/// <summary>
/// Process a word.
/// </summary>
/// <param name="lexer"></param>
/// <param name="endState"></param>
/// <returns></returns>
private static RegularState pWord(Lexer lexer, RegularState endState)
{
Token t = lexer.token();
lexer.nextToken();
RegularState result = new RegularState();
RegularTransition transition = new RegularTransition(result, endState);
transition.addLabel(t.ToString());
return(result);
}
/// <summary>
/// Process sequences of words and subexpressions
/// </summary>
/// <param name="lexer"></param>
/// <param name="endState"></param>
/// <returns></returns>
private static RegularState pSeq(Lexer lexer, RegularState endState)
{
RegularState result = null;
RegularState lhs = null;
while (lexer.token().type == Token.WORD || lexer.token().type == Token.NOT ||
lexer.token().type == Token.PLEFT || lexer.token().type == Token.DOT)
{
RegularState rhs;
if (lexer.token().type == Token.WORD)
{
rhs = pWord(lexer, endState);
}
else if (lexer.token().type == Token.DOT)
{
lexer.nextToken();
rhs = new RegularState();
RegularTransition transition = new RegularTransition(rhs, endState);
transition.addLabel(RegularTransition.WILDCARD);
multTransform(rhs, lexer, endState);
}
else if (lexer.token().type == Token.NOT)
{
// ![word1,word2,word3,word4,...]
rhs = new RegularState();
RegularTransition transition = new RegularTransition(rhs, endState);
transition.setNegation(true);
lexer.nextToken();
while (lexer.token().type == Token.WORD)
{
transition.addLabel(lexer.token().ToString());
lexer.nextToken();
if (lexer.token().type == Token.COMMA)
{
lexer.nextToken();
}
}
if (lexer.token().type != Token.SRIGHT)
{
throw new PatternParseException(String.Format("Missing right square bracket at #%d", lexer
.charPos()));
}
lexer.nextToken();
multTransform(rhs, lexer, endState);
}
else
{
rhs = pSubexp(lexer, endState);
}
if (result == null)
{
// first item in the sequence is the return value;
result = rhs;
}
if (lhs != null)
{
// link end state of previous item in the list to current
// item
replaceStates(lhs, endState, rhs);
}
lhs = rhs;
}
if (lexer.token().type == Token.EOF && result == null)
{
// empty regex
return(endState);
}
if (result == null)
{
throw new PatternParseException(String.Format("Unexpected token '%s' at #%d", lexer.token().text, lexer
.charPos()));
}
return(result);
}