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An implementation of Smalltalk-style CodeBlocks in Objective-C. At its guts is, for all intents and purposes, an Objective-C interpreter. This object enables HigherOrderMessaging, and creation of blocks is pretty easy, using OCBlock.h’s ocblock() and ocblockc() macros.

[collection do:ocblock(:each [each doSomething]; [self doSomethingWith:each];)];

If you’re only using class objects, self, numerical or boolean constants, arguments (inclusive-)or block-local variables in your block, it’s also ok to just use ocblock(). ocblockc() is a variadic macro that allows you to specify context keys(see OCBlock’s test cases).

It’s also possible to pass in your own OCBlockContext object using +[OCBlock blockWithString:inContext:].

Blocks can take arguments, which is really neat. They can have local variables, too.

Currying is also available with OCBlock, via the ‘- assumeValue:aValue forArgumentNamed:aName’ and ‘- assumeValue:aValue atIndex:(int)anIndex’ methods. An example of currying is to prevent the overhead of multiple parsings of a block by parsing once and then assuming the arguments where necessary, as per:

This will return the first object in elements that is equal to anObject, or nil if none is equal.

OCBlocks can only deal with object values and BOOLs(which are automatically converted to OCBooleans). At block parsing time, numerical constants will be turned into NSNumbers, and BOOL constants into OCBooleans.

The most recent revision of OSFoundation is tarred and gzipped and available at This includes OCBlock.

–JoeOsborn, of OpenSwordGroup.

**Er… I see it empty :’( ** – l0ne aka EmanueleVulcano

Linkrot is a terrible thing. I’ll try and hunt down an archived copy somewhere – sorry it’s been lost! A lot of uses of it, though, are being subsumed by KVC; -collect, for instance, is now implied by NSArray’s -valueForKey:. RobRix has a neat forall macro as well, inspired by AllanOdgaard:

#ifndef forall #define forall(collection, element) for(id _ ## element ## enumerator = [collection objectEnumerator], element; element = [ ## element ## _enumerator nextObject]; ) #endif

I should note that the only real difference between Allan’s version from his blog and my version here is the ## element ## stuff which lets you nest them. Allan did the interesting bit, I just slapped some putty on the side. Yeaaaah, putty. - RobRix

So, I’ll repost in the next few days, but there are alternatives to blocks now. The burning need isn’t there so much these days. – JoeOsborn