I try to port some function that search a value of primitive type through a
tree and return null if the value was not found.
I just realized I cannot use the keyword null.
What strategy should I use to achieve this in ats ?
thanks 
Is there a reason why the option-type is not suitable?
If you post some pseudo code, I will probably be able to suggest something.
Try checking out the option type (inspired by SML and friends). I believe
there is some example code using it on these forums, the the code in the
ATS book and elsewhere may be better.
I didn’t either; my background is mostly C, Python, and MATLAB. So needless to say I’m still getting used to a lot of functional features, but usually I am pleasantly surprised.
yes, thanks a lot
sorry for the dumb question, but I dont have an SML background.
Mine is rather dynamic language such as Common lisp and Scheme