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@chriseidhof
chriseidhof / TypedExpr.swift
Last active February 3, 2018 23:01
Typed Expressions in Swift
// Variables just contain an integer. We can have a maximum of `Int.max` variables in our program. ¯\_(ツ)_/¯
private struct Var {
static var freshVarIx = 0
let ix: Int
init() {
Var.freshVarIx+=1
ix = Var.freshVarIx
}
}
@harlow
harlow / golang_job_queue.md
Last active April 24, 2024 10:21
Job queues in Golang

Swift Don'ts

  • Don't add code cruft. Avoid parentheses around conditions in if-statements or with the return keyword. Don't add semicolons except where syntactically demanded in statements or to separate statements on the same line.
  • Don't use ALL_CAPS; use camelCase
  • Don't fight type inference. Use enumeration prefixes, self-references, and class names (with constructors) only when necessary or to clarify coding intent.
  • Don't use var when let is appropriate, especially for properties. The compiler better optimizes let statements for items whose values will not change during their lifetime. For example, Apple writes, "It is good practice to create immutable collections in all cases where the collection does not need to change. Doing so enables the Swift compiler to optimize the performance of the collections you create."
  • Don't use classes when structs will do. Use class

There are three easy to make mistakes in go. I present them here in the way they are often found in the wild, not in the way that is easiest to understand.

All three of these mistakes have been made in Kubernetes code, getting past code review at least once each that I know of.

  1. Loop variables are scoped outside the loop.

What do these lines do? Make predictions and then scroll down.

func print(pi *int) { fmt.Println(*pi) }
@staltz
staltz / introrx.md
Last active May 24, 2024 07:56
The introduction to Reactive Programming you've been missing
@JaviSoto
JaviSoto / ReactiveCocoa.md
Last active August 29, 2015 13:56
ReactiveCocoa

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. Some 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 new-commers, 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

@mattt
mattt / NSRange-Conventional.h
Last active January 22, 2020 23:32
Re-declaration of existing `NSRange` functions and implementation of new functions to match conventions of comparable Foundation and Core Foundation types.
NS_INLINE NSRange NSRangeMake(NSUInteger loc, NSUInteger len) {
return NSMakeRange(loc, len);
}
NS_INLINE NSUInteger NSRangeMax(NSRange range) {
return NSMaxRange(range);
}
NS_INLINE BOOL NSRangeContainsLocation(NSUInteger loc, NSRange range) {
return NSLocationInRange(loc, range);
@floriankugler
floriankugler / gist:6870499
Last active September 29, 2023 15:56
Mapping of NSURLConnection to NSURLSession delegate methods. Created by Mattt Thompson.
NSURLConnection | NSURLSession
------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------
NSURLConnectionDelegate connectionShouldUseCredentialStorage: |
------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------
NSURLConnectionDelegate connection:willSendRequestForAuthenticationChallenge: | NSURLSessionDelegate URLSession:didReceiveChallenge:completionHandler:
| N
@mattt
mattt / UIImageForSwatchOfColorWithSize.h
Created September 27, 2013 01:25
Create a UIImage swatch of a color with a specified size.
static UIImage * UIImageForSwatchOfColorWithSize(UIColor *color, CGSize size) {
UIImage *image = nil;
CGRect rect = CGRectMake(0.0f, 0.0f, size.width, size.height);
UIGraphicsBeginImageContext(rect.size);
{
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(c, [color CGColor]);
@AnuragMishra
AnuragMishra / DateParsingPerformanceComparison.m
Last active July 29, 2020 17:20
Compare the date parsing performance of NSDateFormatter against SQLite's date parser for parsing an iOS 8601 date.
#import <Foundation/Foundation.h>
#import "sqlite3.h"
typedef int64_t timestamp;
NSUInteger randomNumberInRange(NSUInteger start, NSUInteger end);
// Create a sample date using the ISO-8601 format.
// 2013-04-23T16:29:05Z
NSString* generateSampleDate();