Proposal: add 'findLess' and variants to containers
fox at ucw.cz
Sat Feb 18 11:46:51 CET 2012
> Thanks for the benchmark. In light of this and your other arguments I
> think we should add the functions. Lets settle on the names. I
> currently dislike that we have 'lookup' and 'findDefault' (which is
> lookup with a default value.) We should agree on a principle for when
> we use the two words.
We should definitely settle on the names.
At some point I thought maybe we could add just these two functions:
predecessor :: Ord a => a -> Set a -> Maybe a
successor :: Ord a => a -> Set a -> Maybe a
These functions work like findLess, findGreater, i.e., they return
a strict predecessor or successor of a given key. The key does not need
to exist in the set/map.
Are there any good use cases for findLessEqual/findGreaterEqual,
instead of calling lookup and if it fails, call predecessor/successor?
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