mjrode

The Complete Guide to Nested Forms in Phoenix

I recently spent some time dealing with nested forms in Phoenix. Nested forms are great when you want to create multiple database records in a single transaction and associate them with each other. I am new to Phoenix and really struggled to find any resources that helped me with my specific problem. I decided to document what I learned in the process in hopes of helping others that are new to Elixir and Phoenix.

Here is my attempt at a one stop shop to learn everything you will need to know about nested forms. If you would like to view the GitHub repo you can check it out here.

Thanks to Heartbeat and Jose for excellent blog posts on nested forms. Also shoutout to Josh for showing me some examples at Ruby

garybernhardt

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

jbweston

import random
from itertools import accumulate

# random number generator that will not generate the same sequence
# of pseudorandom numbers if the `random` module is used elsewhere.
# the advantage is a 60x speedup
class Rng:
    def __init__(self, outputs, probabilities, seed=0):
        # test inputs for consistency
        if len(outputs) != len(probabilities):

crushbowl

Looking for a mentor in iOS?- try this post: http://stephaniehurlburt.com/blog/2016/11/14/list-of-engineers-willing-to-mentor-you

General Job Boards

• Angel List - https://angel.co/jobs
• Built In NYC - http://www.builtinnyc.com/jobs
• Women Who Code Job Board - https://www.womenwhocode.com/jobs
• HackerNews Aggregate - http://whereis-whoishiring-hiring.me/
• Indeed.com - https://www.indeed.com
• Core Intuition Jobs (for iOS and Mac Cocoa Developers) - http://jobs.coreint.org/
• Glassdoor Jobs (US/UK) - https://www.glassdoor.com/index.htm

superjamie

Raspberry Pi VPN Router

This is a quick-and-dirty guide to setting up a Raspberry Pi as a "router on a stick" to PrivateInternetAccess VPN.

Requirements

Install Raspbian Jessie (2016-05-27-raspbian-jessie.img) to your Pi's sdcard.

Use the Raspberry Pi Configuration tool or sudo raspi-config to:

eiri

Demonstrate Erlang's 'busy wait' effect on CPU utilization

How?

Just make Erlang to do some light-load task in a bunch of relatively short leaving processes. Calculating PI to 80th digit in batches per 10 procs with short, 8 ms, sleep in-between, to give schedulers a breath space, will do.

Running

Run erl with 8 schedulers and no busy waiting on schedulers at all.

cb372

Category theory jargon cheat sheet

A primer/refresher on the category theory concepts that most commonly crop up in conversations about Scala or FP. (Because it's embarassing when I forget this stuff!)

I'll be assuming Scalaz imports in code samples, and some of the code may be pseudo-Scala.

Functor

A functor is something that supports map.

msgodf

This talk was given by Gregor Kiczales of Xerox PARC at OOPSLA ’94, 10/26/94. © 1994, University Video Communications. A transcript, with point- and-click retrieval of the slides, is available at http:/www.xerox.com/PARC/spl/eca/oi/gregor-invite/gregor- transcript.html

Why are black boxes so hard to reuse?

I think our field will go through a revolution. We will fundamentally change the way we think about and use abstraction in the engineering of software.

The goal of this talk is to summarize the need for and the basic nature of this abstraction framework.

The change is not new problems or new systems, but a new way of thinking about existing problems and existing systems.

r00k

Answer to Question 1

That code violates Tell, Don't Ask..

You could also say it exhibits the feature envy smell.

(Violating Tell, Don't Ask and having feature envy are pretty much two sides of the same coin.)

oakes

Contents

• Why care about Rust?
• The Toolchain
• Creating a New Project
• Modules
• Crates
• Types
• References
• Mutability