aoc-2017-day3-part2-generate-ring.fs

let generateRing ringId previousRing =
    let rowLength = ringId * 2
    let ringSize = rowLength * 4
    let ring = Array.zeroCreate ringSize
    let data = (rowLength, previousRing, ring)

    for i in 0 .. (ringSize - 1) do
        let value = 
            match (data, i) with
            | FirstItem v      
            | LastItem v       
            | BeforeLastItem v 
            | BeforeCorner v   
            | Corner v         
            | AfterCorner v    -> v
            | x                -> calculateMiddle x
        ring.[i] <- value
    ring