churchofthought

I just finally had my mind snap into place with understanding of the Y Combinator. Most explanations I read, even the ones using JS, didn't make much sense and were overly long so here follows my own, much simpler explanation. I will be using JS.


We have fibonacci to start with, very simple recursive function.
It's fixed points are 0 and 1, fib(0) = 0, and fib(1) = 1
That's all a fix point means, when the f(x) == x
They are important because they are the only values at which recursion can cease.

Our Fibonacci Function
======================

churchofthought

I just finally had my mind snap into place with understanding of the Y Combinator. 
Most explanations I read, even the ones using JS, didn't make much sense and were 
overly long so here follows my own, much simpler explanation. I will be using JS.


We have fibonacci to start with, very simple recursive function.
It's fixed points are 0 and 1, fib(0) = 0, and fib(1) = 1
That's all a fix point means, when the f(x) == x
They are important because they are the only values at which recursion can cease.

churchofthought

AsyncBlockOperation is very similar to NSBlockOperation with one caveat; the block you pass to it receives one argument, a reference to the AsyncBlockOperation for the block. When your block is done with its task, it must call [op complete]


Example usage:

NSOperation* asyncOp = [AsyncBlockOperation blockOperationWithBlock:^(AsyncBlockOperation* op) {
    NSLog(@"starting op");
    double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){

churchofthought

NSLog(@"%@", OR(nil,@"", @{@"foo": @"bar"}, @[]));
// outputs {foo = bar;}

NSLog(@"%@", OR(nil,@"", @{}, @[]));
// outputs []

NSLog(@"%@", OR(nil,@"", @[], @"", @{}));
// outputs {}

NSLog(@"%@", OR(nil,@"", @[], @"", nil));

churchofthought

#ifndef XIBXOR_OR
//
//  XXOr.h
//
//  Created by XibXor on 5/5/13.
//
//  Non-coalescing OR macro for variable arguments and variable types including objects/primitives.
//  Similar to || behavior in ECMAScript
//
//  Usage: OR(a,b,...)

churchofthought

//
//  XXOr.h
//
//  Created by XibXor on 5/5/13.
//
//  Non-coalescing OR macro for variable arguments and variable types including objects/primitives.
//  Similar to || behavior in ECMAScript
//
//  Usage: OR(a,b,...)
//

churchofthought

void strrev(char *strStart, const int len){
    
    char* strEnd = strStart + len;
    
    while (strStart <= (strEnd -= 8)){
        
        __uint64_t buf = *(__uint64_t*)strStart;
        
        *(__uint64_t*)strStart = *(__uint64_t*)strEnd;
        __asm__ ("bswap %0" : "=r" (*(__uint64_t*)strStart) : "0" (*(__uint64_t*)strStart));

churchofthought

comment *==========================================
  jagHook
	
	Note that:
		macros are like win32 api; they may modify all registers but ebx, edi, esi
		your .text section needs to be writable if using the non-procedural hooking
			if using radasm, add /SECTION:.text|RWE the LINK box under Project -> Project Options]
			otherwise, just add /SECTION:.text,RWE to linking arguments

churchofthought

comment *==========================================
  jagHook by jAgx
	
	Note that:
		macros are like win32 api; they may modify all registers but ebx, edi, esi
		your .text section needs to be writable if using the non-procedural hooking
			if using radasm, add /SECTION:.text|RWE the LINK box under Project -> Project Options]
			otherwise, just add /SECTION:.text,RWE to linking arguments

churchofthought

comment *==========================================
  jagHook
  
	Note that:
		macros are like win32 api; they may modify all registers but ebx, edi, esi
		your .text section needs to be writable if using the non-procedural hooking
			if using radasm, add /SECTION:.text|RWE the LINK box under Project -> Project Options]
			otherwise, just add /SECTION:.text,RWE to linking arguments