barambani

So we have all these types like Int, Float, String, Map String Int, [Maybe String], etc. What do all these types have in common? Well, essentially, they're "normal" types where we can make a value for them. Just as values have types, types have "kinds". In this case, just as 4 : Int, Int : *, and just as "Hello" : String, String : *. That is to say, all these normal types (the types of plain old values) have kind *.

Now, in OCaml, you have type parametricity, but only over types of kind *. Let's give an example of a type that's not of kind *.

Map : * -> * -> *

We apply this "type constructor" (which is a kind of "type function", just like constructors are a kind of function) to the type Int : *.

Map Int : * -> *

barambani

object Functions {

  /**
    * Functions
    * - Total (every element in the domain must have a representation in the co-domain)
    * - Deterministic (give always the same result for the same input)
    * - Not side effecting (the only result of the function is the mapped value)
    */

  /**

barambani

Advanced Functional Programming with Scala - Notes

Copyright © 2016-2017 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

barambani

" Initialize plugin system
call plug#begin('~/.vim/plugged')

Plug 'rizzatti/dash.vim'
Plug 'derekwyatt/vim-scala'
Plug 'vim-syntastic/syntastic'
Plug 'kien/ctrlp.vim'
Plug 'scrooloose/nerdtree'
Plug 'Xuyuanp/nerdtree-git-plugin'
Plug 'ervandew/supertab'