| definition: |
unionWith :: Ord k => (a -> a -> a)
-> Map k a -> Map k a -> Map k a
unionWith _ Tip m2 = m2
unionWith _ m1@(Bin _ _ _ _ _) Tip = m1
unionWith combiner (Bin split_key1 a1 _ left1 right1) m2@(Bin _ _ _ _ _)
= mkVBalBranch split_key1 new_a
(unionWith combiner left1 lts)
(unionWith combiner right1 gts)
where
lts = splitLT m2 split_key1
gts = splitGT m2 split_key1
new_a = case lookup split_key1 m2 of
Nothing -> a1
Just a2 -> combiner a2 a1
|
| demand: |
arguments 3 4 |
| deterministic: |
deterministic operation |
| documentation: |
--- Efficiently combine key/element mappings of two maps into a single one, --- cf. insertWith |
| failfree: |
(_, _, _, _) |
| indeterministic: |
referentially transparent operation |
| infix: |
no fixity defined |
| iotype: |
{(_,_,{Tip},_) |-> _ || (_,_,{Bin},{Tip}) |-> {Bin} || (_,_,{Bin},{Bin}) |-> {Bin}}
|
| name: |
unionWith |
| precedence: |
no precedence defined |
| result-values: |
_ |
| signature: |
Prelude.Ord b => (a -> a -> a) -> Map b a -> Map b a -> Map b a |
| solution-complete: |
operation might suspend on free variables |
| terminating: |
possibly non-terminating |
| totally-defined: |
possibly non-reducible on same data term |