Re: [Haskell-cafe] Help wanted: Lazy multiway zipper with mismached intervals

From: ChrisK Rene de Visser wrote: Does a single list have only disjoint intervals? Yes. The lists are strictly increasing Doing this for two lists with a recursive function is easy. There being an output element whenever the intervals of the two input lists overlap. Yes, I have done this.

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However the combination of merging multiple lists together, and ignoring a list in the case it is not needed by the computation leads to very messy code.

Do mean multiple as in "at least three"? Yes

If so, then what do have an output element only if all three or more input elements overlap, or do you have an output element when at least two input elements overlap?

That can depend on the values (payloads) per entry. For example I might have a selector operator and one of the lists steers from which of the other lists I should take the value for that interval. I think a continuation per list would provide a nice solution. But I don't know how to do that, and it might be horribly ineffecient? Rene.