ObjC-Lua

A simple Objective-C <-> Lua bridge modeled after iOS 7's JavaScriptCore.

A trivial use might look like this:

static NSString *const myScript =
LUA_STRING(
           globalVar = { 0.0, 1.0 }

           function myFunction(parameter)
               return parameter >= globalVar[1] and parameter <= globalVar[2]
           end

           return globalVar[1], globalVar[2]
);

- (void)doLua {
	LuaContext *ctx = [LuaContext new];
	NSError *error = nil;

	NSArray *limits = [ctx parse:myScript error:&error];
	if( error ) {
		NSLog(@"Error parsing lua script: %@", error);
		return;
	}

	NSLog(@"globalVar is: %@", ctx[@"globalVar"]); // should print "globalVar is: [ 0.0, 1.0 ]"
	NSLog(@"with limits: [ %@, %@ ]", limits[0], limits[1]); // should print "with limits: [ 0.0, 1.0 ]"

	id result = [ctx call:@"myFunction" with:@[ @0.5 ] error:&error];
	if( error ) {
		NSLog(@"Error calling myFunction: %@", error);
		return;
	}
	NSLog(@"myFunction returned: %@", result); // should print "myFunction returned: '1'"

	ctx[@"globalVar"] = @[ @0.2, @0.4 ];

	result = [ctx call:@"myFunction" with:@[ @0.5 ] error:&error];
	if( error ) {
		NSLog(@"Error calling myFunction: %@", error);
		return;
	}
	NSLog(@"myFunction returned: %@", result); // should print "myFunction returned: '0'"
}

A more complex use might be:

static NSString *const myScript =
LUA_STRING(
           function moveView(view)
               local center = view.center
               center.y = center.y + 5
               center.x = center.x + 5
               view.center = center
           end
);

@protcol UIViewLuaExports <LuaExport>

@property(nonatomic) CGFloat alpha;
@property(nonatomic) CGRect bounds;
@property(nonatomic) CGPoint center;
@property(nonatomic) CGRect frame;

- (void)removeFromSuperview;

@end

@interface UIView (UIViewLuaExports) <UIViewLuaExports>
@end
@implementation UIView (UIViewLuaExports)
@end

- (void)doLua:(UIView*)onView {
    LuaContext *ctx = [LuaContext new];
    NSError *error = nil;
	
	[ctx parse:myScript error:&error]
    if( error ) {
        NSLog(@"Error parsing lua script: %@", error);
        return;
    }

    [ctx call:@"moveView" with:@[ onView ] error:&error];
    if( error ) {
        NSLog(@"Error calling myFunction: %@", error);
        return;
    }
}