private ExpressionNode ParseSubexpression(int precBound, ExpressionNode left)
{
while (true)
{
int curPrec = precedence[(int)curtok.ID];
if (curPrec < precBound) break;
int associativity = ASSOC_LEFT;
TokenID curOp = curtok.ID;
switch (curOp)
{
case TokenID.Equal:
case TokenID.PlusEqual:
case TokenID.MinusEqual:
case TokenID.StarEqual:
case TokenID.SlashEqual:
case TokenID.PercentEqual:
case TokenID.BAndEqual:
case TokenID.BOrEqual:
case TokenID.BXorEqual:
case TokenID.ShiftLeftEqual:
case TokenID.QuestionQuestion:
associativity = ASSOC_RIGHT;
goto case TokenID.Percent; // "FALL THROUGH"
case TokenID.Greater:
Advance();
if (curtok.ID == TokenID.Greater && curtok.LastCharWasGreater)
{
curOp = TokenID.ShiftRight;
Advance();
}
else if (curtok.ID == TokenID.GreaterEqual && curtok.LastCharWasGreater)
{
curOp = TokenID.ShiftRightEqual;
associativity = ASSOC_RIGHT;
Advance();
}
goto parseBinOp;
case TokenID.Or:
case TokenID.And:
case TokenID.BOr:
case TokenID.BXor:
case TokenID.BAnd:
case TokenID.EqualEqual:
case TokenID.NotEqual:
case TokenID.Less:
case TokenID.LessEqual:
case TokenID.GreaterEqual:
case TokenID.ShiftLeft:
case TokenID.Plus:
case TokenID.Minus:
case TokenID.Star:
case TokenID.Slash:
case TokenID.Percent:
Advance();
parseBinOp: left = new BinaryExpression(curOp, left, ParseSubexpression(curPrec + associativity));
break;
case TokenID.PlusPlus: // postfix
Advance();
left = new PostIncrementExpression(left);
break;
case TokenID.MinusMinus: // postfix
Advance();
left = new PostDecrementExpression(left);
break;
case TokenID.Is:
case TokenID.As:
Advance();
left = new BinaryExpression(curOp, left, ParseType(true));
break;
case TokenID.Question:
{
Advance();
ExpressionNode thenExpr = ParseExpression();
AssertAndAdvance(TokenID.Colon);
left = new ConditionalExpression(left, thenExpr, ParseExpression());
break;
}
case TokenID.LParen: // invocation
Advance();
left = new InvocationExpression(left, ParseArgumentList());
AssertAndAdvance(TokenID.RParen);
break;
case TokenID.LBracket: // element access
Advance();
left = new ElementAccessExpression(left, ParseExpressionList());
AssertAndAdvance(TokenID.RBracket);
break;
case TokenID.Dot: // member access
case TokenID.MinusGreater:
left = ParseMemberAccess(left);
break;
default:
ReportError("Unexpected token", curtok);
return left;
}
}
return left;
}
public virtual object VisitInvocationExpression(InvocationExpression invocationExpression, object data)
{
stackMap.Push(invocationExpression);
invocationExpression.LeftSide.AcceptVisitor(this, data);
invocationExpression.ArgumentList.AcceptVisitor(this, data);
stackMap.Pop();
return null;
}