VeritasKit

Lua bind for Objective-C, implemented most Objective-C features

TODOs

1. support for class-ivar, you can not access to ivar by name (for example, _ivarName) in method block
2. full support of block, block is almost fully supported excepted some wired condition

Features

1. support most Objective-C syntax features, which is simillar to Objective-C progammers(such as @autoreleasepool);
2. support lua syntax, so we may call this Objective-Lua;
3. support new Objective-C syntax, such as literal NSDictionary, literal NSArray, literal NSNumber, syntax of literal NSDictionary is not the same as in Objective-C, consider the lua syntax;
4. support enumerate syntax of collections (the for-in syntax);
5. add some extensions, such as @array, @dictionary, @table to convert value between Objective-C and lua;
6. speed up by store global value in a strong table in lua state, so updated the benchmark table below;

Known Bugs

1. no try-catch-final, @throw implemented, but not that good, recommanded not to use this feature;
2. will not support dot-operator (.) on instance, which is my decision;

What we know

1. I have used this framework in one of my comercial project, it works well

2. Benchmark test result on iPod Touch 4, software version: 5.1.1 :

   run +[NSString stringWithUTF8String:] 100,000 times, average cost

   NSInvocation	2.621619s
   libffi	1.007282s
   Lua-Call	12.943947s

   code:

   
   static const char * _testString = "你好";
   
           static void testInvocation()
           {
              Method method = class_getClassMethod(objc_getMetaClass("NSString"), @selector(stringWithUTF8String:));
              const char *encoding = method_getTypeEncoding(method);
   
              NSMethodSignature *sig = [NSMethodSignature signatureWithObjCTypes: encoding];
              NSInvocation *invocation = [NSInvocation invocationWithMethodSignature: sig];
              [invocation setTarget: [NSString class]];
              [invocation setSelector: @selector(stringWithUTF8String:)];
              [invocation setArgument: (void*)&_testString
                              atIndex: 2];
              [invocation invoke];
              NSString *returnValue = nil;
              [invocation getReturnValue: &returnValue];
   
              //printf("returnValue: %s\n", [returnValue UTF8String]);
           }
   
           static id _testIMP(id obj, SEL selector, const char \*aString)
           {
              return [NSString stringWithUTF8String: aString];
           }
   
           static void testFFI(void)
           {
              Class metaClass = objc_getClass("NSString");
              SEL selector = @selector(stringWithUTF8String:);
   
              IMP impRef = class_getMethodImplementation(objc_getMetaClass("NSString"), selector);
   
              ffi_cif cif;
              ffi_type *argTypes[3];
              void *args[3];
   
              /* Initialize the argument info vectors */
              argTypes[0] = &ffi_type_pointer;
              argTypes[1] = &ffi_type_pointer;
              argTypes[2] = &ffi_type_pointer;
   
              args[0] = &metaClass;
              args[1] = &selector;
              args[2] = &_testString;
   
              /* Initialize the cif */
              if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 3, &ffi_type_pointer, argTypes) == FFI_OK)
              {
                    NSString *returnValue = nil;
                    ffi_call(&cif, FFI_FN(impRef), &returnValue, args);
                    //printf("returnValue: %s\n", [returnValue UTF8String]);
              }
           }
   
           static void testLuaCall(void)
           {
                 static NSString * const sourceCode = @"local invoke = function() local a = [NSString stringWithUTF8String:\"你好\"] [a release] end\n"
                                     "testLuaCall = function() for i=1, 100000 do invoke() end end";
   
                 LuaCall(sourceCode, @"testLuaCall", nil, 0, 0, nil);
           }
   
   

Example Code

1.Used in projects

function initialize(self)
local animationViews = [self animationViews];
local resourcePath = [[self resourceBasePath] stringByAppendingPathComponent: @"/1/"];
local sharedResourcePath = [[self resourceBasePath] stringByAppendingPathComponent: @"/Shared/"];
local imageFilePath = [resourcePath stringByAppendingPathComponent: @"textContent.png"];
local textContentImageView = [[UIImageView alloc] initWithImage: [UIImage imageWithContentsOfFile: imageFilePath]];
[textContentImageView setFrame: CGRectMake(40, 150, 397, 250)];
[self addSubview: textContentImageView];
[textContentImageView release];

			               [animationViews setObject: textContentImageView 
							                      forKey: @"textContentImageView"];
	         end
    					
           function slideAnimationFunction(self)
		                  local animationViews = [self animationViews];
              			local titleView = [animationViews objectForKey: @"titleView"];
		                  local contentView = [animationViews objectForKey: @"contentImageView"];
		
		                  [UIView animateWithDuration: 0.5
						                       animations: (^()
									                           {
											                           [titleView setAlpha: 1];
									                           })
						                       completion: (^(BOOL finished)
									                           {
											                           [contentView setAlpha: 1];
									                           })];
                    end 
  </code></pre>