public void EXPRESSION(ParseNode node)
{
var expressionNode = new ParseNode("expr");
node.AddChild(expressionNode);
while (_lookahead.Type != TokenType.CLOSE_PARENTHESIS && _lookahead.Type != TokenType.EOF)
{
switch (_lookahead.Type)
{
case TokenType.OPEN_PARENTHESIS:
Match(TokenType.OPEN_PARENTHESIS);
EXPRESSION(expressionNode);
Match(TokenType.CLOSE_PARENTHESIS);
continue;
case TokenType.IDENTIFIER:
IDENTIFIER(expressionNode);
continue;
case TokenType.OPERATOR:
OPERATOR(expressionNode);
continue;
case TokenType.VALUE:
VALUE(expressionNode);
continue;
default:
throw new Exception("Unexpected token, found " + _lookahead.Type);
}
}
}
public void IDENTIFIER(ParseNode node)
{
node.AddChild(new ParseNode("id", _lookahead.Value));
Match(TokenType.IDENTIFIER);
}
public void OPERATOR(ParseNode node)
{
node.AddChild(new ParseNode("op", _lookahead.Value));
Match(TokenType.OPERATOR);
}
public void VALUE(ParseNode node)
{
node.AddChild(new ParseNode("val", _lookahead.Value));
Match(TokenType.VALUE);
}
