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exercism fetch sml flatten-array

Flatten Array

Take a nested list and return a single flattened list with all values except nil/null.

The challenge is to write a function that accepts an arbitrarily-deep nested list-like structure and returns a flattened structure without any nil/null values.

For Example

input: [1,[2,3,null,4],[null],5]

output: [1,2,3,4,5]

Hints

You can think of this data structure as a Rose Tree. You are given a data type 'a tree that represents this data structure.

Notes

Loading your exercise implementation in PolyML

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$ poly --use {exercise}.sml

Or:

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$ poly
> use "{exercise}.sml";

Note: You have to replace {exercise}.

Running the tests

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$ poly -q --use test.sml

Feedback, Issues, Pull Requests

The exercism/sml repository on GitHub is the home for all of the Standard ML exercises.

If you have feedback about an exercise, or want to help implementing a new one, head over there and create an issue. We'll do our best to help you!

Source

Interview Question https://reference.wolfram.com/language/ref/Flatten.html

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.