F# Split list into sublists based on comparison of adjacent elements

Question

I\'ve found this question on hubFS, but that handles a splitting criteria based on individual elements. I\'d like to split based on a comparison of adjacent elements, so the

Answer 1

I like answers provided by @Joh and @Johan as these solutions seem to be most idiomatic and straightforward. I also like an idea suggested by @Shooton. However, each solution had their own drawbacks.
I was trying to avoid:

• Reversing lists
• Unsplitting and joining back the temporary results
• Complex match instructions
• Even Seq.pairwise appeared to be redundant
• Checking list for emptiness can be removed in cost of using Unchecked.defaultof<_> below

Here's my version:

let splitWhen f src =
    if List.isEmpty src then [] else
    src
    |> List.foldBack
        (fun el (prev, current, rest) ->
            if f el prev
            then el , [el]          , current :: rest
            else el , el :: current , rest
        )
        <| (List.head src, [], [])               // Initial value does not matter, dislike using Unchecked.defaultof<_>
    |> fun (_, current, rest) -> current :: rest // Merge temporary lists
    |> List.filter (not << List.isEmpty)         // Drop tail element