/// <summary>
/// Reads a relational expression.
/// </summary>
/// <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>
/// <param name="parentReference">The parent code part.</param>
/// <param name="unsafeCode">Indicates whether the code being parsed resides in an unsafe code block.</param>
/// <returns>Returns the expression.</returns>
private RelationalExpression GetRelationalExpression(
Expression leftHandSide, ExpressionPrecedence previousPrecedence, Reference<ICodePart> parentReference, bool unsafeCode)
{
Param.AssertNotNull(leftHandSide, "leftHandSide");
Param.Ignore(previousPrecedence);
Param.AssertNotNull(parentReference, "parentReference");
Param.Ignore(unsafeCode);
RelationalExpression expression = null;
var expressionReference = new Reference<ICodePart>();
// Read the details of the expression.
OperatorSymbol operatorToken = this.PeekOperatorToken(parentReference, expressionReference);
Debug.Assert(operatorToken.Category == OperatorCategory.Relational, "Expected a relational operator");
// 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();
this.tokens.Add(operatorToken);
// Get the expression on the right-hand side of the operator.
Expression rightHandSide = this.GetOperatorRightHandExpression(precedence, expressionReference, unsafeCode);
// Create the partial token list for the expression.
CsTokenList partialTokens = new CsTokenList(this.tokens, leftHandSide.Tokens.First, this.tokens.Last);
// Get the expression operator type.
RelationalExpression.Operator type;
switch (operatorToken.SymbolType)
{
case OperatorType.ConditionalEquals:
type = RelationalExpression.Operator.EqualTo;
break;
case OperatorType.NotEquals:
type = RelationalExpression.Operator.NotEqualTo;
break;
case OperatorType.GreaterThan:
type = RelationalExpression.Operator.GreaterThan;
break;
case OperatorType.GreaterThanOrEquals:
type = RelationalExpression.Operator.GreaterThanOrEqualTo;
break;
case OperatorType.LessThan:
type = RelationalExpression.Operator.LessThan;
break;
case OperatorType.LessThanOrEquals:
type = RelationalExpression.Operator.LessThanOrEqualTo;
break;
default:
Debug.Fail("Unexpected operator type");
throw new InvalidOperationException();
}
// Create and return the expression.
expression = new RelationalExpression(partialTokens, type, leftHandSide, rightHandSide);
expressionReference.Target = expression;
}
return expression;
}
/// <summary>
/// Reads a relational expression.
/// </summary>
/// <param name="sourceCode">The file containing the expression.</param>
/// <param name="parentReference">The parent code unit.</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 RelationalExpression GetConditionalPreprocessorEqualityExpression(
SourceCode sourceCode, Reference<ICodePart> parentReference, Expression leftHandSide, ExpressionPrecedence previousPrecedence)
{
Param.AssertNotNull(sourceCode, "sourceCode");
Param.AssertNotNull(parentReference, "parentReference");
Param.AssertNotNull(leftHandSide, "leftHandSide");
Param.Ignore(previousPrecedence);
RelationalExpression expression = null;
this.AdvanceToNextConditionalDirectiveCodeSymbol(parentReference);
Symbol firstSymbol = this.symbols.Peek(1);
if (firstSymbol == null)
{
throw new SyntaxException(sourceCode, firstSymbol.LineNumber);
}
var expressionReference = new Reference<ICodePart>();
// Create the operator symbol.
OperatorType type;
OperatorCategory category;
GetOperatorType(firstSymbol, out type, out category);
OperatorSymbol operatorToken = new OperatorSymbol(
firstSymbol.Text, category, type, firstSymbol.Location, expressionReference, this.symbols.Generated);
// 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();
this.tokens.Add(operatorToken);
// Get the expression on the right-hand side of the operator.
Expression rightHandSide = this.GetNextConditionalPreprocessorExpression(sourceCode, precedence);
if (rightHandSide == null)
{
throw new SyntaxException(sourceCode, operatorToken.LineNumber);
}
// Create the partial token list for the expression.
CsTokenList partialTokens = new CsTokenList(this.tokens, leftHandSide.Tokens.First, this.tokens.Last);
// Get the expression operator type.
RelationalExpression.Operator relationalType;
switch (operatorToken.SymbolType)
{
case OperatorType.ConditionalEquals:
relationalType = RelationalExpression.Operator.EqualTo;
break;
case OperatorType.NotEquals:
relationalType = RelationalExpression.Operator.NotEqualTo;
break;
default:
throw new SyntaxException(sourceCode, operatorToken.LineNumber);
}
// Create and return the expression.
expression = new RelationalExpression(partialTokens, relationalType, leftHandSide, rightHandSide);
expressionReference.Target = expression;
}
return expression;
}