@Override
public IValue interpret(Context context) throws PromptoError {
IType srcType = source.check(context);
IType elemType = srcType.checkIterator(context);
return evaluateItemIterator(elemType, context);
}
@Override
public IType check(Context context) throws SyntaxError {
IType srcType = source.check(context);
IType elemType = srcType.checkIterator(context);
return checkItemIterator(elemType, context);
}