public BinaryExpression(ExpressionNodeBase lvalue, Operator oper, ExpressionNodeBase rvalue)
: base(lvalue.Location, rvalue.Location)
{
this.LeftValue = lvalue;
this.RightValue = rvalue;
this.Operator = oper;
}
private ExpressionNodeBase ParseExpression(ExpressionContext context)
{
if(!isNextTokenAValidForFirstTokenInExpression())
_errorCollector.UnexpectedToken(_lexer.NextToken());
ExpressionNodeBase retval;
Stack<AstNodeBase> expStack = new Stack<AstNodeBase>();
Stack<Operator> operatorStack = new Stack<Operator>();
int parenCount = 0;
Token currToken = _lexer.PeekToken();
HappySourceLocation startLocation = currToken.Location;
Action<Operator> insertOperatorAndUpdateStacks = oper =>
{
while (operatorStack.Count > 0 &&
operatorStack.Peek().PrecedenceLevel >= oper.PrecedenceLevel)
expStack.Push(operatorStack.Pop());
operatorStack.Push(oper);
};
if (currToken.HappyTokenKind == HappyTokenKind.LiteralNull)
{
_lexer.NextToken();
retval = this.PromoteToExpression(currToken);
}
else
{
//Rules for existing the while loop below:
// Always stop parsing when a keyword other than new is encountered.
// If the languageContext is argument list, stop parsing when "," or ")" that is not matched by a corresponding "(" is encountered
// if the languageContext is nested parens, stop parsing when ")" that is not matched by a corresponding "(" is encountered
// if the languageContext is new statement, stop parsing when "(" is encountered
while (
(!currToken.IsKeyword || currToken.HappyTokenKind == HappyTokenKind.KeywordNew)
&& !(context == ExpressionContext.ArgumentList && currToken.HappyTokenKind == HappyTokenKind.Comma)
&& !((context == ExpressionContext.NestedParens || context == ExpressionContext.ArgumentList) && parenCount == 0 && currToken.HappyTokenKind == HappyTokenKind.OperatorCloseParen)
&& !(context == ExpressionContext.Indexer && (currToken.HappyTokenKind == HappyTokenKind.OperatorCloseBracket || currToken.HappyTokenKind == HappyTokenKind.Comma)))
{
//Check exit conditions first:
bool lastWasArithOperator;
_lexer.NextToken();
if (currToken.IsOperator)
{
lastWasArithOperator = false;
switch(currToken.HappyTokenKind)
{
case HappyTokenKind.OperatorOpenParen:
parenCount++;
break;
case HappyTokenKind.OperatorCloseParen:
parenCount--;
if (parenCount < 0)
{
HappySourceLocation location = HappySourceLocation.Merge(startLocation, this._lexer.PeekToken().Location);
this._errorCollector.MismatchedCloseParen(location);
throw new AbortParseException(location);
}
break;
case HappyTokenKind.OperatorOpenBracket:
List<ExpressionNodeBase> arguments = new List<ExpressionNodeBase> { this.ParseExpression(ExpressionContext.Indexer) };
while (this.EatNextTokenIf(HappyTokenKind.Comma))
arguments.Add(this.ParseExpression(ExpressionContext.Indexer));
var endsAt = this.Expect(HappyTokenKind.OperatorCloseBracket, "]").Location;
var indexOperator = new Operator(currToken);
insertOperatorAndUpdateStacks(indexOperator);
expStack.Push(new ArgumentList(HappySourceLocation.Merge(currToken.Location, endsAt), arguments.ToArray()));
break;
default:
lastWasArithOperator = true;
Operator oper = new Operator(currToken) { PrecedenceLevelModifier = parenCount * Operator.PrecedenceModifierStep };
insertOperatorAndUpdateStacks(oper);
break;
}
}
else if(currToken.HappyTokenKind == HappyTokenKind.KeywordNew)
{
Expect(HappyTokenKind.OperatorOpenParen, "(");
ExpressionNodeBase exp = this.ParseExpression(ExpressionContext.ArgumentList);
List<ExpressionNodeBase> constructorArgs = new List<ExpressionNodeBase>();
Token commaOrCloseParen = Expect(HappyTokenKind.OperatorCloseParen, HappyTokenKind.Comma, MiscMessages.CommaOrCloseParen);
if (commaOrCloseParen.HappyTokenKind == HappyTokenKind.Comma)
do
{
constructorArgs.Add(this.ParseExpression(ExpressionContext.ArgumentList));
commaOrCloseParen = this.Expect(HappyTokenKind.Comma, HappyTokenKind.OperatorCloseParen, MiscMessages.CommaOrCloseParen);
} while (commaOrCloseParen.HappyTokenKind != HappyTokenKind.OperatorCloseParen);
ExpressionNodeBase newExpression = new NewObjectExpression(currToken.Location, commaOrCloseParen.Location, exp, constructorArgs.ToArray());
expStack.Push(newExpression);
lastWasArithOperator = false;
}
else
{
expStack.Push(this.PromoteToExpression(currToken));
lastWasArithOperator = false;
}
currToken = _lexer.PeekToken();
if (!lastWasArithOperator && !currToken.IsOperator && parenCount <= 0)
break;
}
if (parenCount > 0)
{
HappySourceLocation location = HappySourceLocation.Merge(startLocation, currToken.Location);
_errorCollector.MismatchedOpenParen(location);
throw new AbortParseException(location);
}
while (operatorStack.Count > 0)
expStack.Push(operatorStack.Pop());
retval = this.RecurseExp(expStack);
}
return retval;
}
public UnaryExpression(ExpressionNodeBase value, Operator oper)
: base(oper.Location, value.Location)
{
this.Value = value;
this.Operator = oper;
}