dgfitch

open System.IO

type Walker(p) =
  let root = new DirectoryInfo(p)
  let root_path = root.FullName

  let link (f:FileInfo) =
    let relative_path = f.FullName.Replace(root_path, "").TrimStart('\\')
    printfn "<p><a href='%s'>%s</a></p>" relative_path f.Name

dgfitch

(* First, a few dumb extensions on IEnumerable *)

type System.Collections.Generic.IEnumerable<'a> with
  member xs.ChopHead = (Seq.head xs, Seq.skip 1 xs)
  member xs.Cut f = (Seq.takeWhile f xs, Seq.skipWhile f xs)


(* Given a sequence, I want to partition it according to some fairly complex rules.
   I'm using a pair of sequence expressions depending on what's at the head of the sequence.
   Unfortunately, this code is prohibitively slow for the large inputs I'm sending it.

dgfitch

  let FReplace (remove:string) (replace:string) (input:string) = input.Replace(remove, replace)

  let Insert sql s1 s2 =
    sql
    |> FReplace "step1" s1
    |> FReplace "step2" s2

  (* OR, possibly more concise: *) 

  let PipeInsert s1 s2 =

dgfitch

let awesome (x:string) =
  if x.Contains "awesome" then
    5
  else
    0

(* everything is fine so far... *)


let mutable guyFuckedUp = false

dgfitch

(* In this weird case I need to write a stream but also keep track of how long ago a linefeed was written *)

    member s.WriteStream (from:Stream) =
      use reader = new StreamReader(from)
      let mutable buffer = Array.zeroCreate<char>(BUFFER_LENGTH)
      let mutable len = 0
      while not reader.EndOfStream do
        len <- reader.ReadBlock(buffer, 0, buffer.Length)
        s.OutputWriter.Write(buffer, 0, len) 
        (* Now, walk backwards through the buffer looking for linefeeds *)

dgfitch

let set = Set.ofList
let map = Map.ofList

let w = set [1; 2; 2; 5]
let x = map [("foo", 1); ("bar", 2)]

let (~~) = set
let (!!) = map

let y = ~~ [1; 2; 2; 5]

dgfitch

xUnit.net console test runner (32-bit .NET 4.0.30319.1)
Copyright (C) 2007-9 Microsoft Corporation.

xunit.dll:     Version 1.5.0.1479
Test assembly: e:\svn\dtc\Tests\UnitTests\bin\Local\UnitTests.dll

..................................................................................................................................................................FFFFFFF......F..FF.FFF.F...................................................................................................................................................................................................................................
Total tests: 413, Failures: 14, Skipped: 0, Time: 5.457 seconds

dgfitch

let f x = sprintf "[%A]" x
let g x = sprintf "{%A}" x

(*  So you have two functions (string -> string)
    Now, you want to do let result = f g "hi"
    However, f doesn't take a function string -> string, it takes a string. 
    So you need to tell the compiler about your precedence.

    Normal "idiomatic" ways: *)

dgfitch

(*

A parser needs to compress input as it receives it,
but it may receive the characters in small chunks.
How does the .NET System.IO.Compression namespace
deal with small chunks? Let's see the worst case!

*)

let streamToString (x:MemoryStream) =

dgfitch

let x_X = (+) "ouch"
let (---) x y = x + " don't" + y
let (!^-^) x = " punch" + x
let Q = " face"
let O = " please"

let emoticon = (x_X) O---(!^-^Q)