fsharp-learning/exercism/fsharp/kindergarten-garden/KindergartenGarden.fs

module KindergartenGarden

open System

type Plant =
    | Grass
    | Clover
    | Radishes
    | Violets

let getNumFromName (student: string) = int (student.[0]) - int ('A')

let getPlantChars (row: string) num =
    [ for c in (row.[(num * 2)..(num * 2 + 1)]) -> c ]

let plants (diagram: string) (student: string) =
    diagram.Split [| '\n' |] // Split the rows up
    |> Seq.map (fun i -> (getPlantChars i (getNumFromName student))) // Go over each row getting the child's plants
    |> Seq.reduce List.append // This flattens the list becuase before this it looks like [['a', 'b']['c', 'd']] and we want ['a', 'b', 'c', 'd']
    |> List.map (fun i -> // Now for each plant character return the relavant plant type
        match i with
        | 'G' -> Grass
        | 'C' -> Clover
        | 'R' -> Radishes
        | _ -> Violets)