sevanspowell

Running Emacs Haskell Tooling in a Nix environment

A guide to setting up the Haskell tooling for Emacs in a Nix environment.

Suggestions/Contact

mail@sevanspowell.net

Configuration

geowarin

package completable.async;


import java.util.Collection;
import java.util.List;
import java.util.concurrent.*;

import static java.util.concurrent.Executors.callable;

/**

runarorama

trait λ {
  type α
}

trait Functor extends λ {
  type α <: λ

  def map[A,B](x: α { type α = A })(f: A => B): α { type α = B }
}

timjb

import Test.QuickCheck
import Control.Applicative ((<$>))
import Data.List (scanl)

-- To test whether my timsort implementation has the bug described in
-- http://envisage-project.eu/proving-android-java-and-python-sorting-algorithm-is-broken-and-how-to-fix-it/
-- Answer: yes :-(

runLengthInvariantBroken :: (Num i, Ord i) => i -> i -> i -> i -> Bool
runLengthInvariantBroken a b c i = (b - a <= i - b) || (c - b <= i - c)

mbrcknl

Require Import List.
Import ListNotations.

Set Implicit Arguments.

Fixpoint reverse (X: Type) (xs: list X): list X :=
  match xs with
    | [] => []
    | x :: xs' => reverse xs' ++ [x]
  end.

AlexCharlton

;;;; This script can be loaded during emacs initialization to automatically
;;;; send `kill-region' and `kill-ring-save' regions to your system clipboard.
;;;; The OSC 52 terminal escape sequence is used to transfer the selection from
;;;; emacs to the host terminal.

;;;; It is based off of the osc52.el copyright the Chromium OS authors, but
;;;; was modified to add support for tmux, graphical displays, and
;;;; multi-byte strings.

;;;; It works in hterm, xterm, and other terminal emulators which support the

markhibberd

So what I understand to be your questions:

1. What is a coherency problem?
2. What does over constained code look like / cause?
3. How do you lose your "desired" instance?

A way to step through understanding this problem:

• Oh shit, If I have local type classes, I have to handle crazy wacky cases in my implementation, this will likely have performance and correctness implications (see Coherency.scala)
• What happens if I close over constraint on construction? Oops if I close over it, I end up with OverConstrained code (see OverConstrainedCode.scala) and worse I still have coherency issues, and the ability to lose my intended behavious (LosingAnInstance.scala)
• Oh wow, if I just don't do local type classes, by never define conflicting implicits, and ascribe a single type to each behaviour, everything is simple and just works.

softprops

• hprof a builtin java agent which dumps profiling info at runtime
• class sharing class file cache used for faster startup times
• pack200 unpack200 uber packed jars
• mission control a Profiling, Monitoring, and Diagnostics Tools Suite
• jstat performance stats tool
• jhat heap dump browser
• jmap memory maps
• jstack prints stack trace of running process

msmuenchen

Convention: Byte array notation as it would appear in a hexeditor.

= Layout=

KDBX files, the keepass database files, are layout as follows:

1) Bytes 0-3: Primary identifier, common across all kdbx versions: 
  private static $sigByte1=[0x03,0xD9,0xA2,0x9A];

2) Bytes 4-7: Secondary identifier. Byte 4 can be used to identify the file version (0x67 is latest, 0x66 is the KeePass 2 pre-release format and 0x55 is KeePass 1)

master-q

### Versions
casper$ patsopt --version
Hello from ATS2(ATS/Postiats)!
ATS/Postiats version 0.0.6 with Copyright (c) 2011-2014 Hongwei Xi
casper$ ajhc --version
ajhc 0.8.0.11 (e601dfc26abce79686e41c2609ed5beb7fd7f4d5)
compiled by ghc-7.6 on a x86_64 running linux
casper$ idris --version
Idris version 0.9.11.2