henrytill

#! /usr/bin/env bash

channels=${1:-nixos-15.09-small nixos-15.09 nixos-unstable-small nixos-unstable nixpkgs-unstable}
site=${2:-https://nixos.org/channels}

getChannelVersion () {
    basename $(curl -ILs -w %{url_effective} -o /dev/null $1) | cut -d - -f 2
}

for name in ${channels[@]}

henrytill

;   Copyright (c) Rich Hickey. All rights reserved.
;   The use and distribution terms for this software are covered by the
;   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
;   which can be found in the file epl-v10.html at the root of this distribution.
;   By using this software in any fashion, you are agreeing to be bound by
;   the terms of this license.
;   You must not remove this notice, or any other, from this software.

(set! *warn-on-reflection* true)

henrytill

module type Functor = sig
  type 'a t
  val map : ('a -> 'b) -> ('a t -> 'b t)
end

module Iso = struct
  type ('a, 'b) t = { fwd : 'a -> 'b; bck : 'b -> 'a }

  let fwd i = i.fwd
  let bck i = i.bck

henrytill

module type Functor = sig
  type 'a t
  val map : ('a -> 'b) -> ('a t -> 'b t)
end

module Mu (F : Functor) : sig
  type t = { mu : t F.t }
  val cata : ('a F.t -> 'a) -> (t -> 'a)
end = struct

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(* an abstract signature for instantiations of the existential quantifier *)
module type EXISTS =
sig
  (* the predicate *)
  type 'a phi

  (* the existential type *)
  type t

  (* the introduction rule *)

henrytill

signature EQ =
sig
  type t
  val eq : t * t -> bool
end

signature SHOW =
sig
  type t
  val toString : t -> string

henrytill

(** "Landin's Knot" - implements recursion by backpatching *)
let landins_knot f =
  let r = ref (fun x -> assert false) in
  let fixedpoint = f (fun x -> !r x) in
  r := fixedpoint;
  fixedpoint

let factorial =
  let g f x =
    if x = 0 then

henrytill

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

henrytill

AlignAfterOpenBracket: DontAlign
AlignConsecutiveMacros: true
AlignOperands: DontAlign
AlignTrailingComments: true
AllowAllArgumentsOnNextLine: true
AllowAllParametersOfDeclarationOnNextLine: false
AllowShortBlocksOnASingleLine: Empty
AllowShortCaseLabelsOnASingleLine: true
AllowShortEnumsOnASingleLine: true
AllowShortFunctionsOnASingleLine: true

henrytill

How I removed guix

(loose ref: https://www.mail-archive.com/help-guix@gnu.org/msg10948.html)

sudo systemctl disable guix-daemon.service
sudo systemctl disable gnu-store.mount
systemctl reboot
sudo rm -rf /gnu
sudo rm -rf /var/guix