nitrocode

Github "Verified" commits using GPG key with private email

It's nice to see a Verified message next to each commit for peace of mind.

Using GPG or S/MIME, you can sign tags and commits locally. These tags or commits are marked as verified on GitHub so other people can be confident that the changes come from a trusted source.

1. Install latest gpg

   If using a mac use homebrew

chrisdone

Statically checked overloaded strings

This gist demonstrates a trick I came up with which is defining IsString for Q (TExp a), where a is lift-able. This allows you to write $$("...") and have the string parsed at compile-time.

On GHC 9, you are able to write $$"..." instead.

This offers a light-weight way to enforce compile-time constraints. It's basically OverloadedStrings with static checks. The inferred return type

i-am-tom

{-# LANGUAGE BlockArguments   #-}
{-# LANGUAGE DeriveFunctor    #-}
{-# LANGUAGE DeriveGeneric    #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE MonoLocalBinds   #-}
{-# LANGUAGE RecordWildCards  #-}
{-# LANGUAGE TypeApplications #-}
module Main where

import Control.Applicative (Alternative (..))

kamilchm

with import <nixpkgs> {};

let
  jdk = openjdk;
  node = nodejs-10_x;
  sdk = androidenv.androidsdk {
    platformVersions = [ "23" ];
    abiVersions = [ "x86" ];
    useGoogleAPIs = true;
    useExtraSupportLibs = false;

ChristopherKing42

--Roughly based on https://github.com/Gabriel439/Haskell-Morte-Library/blob/master/src/Morte/Core.hs by Gabriel Gonzalez et al.

data Expr = Star | Box | Var Int | Lam Int Expr Expr | Pi Int Expr Expr | App Expr Expr deriving (Show, Eq)

subst v e (Var v')       | v == v' = e
subst v e (Lam v' ta b ) | v == v' = Lam v' (subst v e ta)            b
subst v e (Lam v' ta b )           = Lam v' (subst v e ta) (subst v e b )
subst v e (Pi  v' ta tb) | v == v' = Pi  v' (subst v e ta)            tb
subst v e (Pi  v' ta tb)           = Pi  v' (subst v e ta) (subst v e tb)
subst v e (App f a     )           = App    (subst v e f ) (subst v e a )

flbuddymooreiv

This is the process of setting up erlang, rebar3, and cowboy for a Hello World, starting with a clean Debian 8 install.

Update apt and install deps:

root@046edcaea45a:~# apt-get update
root@046edcaea45a:~# apt-get install erlang erlang-dev gcc
root@046edcaea45a:~# wget https://s3.amazonaws.com/rebar3/rebar3
root@046edcaea45a:~# mkdir ~/bin/
root@046edcaea45a:~# mv rebar3 ~/bin/
root@046edcaea45a:~# chmod +x ~/bin/rebar3 

travisbhartwell

NOTE: a more up-to-date version of this can be found on my blog

nix-shell and Shebang Lines

A few days ago, version 1.9 of the Nix package manager was released. From the release notes:

nix-shell can now be used as a #!-interpreter. This allows you to write scripts that dynamically fetch their own dependencies.

stlehmann

#! python3.4
from setuptools import setup
import os
import py2exe
import matplotlib

includes = ["sip",
            "PyQt5",
            "PyQt5.QtCore",
            "PyQt5.QtGui",

mandiwise

// Reference: http://stackoverflow.com/questions/4822471/count-number-of-lines-in-a-git-repository

$ git ls-files | xargs wc -l

dergachev

name=coursecal-d7
port=$(shell docker inspect -format='{{(index (index .NetworkSettings.Ports "22/tcp") 0).HostPort}}' $(name))


# launches a debug shell into the latest intermediate docker image
debug_latest:
	docker run -t -i `docker images -q | head -n 1` /bin/bash

# DESTROYS all containers (!!) and all images without a tag
# NB: