public override AstNode Visit(UnaryOperation node)
{
// Get the expression.
Expression expr = node.GetExpression();
// Visit the expression.
expr.Accept(this);
// Get the expression type.
IChelaType type = expr.GetNodeType();
// Dereference the type.
type = DeReferenceType(type);
node.SetCoercionType(type);
// De-const the type.
type = DeConstType(type);
// Validate the expression type.
switch(node.GetOperation())
{
case UnaryOperation.OpNop:
break;
case UnaryOperation.OpNeg:
if(!type.IsNumber())
Error(node, "expected numeric expression.");
// Use signed integer when negating.
if(type.IsInteger() && !type.IsPlaceHolderType())
{
IntegerType intType = (IntegerType)type;
intType = intType.GetSignedVersion();
if(node.GetCoercionType().IsConstant())
node.SetCoercionType(ConstantType.Create(intType));
else
node.SetCoercionType(intType);
}
break;
case UnaryOperation.OpNot:
if(type != ChelaType.GetBoolType())
Error(node, "expected boolean expression.");
break;
case UnaryOperation.OpBitNot:
if(!type.IsInteger())
Error(node, "expected integer expression.");
break;
default:
Error(node, "Compiler bug, unknown unary operation.");
break;
}
// Set the node type.
node.SetNodeType(node.GetCoercionType());
return node;
}
