aaronlevin

/**
 * Let's write a typeclass for a coproduct. The idea is we're given the name of a string, and we need to:
 * 
 * 1. check that the string matches a value
 * 2. if the string matches a value, convert that string into some type and return it
 * 3. If the string doesn't match that value, try another alternative.
 * 4. If no alternatives match the value, return an error.
 * 
 * The usecase is based on something I encountered in real life: we have to parse different kind of events in
 * my work's data pipeline, and the type of event (and subsequent parsing) depends on an "event type" string. I

aaronlevin

/**
* Working with shapeless' records is great. However, you are limited to using only String, Integer, Boolean, and
* (package) Objects as singleton keys as the singleton machinery requires a stable point (I don't really fully
* understand this part but I have an intuition). I had asked if there was a way to use a tuple or case-class 
* as a key in the shapeless gitter channel and no one really knew.
* 
* I was reading the shapeless source for the Witness type and an idea came to mind: since we can use a package Object 
* as a key, what if that key extends a trait (an abstract class can work as well)? Can we use those objects as 
* singleton keys and access the values specified in the trait?
* 

aaronlevin

# I wanted to use ensime with vim, which requires vim + python + some python packages (websocket_client + sexpdata)
# unfortunately, nix would build vim with a python that didn't have access to my system libraries (for referential transperancy)
# so I needed to provide to `vim_configurable.nix` the right python to use *and* enable python, lua, etc. support.
# I also wanted to keep my `.vimrc` separate because some of the vim packages I use weren't available.
#
# install via: `nix-env -f '<nixpkgs>' -iA myCoolVim` or `nix-env -I nixpkgs=/path/to/your/nixpkgs -f '<nixpkgs>' -iA myCoolVim`
#
# out put of `vim --version` below.

{

aaronlevin

# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).

{ config, pkgs, ... }:

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix

aaronlevin

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleInstances     #-}
{-# LANGUAGE FlexibleContexts     #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeOperators #-}

module HList where

aaronlevin

{-# LANGUAGE DataKinds              #-}
{-# LANGUAGE FlexibleContexts       #-}
{-# LANGUAGE FlexibleInstances      #-}
{-# LANGUAGE GADTs                  #-}
{-# LANGUAGE KindSignatures         #-}
{-# LANGUAGE MultiParamTypeClasses  #-}
{-# LANGUAGE PolyKinds              #-}
{-# LANGUAGE RankNTypes             #-}
{-# LANGUAGE TypeOperators          #-}

aaronlevin

{-# LANGUAGE DataKinds              #-}
{-# LANGUAGE FlexibleContexts       #-}
{-# LANGUAGE FlexibleInstances      #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE GADTs                  #-}
{-# LANGUAGE KindSignatures         #-}
{-# LANGUAGE MultiParamTypeClasses  #-}
{-# LANGUAGE PolyKinds              #-}
{-# LANGUAGE RankNTypes             #-}
{-# LANGUAGE ScopedTypeVariables    #-}

aaronlevin

#!/usr/bin/env bash

# modified from: http://tmont.com/blargh/2014/1/uploading-to-s3-in-bash

readonly db_host="xxxx"
readonly db_user="xxxx"
readonly db_pass='xxxx'
readonly db_db="xxx"
readonly aws_key="xxxx"
readonly aws_secret="xxxxx"

aaronlevin

Keybase proof

I hereby claim:

• I am aaronlevin on github.
• I am aaronlevin (https://keybase.io/aaronlevin) on keybase.
• I have a public key whose fingerprint is 5589 E5EA F9E3 5955 A53D 0714 3ADD FECC C5D5 CD5E

To claim this, I am signing this object:

aaronlevin

Keybase proof

I hereby claim:

• I am aaronlevin on github.
• I am aaronlevin (https://keybase.io/aaronlevin) on keybase.
• I have a public key whose fingerprint is 3900 0396 924C 9990 4912 94D3 FDD0 B4E9 9845 2EE5

To claim this, I am signing this object: