Implement zip.editAt(motion, editfn, loc)

netceteragroup / skele

Architectural framework that assists building data-driven apps with React or React Native.

MIT License

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Implement zip.editAt(motion, editfn, loc) #80

Closed ognen closed 5 years ago

ognen commented 6 years ago

In the module 'zip' implement the function editAt with the signature

editAt :: motionFn -> editFn -> loc -> loc

The function takes a location, performs the specified motion (motionFn), edits the value at that location using the editFn, and then moves back to the starting position, returning the changed tree.

ognen commented 6 years ago

Implementation hint (with a constraint, but I think it should be sufficient):

create a new zipper out of the node in the provided location
perform the motion (the constraint on the motionFn would be that it's downward only)
perform the edit
go to root
take out the node from the root node and use replace to insert it in the original zipper
return result