endo

type Endo = EndsWith of string*string| NoEnding of string
EndsWith ("a","b")
NoEnding "a"

let breakEndingO (w:string) ending = if w.EndsWith ending then w.[0..w.Length-ending.Length-1],ending else w,""
let breakEnding (w:string) ending = if w.EndsWith ending then EndsWith (w.[0..w.Length-ending.Length-1],ending) else NoEnding(w)

breakEnding "hellooByInch" "ByInch"
breakEnding "xInch" "Inch"
breakEnding "Inch" "Inch"
breakEnding "x" "Inch"

// now break ending over a collection of possible endings
let breakEndings (w:string) endings = 
  let e = endings |> List.tryFind (fun ending -> w.EndsWith ending)
  //match e with | Some ending -> EndsWith (w.[0..w.Length-ending.Length-1],ending) | None -> NoEnding w
  match e with | Some ending -> w.[0..w.Length-ending.Length-1],ending | None -> w,""
    
breakEndings "xInch" ["Meter";"Inch"]
breakEndings "xInch" ["Metre"]

let endings = ["Meter";"Inch";"KPA"]
type Feature = Fretting|Grinding|Axing
let words = ["RadiusMeter";"RadiusInch";"CenterKPA";"InnerWallKPA";"InnerWallInch"]
words |> Seq.map (fun w -> breakEndings w endings) |> Seq.groupBy fst
words |> Seq.groupBy (fun w -> breakEndings w endings |> fst)

let wordsFe = ["RadiusMeter",[Fretting];"RadiusInch",[Fretting];"CenterKPA",[Grinding;Fretting];"InnerWallKPA",[Grinding;Fretting];"InnerWallInch",[Axing]]
wordsFe |> Seq.groupBy (fun (w,f) -> breakEndings w endings |> fst)

// an hour into this... may make more sense to hand process and check that there was no change