feat(slice): add SplitBy function to split slices based on an iteratee

[kilianpaquier]

Purpose

Add SplitBy(collection []T, predicate func(item T, index int) bool) ([]T, []T) to slice.go features.

A little more intuitive than PartitionBy when trying to split a slice in two slices.

[samber]

Some people might want to split in 3 lists, 4 lists, 5 lists...

I suppose a PartitionBy[T, bool](...) map[bool][]T would be simpler.

[kilianpaquier]

Hi @samber, right, it would allow to have multiple partitions while having a better accessibility than:

p1 := partitions[0]
p2 := partitions[1]

But PartitionBy is already used, could SplitBy still be acceptable ? Or do you have a better name in mind ?

[kilianpaquier]

GroupBy should do the job with this point of view !

[samber]

You can use lo.FilterReject that does a similar job.