/// <summary>
/// Reads a conditional logical expression.
/// </summary>
/// <param name="parentProxy">Represents the parent item.</param>
/// <param name="leftHandSide">The expression on the left hand side of the operator.</param>
/// <param name="previousPrecedence">The precedence of the expression just before this one.</param>
/// <returns>Returns the expression.</returns>
private ConditionalLogicalExpression GetConditionalPreprocessorAndOrExpression(
CodeUnitProxy parentProxy, Expression leftHandSide, ExpressionPrecedence previousPrecedence)
{
Param.AssertNotNull(parentProxy, "parentProxy");
Param.AssertNotNull(leftHandSide, "leftHandSide");
Param.Ignore(previousPrecedence);
ConditionalLogicalExpression expression = null;
this.AdvanceToNextConditionalDirectiveCodeSymbol(parentProxy);
var expressionProxy = new CodeUnitProxy(this.document);
// Create the operator symbol.
OperatorSymbolToken operatorToken = this.PeekOperatorSymbolToken();
// Check the precedence of the operators to make sure we can gather this statement now.
ExpressionPrecedence precedence = GetOperatorPrecedence(operatorToken.SymbolType);
if (CheckPrecedence(previousPrecedence, precedence))
{
// Add the operator token to the document and advance the symbol manager up to it.
this.symbols.Advance();
expressionProxy.Children.Add(operatorToken);
// Get the expression on the right-hand side of the operator.
Expression rightHandSide = this.GetNextConditionalPreprocessorExpression(this.document, expressionProxy, precedence);
if (rightHandSide == null)
{
throw new SyntaxException(this.document, operatorToken.LineNumber);
}
// Get the expression operator type.
switch (operatorToken.SymbolType)
{
case OperatorType.ConditionalAnd:
expression = new ConditionalAndExpression(expressionProxy, leftHandSide, rightHandSide);
break;
case OperatorType.ConditionalOr:
expression = new ConditionalOrExpression(expressionProxy, leftHandSide, rightHandSide);
break;
default:
throw new SyntaxException(this.document, operatorToken.LineNumber);
}
parentProxy.Children.Add(expression);
}
return(expression);
}
/// <summary>
/// Initializes the contents of the expression.
/// </summary>
private void Initialize()
{
this.leftHandSide.Value = this.FindFirstChildExpression();
if (this.leftHandSide.Value == null)
{
throw new SyntaxException(this.Document, this.LineNumber);
}
OperatorSymbolToken o = this.leftHandSide.Value.FindNextSibling <OperatorSymbolToken>();
if (o == null)
{
throw new SyntaxException(this.Document, this.LineNumber);
}
this.rightHandSide.Value = o.FindNextSiblingExpression();
if (this.rightHandSide.Value == null)
{
throw new SyntaxException(this.Document, this.LineNumber);
}
}
