/// <summary>
/// Visits the un op node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitUnOpNode(UnOpNode node)
{
// evaluate the operand and then perform the unary operation to it
IProperty operandEval = getEvaluation(node.Operand);
return(unaryOperation(node.Operation, operandEval));
}
/// <summary>
/// Parses the an expression into a node that implements IExpressionContainer interface.
/// </summary>
/// <returns>The next token.</returns>
/// <param name="token">Token.</param>
/// <param name="node">An IExpressionContainer.</param>
private Token ParseExpression(Token token, IExpressionContainer node)
{
Token next;
switch (token.Type)
{
case TokenType.INT_VAL:
case TokenType.STR_VAL:
case TokenType.BOOL_VAL:
case TokenType.PARENTHESIS_LEFT:
case TokenType.ID:
// parse a binary operation
BinOpNode binOp = nodeBuilder.CreateBinOpNode(node, token);
// parse the first operand
next = ParseOperand(token, binOp);
// parse the rest of the operation
return(ParseBinaryOp(next, binOp));
case TokenType.UNARY_OP_LOG_NEG:
// parse a unary operation
UnOpNode unOp = nodeBuilder.CreateUnOpNode(node, token);
// parse the operation, then the operand
next = ParseUnaryOp(token, unOp);
return(ParseOperand(next, unOp));
default:
throw new UnexpectedTokenException(token, TokenType.UNDEFINED, ParserConstants.EXPECTATION_SET_EXPRESSION);
}
}
public UnOpNode CreateUnOpNode(IExpressionContainer parent, Token t)
{
UnOpNode unOp = new UnOpNode(t);
parent.AddExpression(unOp);
return(unOp);
}
/// <summary>
/// Parses a unary operation into a UnOpNode.
/// </summary>
/// <returns>The next token.</returns>
/// <param name="token">Token.</param>
/// <param name="unOp">A UnOpNode.</param>
private Token ParseUnaryOp(Token token, UnOpNode unOp)
{
switch (token.Type)
{
case TokenType.UNARY_OP_LOG_NEG:
unOp.Operation = TokenType.UNARY_OP_LOG_NEG;
unOp.Token = token;
return(scanner.getNextToken(token));
default:
throw new UnexpectedTokenException(token, TokenType.UNARY_OP_LOG_NEG, null);
}
}
/// <summary>
/// Checks the static semantic constraints of an UnOpNode.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitUnOpNode(UnOpNode node)
{
// This is not a statement so it needs not to be actually checked here.
// So, we pass it to the TypeCheckerVisitor instead.
return(node.Accept(this.typeChecker));
}
/// <summary>
/// Visits the un op node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitUnOpNode(UnOpNode node)
{
// return the evaluation of the node using a helper method
return(VisitOperationNode(node));
}
/// <summary>
/// Visits the un op node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitUnOpNode(UnOpNode node)
{
// let the evaluator evaluate this node
return(node.Accept(evaluator));
}