timarnold

ReactiveCocoa

A lot is being written these days about ReactiveCocoa and the paradigms it introduces. In my opinion, there are only two sides giving their opinion: the ones that know a lot about it and are therefore obviously biased, and the ones that refuse to learn it.

I decided to write something myself because I think I'm right in the middle. A few months ago I knew nothing about it, and now I know enough to want to use it every day. I hope that by not being an expert, I can actual introduce a few really simple ideas in a much easier way to pick up by newcomers, to show why I think ReactiveCocoa is an incredibly powerful tool to help us write better, cleaner, and more maintainable code.

It's signals all the way down

The base of everything that happens in ReactiveCocoa is signals. I'm going to try to explain what they represent and why they fit in the way we think about what happens on an app. A lot of the things you may read about Functional Reactive Programming end up confusing you when t

timarnold

require 'rubygems'
require 'json'
require 'cgi'
require "net/http"
require "uri"

# Find your store here: http://www.ifoapplestore.com/store-number-list/
stores = 
    { 
    "Towson"   => "R063",

timarnold

tell application "Safari"
    make new document at end of documents
    set url of document 1 to "http://www.google.com/search?q=list of episodes wiki %fill:Show Name%&btnI=Im+Feeling+Lucky"
end tell
return " "

timarnold

tell application "Safari"
    make new document at end of documents
    set url of document 1 to "http://duckduckgo.com/?q=\\list+of+episodes+wiki+%fill:Show Name%"
end tell
return " "

timarnold

CADisplayLink *link = [CADisplayLink displayLinkWithTarget:self selector:@selector(update:)];
link.frameInterval = 60; // every 60 frames = 1 second send the update: message
link.paused = NO; // default is NO
[link addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];

- (void)update:(CADisplayLink *)displayLink {
  // Do all the things!
}

timarnold

Game with Javier Soto Bustos
played with Tall Chess

1. d4 d5
2. c4 e6
3. ♘f3 ♞c6
4. ♘c3 ♝b4
5. ♕c2 ♞f6
6. a3 ♝xc3+
7. bxc3 0–0

timarnold

    UIImage *im = [UIImage imageNamed:@"8n2ty.jpg"];
    UIImageView *iv = [[UIImageView alloc] initWithImage:im];
    [self.view addSubview:iv];

    CGFloat w = im.size.width / 2.;
    CGFloat h = im.size.height / 2.;
    UIImage *q1, *q2, *q3, *q4;
    CGRect r1 = CGRectMake(0, 0, w, h);
    CGRect r2 = CGRectMake(w, 0, w, h);
    CGRect r3 = CGRectMake(0, h, w, h);

timarnold

Keybase proof

I hereby claim:

• I am timcamber on github.
• I am timcamber (https://keybase.io/timcamber) on keybase.
• I have a public key whose fingerprint is CFB3 7C3F 33A3 9FEF 176D 9842 5293 C403 EEE0 C3C8

To claim this, I am signing this object:

timarnold

#!/usr/bin/env python

import math
import rospy
from std_msgs.msg import Float64
from sensor_msgs.msg import JointState
from simple_arm.srv import *

def at_goal(pos_j1, goal_j1, pos_j2, goal_j2):
    tolerance = .05

timarnold

#!/usr/bin/env python

import math
import rospy
from sensor_msgs.msg import Image, JointState
from simple_arm.srv import *


class LookAway(object):
    def __init__(self):