buffer.Next();
switch (c)
{
case Eof:
_token = CondToken.Eof;
break;
case ' ':
case '\t':
case '\n':
case '\r':
case '\u000C':
_token = CondToken.Space;
continue;
case '\'':
case '"':
TakeString(c);
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
_value = TakeNumber(c);
_token = CondToken.Number;
break;
case '.':
switch (_buffer.Peek())
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
_value = TakeNumber(c);
_token = CondToken.Number;
break;
default:
Unexpected(c);
break;
}
break;
case '=':
if (_buffer.Next() == '=')
{
_token = CondToken.Equal;
}
else
{
Unexpected(c);
}
break;
case '>':
if (_buffer.Peek() == '=')
{
_token = CondToken.GreaterEqual;
_buffer.Next();
}
else
{
_token = CondToken.Greater;
}
break;
case '<':
if (_buffer.Peek() == '=')
{
_token = CondToken.LowerEqual;
_buffer.Next();
}
else
{
_token = CondToken.Lower;
}
break;
case '!':
if (_buffer.Peek() == '=')
{
_token = CondToken.NotEqual;
_buffer.Next();
}
else
{
_token = CondToken.Not;
}
break;
case '(':
_token = CondToken.Lpar;
break;
case ')':
_token = CondToken.Rpar;
break;
case ',':
_token = CondToken.Comma;
break;
default:
if (IsIdentifierStart(c))
{
TakeRegularIdentifier(c);
}
else
{
throw Unexpected(c);
}
break;
}
return(_token != CondToken.Eof);
}
}
