public override object Visit(EachLoopAstNode node)
{
// First check that the loop variable doesn't already exist
if (SymbolTable.Has(node.LoopVariableNode.Name))
{
throw new Exception($"Loop variable {node.LoopVariableNode.Name} at position {node.LoopVariableNode.Token.Position} is already defined!");
}
// Verify that the enumerable variable exists and is an enumerable
var enumerable = SymbolTable.Get(node.EnumerableVariableNode.Name);
var type = enumerable.GetType();
if (!typeof(IEnumerable).IsAssignableFrom(type))
{
throw new Exception($"{node.EnumerableVariableNode.Name} is not an Enumerable object at position {node.EnumerableVariableNode.Token.Position}");
}
// Concatenate output from the loop body
var stringBuilder = new StringBuilder();
foreach (var item in (IEnumerable)enumerable)
{
SymbolTable.Set(node.LoopVariableNode.Name, item);
stringBuilder.Append(node.LoopBodyNode.Accept(this));
}
return(stringBuilder.ToString());
}
public virtual object Visit(EachLoopAstNode node)
{
return(null);
}
