public ParseException(Token token, string error)
: this(token?.File ?? string.Empty, token?.Line ?? -1, token?.Column ?? -1, error)
{
}
private void MoveToNextToken()
{
// If any tokens were pushed back to the lexer, move trough these first.
if (_pushedTokens.Count > 0)
{
Current = _pushedTokens.Pop();
return;
}
// Find the first matching token type.
foreach (var tokenData in _tokenTypes)
{
var match = tokenData.Pattern.Match(_input, _caretPosition);
if (match.Success)
{
Current = new Token(tokenData.Type, match.Groups[tokenData.ContentGroup].Value, _file, _line,
_column);
MoveCaret(match.Groups[0].Length);
SkipWhitespace();
return;
}
}
// If no token type was found, the character at the caret is a token.
var token = _input.Substring(_caretPosition, 1);
Current = new Token(TokenType.Token, token, _file, _line, _column);
MoveCaret(1);
SkipWhitespace();
}
/// <summary>
/// Pushes the specified token.
/// </summary>
/// <param name="token">The token.</param>
public void Push(Token token)
{
if (token == null) throw new ArgumentNullException(nameof(token));
// Push the current token to the stack and set the current token to the pushed token.
if (Current != null)
_pushedTokens.Push(Current);
Current = token;
}
/// <summary>
/// Sets the enumerator to its initial position, which is before the first element in the collection.
/// </summary>
public void Reset()
{
_column = 1;
_line = 1;
_caretPosition = 0;
_pushedTokens.Clear();
Current = null;
SkipWhitespace();
}
/// <summary>
/// Advances the enumerator to the next element of the collection.
/// </summary>
/// <returns>
/// true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of
/// the collection.
/// </returns>
public bool MoveNext()
{
if (_caretPosition >= _input.Length && _pushedTokens.Count == 0)
{
Current = null;
return false;
}
MoveToNextToken();
return true;
}