Problem Statement

Split a (character) string into comma (plus a blank) delimited strings based on a change of character   (left to right). Show the output here   (use the 1st example below).

Blanks should be treated as any other character   (except they are problematic to display clearly).   The same applies to commas.

For instance, the string: should be split and show:

Let's start with the solution:

open System.Text.RegularExpressions
let splitRuns s = Regex("""(.)\1*""").Matches(s) |> Seq.cast<Match> |> Seq.map (fun m -> m.Value) |> Seq.toList
printfn "%A" (splitRuns """gHHH5YY++///\""")