The task doesn't seem too different from that done by File::Find or any other treewalking program.

How about keeping partial solutions on a stack? Backtrack with pop, go forward with push. You could implement that with recursive calls and let the stack be local and mainly implicit in the return conditions.

I don't know if that could be called functional programming. It is pretty much how functional languages work under the hood.

After Compline,
Zaxo

In reply to Re: Logic programming without using the RE engine as a crutch by Zaxo
in thread Logic programming without using the RE engine as a crutch by diotalevi

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