| // when T is any|unknown, Y is returned, otherwise N | |
| type IsAnyUnknown<T, Y, N> = unknown extends T ? Y : N; | |
| // when T is never, Y is returned, otherwise N | |
| type IsNever<T, Y = true, N = false> = [T] extends [never] ? Y : N; | |
| // when T is a tuple, Y is returned, otherwise N | |
| // valid tuples = [string], [string, boolean], | |
| // invalid tuples = [], string[], (string | number)[] |
| const daggy = require('daggy'); | |
| const {foldMap} = require('pointfree-fantasy') | |
| const {concat, toUpper, prop, identity, range, compose} = require('ramda'); | |
| // Contravariant functors usually have this shape F(a -> ConcreteType). | |
| // In other words, some type holding a function which is parametric on its input, but not output. | |
| // They don't always have that shape, but it's a good intuition | |
| // Covariant functors are what we're used to, which are parametric in their output | |
| //================================================================ |
| alias pgstart="pg_ctl -D /usr/local/var/postgres -l /usr/local/var/log/postgres/server.log start" | |
| alias pgstop="pg_ctl -D /usr/local/var/postgres stop -m fast" | |
| # find id of last backup | |
| __getBackupId() { | |
| echo $( heroku pg:backups | grep 'b\d\d\d' | head -1 | cut -b 1-6 | xargs ) | |
| } | |
| # get the app's name from heroku info | |
| __getAppName() { |
Following is a translation of a post by Kenta Cho (@abagames) about what he learned making 50 minigames in 2014. The original post is here:
http://d.hatena.ne.jp/ABA/20141223#p1
This translation is by Paul McCann (@polm23); please feel free to contact me with any comments or corrections.
... is that there isn't one.
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
This post also appears on lisper.in.
Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.
Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):
The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.
| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta charset="utf-8" /> | |
| <meta http-equiv="content-type" content="text/html; charset=utf-8" /> | |
| <title>sorting lists</title> | |
| <script src="jquery-1.7.2.min.js"></script> | |
| <script src="jquery.sortChildren.js"></script> | |
| <script> |
I'm a fan of MiniTest::Spec. It strikes a nice balance between the simplicity of TestUnit and the readable syntax of RSpec. When I first switched from RSpec to MiniTest::Spec, one thing I was worried I would miss was the ability to add matchers. (A note in terminology: "matchers" in MiniTest::Spec refer to something completely different than "matchers" in RSpec. I won't get into it, but from now on, let's use the proper term: "expectations").
Let's take a look in the code (I'm specifically referring to the gem, not the standard library that's built into Ruby 1.9):
# minitest/spec.rb
module MiniTest::Expectations
| class PostsController < ActionController::Base | |
| def create | |
| Post.create(post_params) | |
| end | |
| def update | |
| Post.find(params[:id]).update_attributes!(post_params) | |
| end | |
| private |