Catfish-Man

// Compile with clang -framework Foundation sethack.m

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

/*
 CFHashBytes from http://www.opensource.apple.com/source/CF/CF-1153.18/CFUtilities.c
 */
#define ELF_STEP(B) T1 = (H << 4) + B; T2 = T1 & 0xF0000000; if (T2) T1 ^= (T2 >> 24); T1 &= (~T2); H = T1;

zwaldowski

public final class StaticCStringArray {

    private let storage: AnyForwardCollection<StaticString>
    private lazy var pointers: ContiguousArray<UnsafeMutablePointer<Int8>> = {
        ContiguousArray(self.storage.lazy.map { UnsafeMutablePointer($0.utf8Start) })
    }()

    init<Collection: CollectionType where Collection.Generator.Element == StaticString>(_ strings: Collection) {
        self.storage = AnyForwardCollection(strings)

shepting

//
//  main.swift
//  NodeTraversal
//
//  Created by Steven Hepting on 11/16/15.
//  Copyright © 2015 Steven Hepting. All rights reserved.
//  Algorithm from http://bit.ly/1kSdSvc
//

import Foundation

twostraws

//
//  SimpleScrollingStack.swift
//  A super-simple demo of a scrolling UIStackView in iOS 9
//
//  Created by Paul Hudson on 10/06/2015.
//  Learn Swift at www.hackingwithswift.com
//  @twostraws
//

import UIKit

JadenGeller

/*
 * We've defined "traits" by which we can type an integer that are characteristic of its value.
 * These traits can even be subtraits of other traits (like both positive and negative being nonzero).
 *
 * We can use these traits in the type signatures of functions to indicate what trait will be returned
 * as a function of the passed-in traits. 
 *
 * Even cooler, we can specify properties of the traits such that we can runtime-verify the correctness
 * of these labels (in case a function was improperly annotated, for example).
 */

gist:8a163db3f7f3d81d5296

Your goals are to reduce the number of things that you have to keep in your head at any given moment, and to rely as little as possible on your own ability to consistently do things right.
If you make a thing immutable ('let' in swift), you never have to think about what happens if it changes, or what other parts of the code you'll effect if you change it.
If you split complex functions into several smaller functions that only interact by passing arguments or getting return values, then you limit the amount of code you need to consider when hunting for a bug, and you can test each small piece separately.
If you understand what things must be true in your code (aka invariants, for example "a person's age must be greater than 0"), and either provide no function that can cause them to be untrue, or check and crash immediately when they're untrue, then you don't have to debug issues caused by incorrect assumptions.
If you remove possibilities (for example, Swift removes the possibility of things being nil unless 

zwaldowski

import Foundation

// MARK: String

extension String {
    
    func convert(#index: Int) -> Index? {
        let utfIndex = advance(utf16.startIndex, index, utf16.endIndex)
        return utfIndex.samePositionIn(self)
    }

odeke-em

#!/bin/bash
target_name="foo" # Remember to set your name here
target_email="foo@example.com" # Set the new email here
git filter-branch --commit-filter 'if [ "$GIT_AUTHOR_NAME" = $target_name ];
  then export GIT_AUTHOR_EMAIL=$target_email;
  fi; git commit-tree "$@"'

NSStringVariations.m

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        void (^benchmark)(const char *str) = ^(const char *str) {
            const long count = 10000000;
            NSDate *start = [NSDate date];
            for (long i = 0; i < count; i++) {
                (void)[[NSString alloc] initWithUTF8String:str];
            }

steipete

NSString *const PSPDFApplicationDidReceiveMemoryWarningNotification = @"PSPDFApplicationDidReceiveMemoryWarningNotification";

// Test with sudo memory_pressure -l critical. Don't forget to re-set afterwards!
__attribute__((constructor)) static void PSPDFInstallLowMemoryNotificationWarningMac(void) {
    static dispatch_source_t source;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        source = dispatch_source_create(DISPATCH_SOURCE_TYPE_MEMORYPRESSURE, 0, DISPATCH_MEMORYPRESSURE_WARN|DISPATCH_MEMORYPRESSURE_CRITICAL, dispatch_get_main_queue());
        dispatch_source_set_event_handler(source, ^{
            dispatch_source_memorypressure_flags_t pressureLevel = dispatch_source_get_data(source);