void ExpressionChecker::visit( BinaryExpression *exp )
{
Expression *left = exp->getLeftExpression();
Expression *right = exp->getRightExpression();
visit_and_check(left);
visit_and_check(right);
ExpressionType leftType = left->getExpressionType();
ExpressionType rightType = right->getExpressionType();
if (leftType != rightType) {
error = left->getText() + " and " + right->getText() +
" must have the same type\n" +
left->getText() + " has type " + leftType + ", " +
right->getText() + " has type " + rightType;
return;
}
ExpressionOperator op = exp->getOperator();
// by now we already checked that subexpressions have the same type
if (isBooleanOp(op)) {
if (leftType != BOOL_TYPE) {
not_boolean(left->getText());
}
exp->setExpressionType( BOOL_TYPE );
} else if (isRelativeOp(op)) {
if (leftType == BOOL_TYPE) {
set_error(op + " cannot act on boolean expressions " + left->getText() +
" and " + right->getText());
}
exp->setExpressionType( BOOL_TYPE );
} else if (isExactCompareOp(op)) {
// equal works for any type and we have already checked
// that the two subexpressions have the same type
exp->setExpressionType( BOOL_TYPE );
}
// otherwise the type is still no type
}
void ExpressionChecker::visit( UnaryExpression *exp )
{
Expression *subExpression = exp->getSubExpression();
visit_and_check(subExpression);
ExpressionOperator op = exp->getOperator();
ExpressionType type = subExpression->getExpressionType();
if (isNotOp(op) && type != BOOL_TYPE) {
not_boolean(subExpression->getText());
}
// we get the same type of the subexpression
exp->setExpressionType( type );
}
