private ExpressionNode ParseSubexpression(int precBound, ExpressionNode left)
{
while (true)
{
int curPrec = _precedence[(int)_curtok.TokenId];
if (curPrec < precBound)
{
break;
}
int associativity = ASSOC_LEFT;
TokenId curOp = _curtok.TokenId;
switch (curOp)
{
case TokenId.Equal:
case TokenId.PlusEqual:
case TokenId.MinusEqual:
case TokenId.StarEqual:
case TokenId.SlashEqual:
case TokenId.PercentEqual:
case TokenId.QuestionQuestion:
{
associativity = ASSOC_RIGHT;
goto case TokenId.Percent; // "FALL THROUGH"
}
case TokenId.Greater:
case TokenId.Or:
case TokenId.And:
case TokenId.EqualEqual:
case TokenId.NotEqual:
case TokenId.Less:
case TokenId.LessEqual:
case TokenId.GreaterEqual:
case TokenId.Plus:
case TokenId.Minus:
case TokenId.Star:
case TokenId.Slash:
case TokenId.Percent:
{
Advance();
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.Question:
{
Advance();
ExpressionNode node = ParseExpression();
AssertAndAdvance(TokenId.Colon);
left = new ConditionalExpression(left, node, 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:
left = ParseMemberAccess(left);
break;
default:
throw new ParseException("Unexpected token");
}
}
return(left);
}
private ExpressionNode ParseSubexpression(int precBound, ExpressionNode left)
{
while (true)
{
int curPrec = _precedence[(int)_curtok.TokenId];
if (curPrec < precBound) break;
int associativity = ASSOC_LEFT;
TokenId curOp = _curtok.TokenId;
switch (curOp)
{
case TokenId.Equal:
case TokenId.PlusEqual:
case TokenId.MinusEqual:
case TokenId.StarEqual:
case TokenId.SlashEqual:
case TokenId.PercentEqual:
case TokenId.QuestionQuestion:
{
associativity = ASSOC_RIGHT;
goto case TokenId.Percent; // "FALL THROUGH"
}
case TokenId.Greater:
case TokenId.Or:
case TokenId.And:
case TokenId.EqualEqual:
case TokenId.NotEqual:
case TokenId.Less:
case TokenId.LessEqual:
case TokenId.GreaterEqual:
case TokenId.Plus:
case TokenId.Minus:
case TokenId.Star:
case TokenId.Slash:
case TokenId.Percent:
{
Advance();
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.Question:
{
Advance();
ExpressionNode node = ParseExpression();
AssertAndAdvance(TokenId.Colon);
left = new ConditionalExpression(left, node, 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:
left = ParseMemberAccess(left);
break;
default:
throw new ParseException("Unexpected token");
}
}
return left;
}
