regexdna.fs

/// The Computer Language Benchmarks Game
/// http://shootout.alioth.debian.org/
///
/// Modified version of Valentin Kraevskiy
/// Contributed by Vassil Keremidchiev
module Regexdna

open System.Text.RegularExpressions
open System.Threading

let regex s = Regex(s, RegexOptions.Compiled)
let input = stdin.ReadToEnd()
let withoutComments = (regex ">.*\n").Replace(input, "")
let text = (regex "\n").Replace(withoutComments, "")

let rec onblocks res s = 
  let size = 1024 * 4096
  match s with
  | "" -> res
  | s when (s.Length < size) -> res @ [ s ]
  | s -> onblocks (res @ [ s.Substring(0, size) ]) (s.Substring(size))

[ "agggtaaa|tttaccct"; "[cgt]gggtaaa|tttaccc[acg]"; "a[act]ggtaaa|tttacc[agt]t"; 
  "ag[act]gtaaa|tttac[agt]ct"; "agg[act]taaa|ttta[agt]cct"; 
  "aggg[acg]aaa|ttt[cgt]ccct"; "agggt[cgt]aa|tt[acg]accct"; 
  "agggta[cgt]a|t[acg]taccct"; "agggtaa[cgt]|[acg]ttaccct" ]
|> List.map 
     (fun s -> 
     async 
       { 
       return System.String.Format("{0} {1}", s, ((regex s).Matches text).Count) })
|> Async.Parallel
|> Async.RunSynchronously
|> Array.iter (printfn "%s")

let newTextLength t = 
  [ "B", "(c|g|t)"
    "D", "(a|g|t)"
    "H", "(a|c|t)"
    "K", "(g|t)"
    "M", "(a|c)"
    "N", "(a|c|g|t)"
    "R", "(a|g)"
    "S", "(c|g)"
    "V", "(a|c|g)"
    "W", "(a|t)"
    "Y", "(c|t)" ]
  |> List.fold (fun s (code, alt) -> (regex code).Replace(s, alt)) t
  |> String.length

let newText = 
  text
  |> onblocks []
  |> Seq.map (fun s -> async { return newTextLength s })
  |> Async.Parallel
  |> Async.RunSynchronously
  |> Array.sum

printf "\n%i\n%i\n%i\n" input.Length text.Length newText