public virtual Expression visit(PropertyExpression expression)
{
expression.leftExpression.visitExpression(this);
write("[");
expression.rightExpression.visitExpression(this);
write("]");
return(expression);
}
/**
* The grammar for the 'new' keyword is a little complicated. The keyword
* 'new' can occur in either a NewExpression (where its not followed by
* an argument list) or in MemberExpresison (where it is followed by an
* argument list). The intention seems to be that an argument list should
* bind to any unmatched 'new' keyword to the left in the same expression
* if possible, otherwise an argument list is taken as a call expression.
*
* Since the rest of the productions for NewExpressions and CallExpressions
* are similar we roll these two into one routine with a parameter to
* indicate whether we're currently parsing a 'new' expression or not.
*
* @param newFlag if we're currently parsing a 'new' expression
* @return an expression
*/
private Expression parseMemberExpression(bool newFlag) {
Expression expression;
// new expressions are right associative
if (nextToken == Token.KEYWORD_NEW) {
Expression name;
readToken(Token.KEYWORD_NEW);
name = parseMemberExpression(true);
if (nextToken == Token.OPERATOR_OPENPAREN) {
Expression[] arguments = parseArgumentList();
expression = new NewExpression(name, arguments);
} else {
expression = new NewExpression(name, null);
}
} else if (nextToken == Token.KEYWORD_FUNCTION) {
expression = parseFunctionLiteral(false);
} else {
expression = parsePrimaryExpression();
}
// call expressions are left associative
while (true) {
if (!newFlag && nextToken == Token.OPERATOR_OPENPAREN) {
Expression[] arguments = parseArgumentList();
expression = new CallExpression(expression, arguments);
} else if (nextToken == Token.OPERATOR_OPENSQUARE) {
readToken(Token.OPERATOR_OPENSQUARE);
Expression property = parseExpression(true);
readToken(Token.OPERATOR_CLOSESQUARE);
expression = new PropertyExpression(expression, property);
} else if (nextToken == Token.OPERATOR_DOT) {
// transform x.bar to x["bar"]
readToken(Token.OPERATOR_DOT);
Identifier identifier = parseIdentifier();
expression = new PropertyExpression(expression, new StringLiteral(identifier.str));
} else {
return expression;
}
}
}
public virtual Expression visit(PropertyExpression expression)
{
write("property");
return(expression);
}