jspahrsummers

/// Observes a run loop to detect any stalling or blocking that occurs.
///
/// This class is thread-safe.
@interface GHRunLoopWatchdog : NSObject

/// Initializes the receiver to watch the specified run loop, using a default
/// stalling threshold.
- (id)initWithRunLoop:(CFRunLoopRef)runLoop;

/// Initializes the receiver to detect when the specified run loop blocks for

jspahrsummers

How to use asynchronous generators

The documentation 6.2.9.4. "Asynchronous generator-iterator methods" is phrased really ambiguously. To make matters worse, typing.AsyncGenerator is not specified fully correctly.

Here, I attempt to more clearly capture the actual interface contract, based on what I've read and observed. See also PEP 492 -- Coroutines with async and await syntax and PEP 525 -- Asynchronous Generators.

This might be useful to implement lower-level behaviors than you can with async for, like sending values into the generator function.

TSend = TypeVar('TSend', contravariant=True)

jspahrsummers

template<typename Left, typename Right>
struct Intersect
{
  // This will fail to compile if there's no specialization for Intersect<Right, Left>,
  // thereby verifying that we've handled all combinations.
  typename Intersect<Right, Left>::Result operator() (const Left &lhs, const Right &rhs) const
  {
    return Intersect<Right, Left>()(rhs, lhs);
  }
};

jspahrsummers

Dear Customer,

I am Randy Jacops, the CEO of Idera, Inc. You likely saw the press announcement last month announcing Idera’s acquisition of Travis CI (hereafter, Travis). Here is a link to the announcement if you have not seen it: Idera, Inc. Acquires Travis CI GmbH for Continuous Integration Capabilities.

I’d like to welcome you to the Idera family and look forward to building on Travis’ history of market leading continuous integration products for software developers and testing professionals. I’m writing this letter to introduce Idera and explain why we are excited to acquire Travis.

Idera delivers B2B software productivity tools that allow technical users to do more with less, faster. The company's brands span three divisions—Database Tools, Developer Tools and Testing Tools—with products used and evangelized by millions of community members and more than 50,000 customers worldwide. Continuous integration accelerates software delivery, improves developer productivity, and enables technical innovation t

jspahrsummers

Simple visual illustrations of how CGRectDivideWithPadding works.

Slicing from CGRectMinXEdge

  +-------+---------+------------>
e |       |         |
d | slice | padding | remainder…
g |       |         |
e |       |         |

jspahrsummers

//
// DON'T do this, or else you risk a deadlock (e.g., by accidentally performing it in a different order somewhere)
//

dispatch_async(firstQueue, ^{
  dispatch_sync(secondQueue, ^{
    // code requiring both queues
  });
});

jspahrsummers

#define $(...) \
    ({ \
        __weak __typeof__(self) weakSelf = self; \
        \
        ^(__VA_ARGS__) { \
            __strong __typeof__(weakSelf) self = weakSelf; \
            $_body_

#define $_body_(...) \
            __VA_ARGS__ \

jspahrsummers

MVVM example

For a command that initiates a network request when:

• The network connection is up (precondition)
• The network request is not already in progress (enforced serialization)

The lifecycle proceeds as follows:

1. The view model exposes the command and describes its behavior

jspahrsummers

#import <Foundation/Foundation.h>

int main (int argc, const char **argv) {
  @autoreleasepool {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
      dispatch_sync(dispatch_get_main_queue(), ^{
        NSLog(@"is main thread? %i", (int)[NSThread isMainThread]);
      });
    });

jspahrsummers

#define ObjectKeyPath(OBJECT, KEYPATH) \
    ((void)(NO && ((void)OBJECT.KEYPATH, NO)), @ # KEYPATH )

NSString *str = @"foobar";
NSLog(@"%@", [str valueForKey:ObjectKeyPath(str, length)]);