expede

;; -*- mode: emacs-lisp -*-
;; This file is loaded by Spacemacs at startup.
;; It must be stored in your home directory.

(defun dotspacemacs/layers ()
  "Configuration Layers declaration.
You should not put any user code in this function besides modifying the variable
values."
  (setq-default
   ;; Base distribution to use. This is a layer contained in the directory

expede

  query IntrospectionQuery {
    __schema {
      queryType { name }
      mutationType { name }
      types {
        ...FullType
      }
      directives {
        name
        description

expede

# ========
# NOTATION
# ========

# Control.Monad (Haskell) Bind
>>=

# Witchcraft.Chain.bind (Elixir)
>>>

expede

Interactive Elixir (1.6.4) - press Ctrl+C to exit (type h() ENTER for help)

iex(1)> use Witchcraft
iex(2)> alias Algae.Maybe

# With a Just
iex(5)> monad %Maybe.Just{} do  
...(5)>   a <- Maybe.Just.new(1)
...(5)>   b <- Maybe.Just.new(2)
...(5)>   return(a + b)         

expede

-- Just the code from http://programmers.stackexchange.com/a/242803
-- ...I find it useful to type this stuff out. Weird, I know.

data DSL next = Get String (String -> next)
              | Set String String next
              | End

p1 :: DSL (DSL (DSL next))
p1 = Get "foo" $ \foo -> Set "bar" foo End

expede

x == x -- Reflixivity 

x * 0     == 0 -- Origin
x * 0 * 0 == 0 -- Idempotence

x + 0 == x -- Additive identity
x / 1 == x -- Divisive identity
x * 1 == x -- Multiplicative identity

expede

{-
  Vectors are fixed-length data structures
  They're written in this format: `Vect length type`
  
  ex. `Vect 3 Int` could represent [1,2,3], but not [1,2] or ['a', 'b', 'c']
-} 

concat : Vect lengthX a -> Vect lengthY a -> Vect (lengthX + lengthY) a
concat Nil       ys = ys
concat (x :: xs) ys = x :: app xs ys

expede

return a >>= f  == f a -- Left Identity
m >>= return    == m   -- Right Identity
(m >>= f) >>= g == m >>= (\x -> f x >>= g) -- Associativity
-- ...plus all applicative functor laws

expede

# Hypothetical rewrite of `File.read`
# Not the lack of a `OtherFile.read!` (with a bang),
# but we get the same effect with the caller via `>>>`

# Success
iex> OtherFile.read("./existing_file.txt")
"I'm a little teapot short and stout ..."

# Error
# Note that this returns an Exception struct as a value

expede

use Exceptional

# Success case
iex> OtherFile.read("./existing_file.txt") >>> String.length
1000

# Error case                           
iex> OtherFile.read("./missing.file") >>> String.length
**(OtherFile.NotFoundError) File not found at ./missing.file