This is a work in progress where I try to convey what high quality software means to me, and how to build it. Be warned: This is a very opinionated and handwavy guide.
Copyright Renzo Carbonara, 2016. This work is licensed under a Creative Commons Attribution 4.0 International License.
| let | |
| hpack2nix = | |
| name: src: | |
| let | |
| addCabalFile = stdenv.mkDerivation { | |
| inherit name src; | |
| phases = [ "unpackPhase" "patchPhase" "installPhase" ]; | |
| installPhase = ''cp -r . $out''; | |
| patchPhase = '' | |
| ${haskellPackages.hpack}/bin/hpack |
| module Printf | |
| %default total | |
| -- Formatting AST. | |
| data Format | |
| = FInt Format | |
| | FString Format | |
| | FOther Char Format | |
| | FEnd |
Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.
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
| package main | |
| import ( | |
| "fmt" | |
| "reflect" | |
| ) | |
| // Name of the struct tag used in examples | |
| const tagName = "validate" |
| import ( | |
| "mime" | |
| "net/http" | |
| "strings" | |
| ) | |
| // Determine whether the request `content-type` includes a | |
| // server-acceptable mime-type | |
| // | |
| // Failure should yield an HTTP 415 (`http.StatusUnsupportedMediaType`) |
| sealed trait RegExp { | |
| def isFinal:Boolean | |
| def acceptsEmpty:Boolean | |
| def shift(prev:Boolean, character:Char):RegExp | |
| def matches(str:String) = | |
| if(str.isEmpty) this.acceptsEmpty | |
| else str.foldLeft(this.shift(true, str.head))(_.shift(false,_)).isFinal | |
| } | |
| object Epsilon extends RegExp { |
| # <type>: (If applied, this commit will...) <subject> (Max 50 char) | |
| # |<---- Using a Maximum Of 50 Characters ---->| | |
| # Explain why this change is being made | |
| # |<---- Try To Limit Each Line to a Maximum Of 72 Characters ---->| | |
| # Provide links or keys to any relevant tickets, articles or other resources | |
| # Example: Github issue #23 |
Every application ever written can be viewed as some sort of transformation on data. Data can come from different sources, such as a network or a file or user input or the Large Hadron Collider. It can come from many sources all at once to be merged and aggregated in interesting ways, and it can be produced into many different output sinks, such as a network or files or graphical user interfaces. You might produce your output all at once, as a big data dump at the end of the world (right before your program shuts down), or you might produce it more incrementally. Every application fits into this model.
The scalaz-stream project is an attempt to make it easy to construct, test and scale programs that fit within this model (which is to say, everything). It does this by providing an abstraction around a "stream" of data, which is really just this notion of some number of data being sequentially pulled out of some unspecified data source. On top of this abstraction, sca
| {-# LANGUAGE NoMonomorphismRestriction #-} | |
| {-# LANGUAGE TemplateHaskell #-} | |
| {-# OPTIONS_GHC -fwarn-missing-methods #-} | |
| module Err where | |
| import Control.Lens | |
| import Control.Monad.Error | |
| import Control.Monad.Error.Lens | |
| -- Here is a fairly typical situation, where we have low level errors in certain |
