Hi,
I am currently building an iOS app with Gambit and I (of course) need a REPL-server in it so I can develop interactively instead of recompiling the app every time I make a change.
I saw the REPL-server that Marc developed in the iOS example folder of Gambit distribution so I tried to integrate it in my app. I was able to make it work but I have some problems.
When I first tried it I tried to run the repl server in a separate gambit thread. I therefore defined the following:
(c-define (init-repl-server) () void "initREPLServer" ""
; Start a REPL server
(thread-start!
(make-thread
(lambda ()
(display "\n\nStarting REPL server on port 7000\n")
(repl-server-start "toto")))))
In the objective-c method (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
I called the gambit setup and then the initREPLServer(); function.
This didn't work: when the C function returned the Gambit thread died (this is my interpretation) and I could not connect to the server.
I therefore tried put an infinite-loop at the end of the (init-repl-server) function. It worked but the app would not finish the startup process since "application didFinishLaunchingWithOptions"
call never returns YES as expected.
I then tried to run the scheme program in a separate thread (in that thread the call to (init-repl-server) in C would not have to return and would keep running).
[NSThread detachNewThreadSelector:@selector(initReplServer) toTarget:self withObject:nil];
I could then connect to the repl server but all assignments in objects are ignored by the interface loop since they are done in a separate thread. I then had the idea to use objective-c blocks (kind of closures in the objective-c world).
[[NSOperationQueue mainQueue] addOperationWithBlock:^{ object.slot=value; }];
This worked.... All the updates were now done in the GUI while working in the remote REPL. One day I tried to instantiate a UIWebView and the app crashed. UIWebView only works in the "main" thread.
I don't like the idea to have the REPL-server and Scheme program in a separate thread. So I tried to put just the REPL-server in a separate thread and run my actual scheme program in the main thread.
In this setup I could connect to the remote REPL but all the variables in the Scheme world are not pointing to the right memory location so everything is scrambled.
Is there a way out of this...? Can my program run in the main thread while still having a working remote REPL to debug it?
Thank you,
Francois Magnan
