public IExpression Parse(Parser parser, IExpression left, Token token)
{
var thenArm = parser.ParseExpression();
parser.Consume(TokenType.Colon);
var elseArm = parser.ParseExpression(Precedence.Conditional - 1);
return new ConditionalExpression(left, thenArm, elseArm);
}
public IExpression Parse(Parser parser, IExpression left, Token token)
{
// To handle right-associative operators like "^", we allow a slightly
// lower precedence when parsing the right-hand side. This will let a
// parselet with the same precedence appear on the right, which will then
// take *this* parselet's result as its left-hand argument.
var right = parser.ParseExpression(_precedence - (_right ? 1 : 0));
return new OperatorExpression(left, _operator, right);
}
public IExpression Parse(Parser parser, IExpression left, Token token)
{
var right = parser.ParseExpression((int)Precedence.Assignment - 1);
if (!(left is NameExpression))
{
throw new ParseException("The left-hand side of an assignment must be a name.");
}
var name = ((NameExpression)left).Name;
return new AssignExpression(name, right);
}
public IExpression Parse(Parser parser, IExpression left, Token token)
{
// Parse the comma-separated arguments until we hit, ")".
var args = new List<IExpression>();
// There may be no arguments at all.
if (!parser.Match(TokenType.RightParen))
{
do
{
args.Add(parser.ParseExpression());
}
while (parser.Match(TokenType.Comma));
parser.Consume(TokenType.RightParen);
}
return new CallExpression(left, args);
}
public IExpression Parse(Parser parser, Token token)
{
return new NameExpression(token.Value);
}
public IExpression Parse(Parser parser, Token token)
{
var expression = parser.ParseExpression();
parser.Consume(TokenType.RightParen);
return expression;
}
public IExpression Parse(Parser parser, IExpression left, Token token)
{
return new PostfixExpression(left, _operator);
}