object IVisitor <object> .visit(IdNode node)
{
string type = SymbolTable.lookupType(node.value);
string value = SymbolTable.lookup(node.value);
if (value != null)
{
node.type = type;
return(node.type);
}
else
{
new SemanticError(node, "Semantic Error: " + node.value + " does not exist in this context.");
}
return(null);
}
public void checkOperationIsAllowed(Node operation, Node left, Node right)
{
if (SymbolTable.lookup(left.value) == null || SymbolTable.lookup(right.value) == null)
{
return; // return as one of the children does not exist
}
bool allowed = false;
foreach (var rule in allowedOperations)
{
if (operation.value.Equals(rule[0]) & left.type.Equals(rule[1]) & right.type.Equals(rule[2]))
{
allowed = true;
}
}
if (!allowed)
{
new SemanticError(operation, "Semantic Error: Operation not allowed: " + left.type + " " + operation.value + " " + right.type);
}
}
object IVisitor <object> .visit(IdNode node)
{
return(SymbolTable.lookup(node.value));
}