functional programming - Further optimizing Number to Roman Numeral function in F# -


i'm new f# , i'm curious if can still optimized further. not particularly sure if i've done correctly well. i'm curious particularly on last line looks long , hideous.

i've searched on google, roman numeral number solutions show up, i'm having hard time comparing.

type romandigit = | iv | v | ix let rec romannumeral number =     let values = [ 9; 5; 4; 1 ]     let capture number values =             values             |> seq.find ( fun x -> number >= x )     let toromandigit x =         match x         | 9 -> ix         | 5 -> v         | 4 -> iv         | 1 ->     match number     | 0 -> []     | int -> seq.tolist ( seq.concat [ [ toromandigit ( capture number values ) ]; romannumeral ( number - ( capture number values ) ) ] )

thanks can problem.

a shorter way of recursively finding largest digit representation can subtracted value (using list.find):

let units =     [1000, "m"      900, "cm"      500, "d"      400, "cd"      100, "c"      90, "xc"      50, "l"      40, "xl"      10, "x"      9, "ix"      5, "v"      4, "iv"      1, "i"]  let rec toromannumeral = function     | 0 -> ""     | n ->         let x, s = units |> list.find (fun (x,s) -> x <= n)         s + toromannumeral (n-x)

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