Implement restrictions

[oxalorg]

• Configure such that an error is thrown for restricted functions, probably by using sci deny
• Show a warning for restricted functions - Adding the restrictions data in problem view #14 solves this

[pradeepbishnoi]

To :deny use below example as reference
(eval-string "(first '(1 2 3 4))" {:deny '[inc dec first]})

[pradeepbishnoi]

@borkdude Any suggestion how to convert this into a quote for
Tried few things however not able to convert it.
(first `(~(mapv symbol ["inc" "dec" "last"])))

above expression give a vector with symbol. however want to convert this into a quoted collection for input to :deny.

[borkdude]

Just (mapv symbol ...) should do the trick? Why are you using the backtick?

[pradeepbishnoi]

@borkdude Yes, it does. I over thought on this one and didn't realise that :deny is just needing a vector. Using the backpack I was trying to create a "quoted" statement to pass 🤦

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You're overcomplicating things.
The thing that the user enters is an EDN string.

I wrote this function by trying to solve this problem and as I currently don't yet have a proper branch to merge it from so I post it here:

(defn find-restricted-symbols [restricted-symbol-strings user-input]
  (let [restricted-symbols (set (map symbol restricted-symbol-strings))]
    (->> user-input
         clojure.edn/read-string
         vector
         (clojure.walk/prewalk (fn [form]
                                 (cond (map? form) (concat (keys form) (vals form))
                                       (set? form) (seq form)
                                       :else form)))
         flatten
         set
         (clojure.set/intersection restricted-symbols)
         seq)))

#_(find-restricted-symbols ["flatten" "into"] "(flatten (into [] [[1]]))")
#_(find-restricted-symbols ["flatten" "into"] "#{:my-set-item flatten}")
#_(find-restricted-symbols ["flatten" "into"] "{}")
#_(find-restricted-symbols ["flatten" "into"] "{flatten []}")
#_(find-restricted-symbols ["flatten" "into"] "{flatten {:my-map-key into} }")
#_(find-restricted-symbols ["flatten" "into"] "{flatten {:my-map-key #{[into]}} }")
#_(find-restricted-symbols ["flatten" "into"] "flatten")
#_(find-restricted-symbols ["max" "max-key"] "[max \"max-key\"]")

[borkdude]

What about just using str/includes? on the input string? ;)

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What about just using str/includes? on the input string? ;)

Yes it would work but my function distinguishes between "max-key" and max-key

[borkdude]

No, that would give false positives on locals with that name. The :deny option in SCI was built to do this correctly, only on var names.

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My function would fail on (fn max-key []...), true. And NS resolution wouldn't help.

Would SCI matching recover from this correctly?

[borkdude]

yes

[borkdude]

user=> (sci/eval-string "((fn max-key [] 1))" {:deny '[max-key]})
1
user=> (sci/eval-string "(max-key (fn max-key [] 1))" {:deny '[max-key]})
Execution error (ExceptionInfo) at sci.impl.utils/throw-error-with-location (utils.cljc:41).
max-key is not allowed!

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Should it still evaluate and show the results together with restriction error?

[borkdude]

@Invertisment Maybe we can make restricting a setting like you did for the editor settings. In case an error happens with restrictions, we want to offer the ability to turn that off.

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Do you mean that you would expect to accept range as solution to "implement range" if this kind of option would be false?
I was thinking about simply showing additional message.

Also if restriction check wouldn't be part of evaluator then we could do this check elsewhere.
But yes. If it would be part of evaluator then we would either need to evaluate it twice or only show either an error or result but nothing else.

[borkdude]

Evaluating twice also seems fine, in case the restriction is hit.