Функциональное программирование на платформе .Net

open System

let rec rpt n f =
    if n = 0 then id
    else f >> (rpt (n-1) f)

type Complex = 
    { Re : float
      Im : float }

let cm (a:Complex) (b:Complex) =
    { Re = (a.Re * b.Re - a.Im * b.Im); Im = (a.Re*b.Im + a.Im*b.Re)}
let cp (a:Complex) (b:Complex) =
    { Re = (a.Re + b.Re); Im = (a.Im + b.Im)}  

let absComplex (a:Complex) : float = sqrt ( a.Re * a.Re + a.Im * a.Im)
    
let mandelf (c: Complex) (z:Complex) = cp (cm z  z)  c

let isMandel c = absComplex(rpt 20 (mandelf c) ({Re = 0.; Im=0.})) < 1.0
let scale (x:float, y:float) (u,v) n = float(n-u)/float(v-u) * (y-x) + x

for i = 1 to 60 do
    for j = 1 to 60 do
        let lscale = scale (-1.2, 1.2) (1,60) in
        let t = {Re = lscale j; Im = lscale i} in
        Console.Write(if isMandel t then "*" else " ")
    Console.WriteLine("")     

open System.Drawing
open System.Windows.Forms

let form = 
    let image = new Bitmap(400,400)
    let lscale = scale (-1.2, 1.2) (0,image.Height - 1) 
    for i = 0 to image.Height - 1 do
        for j = 1 to image.Width - 1 do
            let t = {Re = lscale j; Im = lscale i}
            image.SetPixel(i,j, if isMandel t then Color.LightGoldenrodYellow else Color.Orange)
    image.Save(@"fs.png")            
    let temp = new Form( Height = image.Height, Width = image.Width)
    temp.Paint.Add (fun e -> e.Graphics.DrawImage(image,0,0))             
    temp

[<STAThread>] do Application.Run(form)