Juillet 2009 - Gambit-list - mailman.iro.umontreal.ca

explicit pp
by Stéphane Le Cornec 24 Jul '09

24 Jul '09

Is there a way to explicitly pretty-print? Something like: > (display '(a XXX b c)) (a b c) > i.e. XXX outputs as some (newline) + spaces.

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remote debugger improvement
by James Long 24 Jul '09

24 Jul '09

Hey Marc (and other relevant readers), I found a bug with the remote debugger. At the end of a session with a client (the running program), when the client exits and disconnects from the remote debugger, the server halts with a "deadlock detection." This seems to always happen with any program, so I wonder if others are experiencing this. I think I figured out what's going on, and I'm offering a fix. If anyone has any opinions, let me know. The relevant changes affect how the server reads incoming connections. Before, it would create a server using OPEN-TCP-SERVER, wait for an initial connection, and establish the connection and then use THREAD-JOIN! from the primordial thread (thread A) to the writer thread (thread B) to wait for everything to finish. It seems like the design was to only have the server handle one client and then quit. The problem with this is that thread B wasn't terminated properly, and it sits there waiting for messages using THREAD-RECEIVE, while thread A is waiting for it to finish. Essentially, when the network connections quit and those threads die, you are left with thread A and B in a deadlocked situation. (That probably only makes sense to those who have studied Marc's remote debugger, which might only be Marc.) There are 2 solutions: 1. On the server, kill the writer thread at the appropriate time. This is probably when it receives the message that the reader thread has died, meaning that the client connection was lost. The server would simply exit. 2. Change the server so that it loops and continually accepts new client connections. It would only exit with a ^C. I think #2 is better server design. It seems like it should stay open, continually accepting new connections. This makes it very usable as simply a background process. Here are my changes to implement #2. You simple need to replace RDI-OPEN-SERVER with this one: (define (rdi-open-server rdi) (let ((listen-port (open-tcp-server (list port-number: (rdi-port-num rdi) reuse-address: #t)))) (let loop () (let ((connection (read listen-port))) (let ((request (read connection))) (if (not (equal? request rdi-version1)) (error "unexpected debuggee version") (begin (write rdi-version2 connection) (force-output connection) (let ((reader-thread (rdi-create-reader-thread rdi connection))) (rdi-connection-set! rdi connection) (thread-start! reader-thread) (loop))))))))) Now, the main thread doesn't to use THREAD-JOIN!, but it simply loops forever. So, the call (rdi-force-connection rdi) in debugger.scm never returns, but starts the loop. I've attached my current version of the remote debugger. It also features a different server interface; you pass in the host/port when running (gsi -:dar,h10000 debugger.scm 20000). - James

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keywords in standard mode
by Nguyen Thai Ngoc Duy 23 Jul '09

23 Jul '09

Hi, I'd like to show hidden files in standard mode. According to Gambit document, I need to use open-directory-port with ignore-hidden keyword but that wouldn't work in standard mode. Is there any way to make keywords work in standard mode, or another way to tell open-directory-port to list hidden files? Thanks, -- Duy

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Objective-C applications with Gambit
by Marc Feeley 19 Jul '09

19 Jul '09

Here's an interesting article on implementing Objective-C applications with Gambit on Mac OS X: http://mikelevins.livejournal.com/3298.html Thanks to Fabrizio Gotti for pointing this out (Fabrizio is one of the authors of the Gambit IDE "GUIDE"). Marc

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Slight improvment for the debugger interface?
by David St-Hilaire 18 Jul '09

18 Jul '09

Hello Gambit-list and Marc! I would have a simple request to enhance debugging in gambit. I often find myself to print backtraces, environments, etc to end up wondering "What was the error message again?". Then I always need to scroll back up to get it. Would it be possible to add a new , command like ,error or something like that so that it can redisplay the last error message again? Is this error in a dynamic variable so that I can print it myself? Thanks! David

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Fwd: [Gambit-iphone] emacs/slime repl integration
by James Long 17 Jul '09

17 Jul '09

Hey everyone, We've been discussing integrating Gambit and the remote debugger with SLIME on the gambit-iphone mailing list. Marc suggested moving the discussion here, and I agree with him. Here's the discussion; the context is using Marc's remote debugger for debugging iphone apps, but it's relevant for debugging any app. Please chime in if you have experience with SLIME or Emacs. ---------- Forwarded message ---------- From: James Long <longster(a)gmail.com> Date: Fri, Jul 17, 2009 at 12:35 AM Subject: Re: [Gambit-iphone] emacs/slime repl integration To: Ryan Spangler <ryan.spangler(a)gmail.com> Cc: gambit-iphone(a)iro.umontreal.ca On Thu, Jul 16, 2009 at 6:53 PM, Ryan Spangler<ryan.spangler(a)gmail.com> wrote: > So after using the repl for some time, it has become clear that it needs to > be integrated into emacs. For one, copy/paste on the mac doesn't work with > X11, and beyond that, if it was in emacs I could develop the whole program > in the repl, and save the relevant bits to a file afterwards. An ideal way > to develop. > > I'm not too up on emacs internals, anyone have any idea what it would take? > Could slime read from the repl's port? If we are lucky this wouldn't even > be too much work, I am just wondering how to begin? Any guidance would be > greatly appreciated, thanks! You are absolutely right, it's a step that has to be taken. I am in the same boat as you, though. I don't have very much Emacs wizardry, nor have I used SLIME (which seems like a beast). However, I've always wanted to learn how to write Emacs modes and do exactly this kind of thing. I plan on writing a mode for iphone development and debugging. I have it schedule for the end of next week, and I will let you know of my progress. If anyone else wants to try using SLIME instead, you are more than welcome to! - James

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Re: [gambit-list] Changing the console port settings dynamically?
by Arthur Smyles 16 Jul '09

16 Jul '09

> Note 2: I guess it is time to add procedures to get the stdin/stdout/ > stderr, e.g. (stdout-port) to get the standard output. Do other > Scheme implementations have an established naming convention for these > procedures? R6RS uses these: (standard-input-port) (standard-output-port) (standard-error-port) Arthur

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Black Hole and Termite
by Jeremie Lasalle Ratelle 16 Jul '09

16 Jul '09

I implemented vector pattern matching in termite some time ago. I'm trying to port my code in the black hole version of termite but there is a problem with vectors in macro code. Here is an example (define-syntax macro-test (sc-macro-transformer (lambda (form env) (pp form) `(begin)))) > (macro-test '(1 2 3)) (macro-test '(1 2 3)) > (macro-test #(1 2 3)) (macro-test #(#(#(source1) 1 (console) 917509) #(#(source1) 2 (console) 1048581) #(#(source1) 3 (console) 1179653)))

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Changing the console port settings dynamically?
by David St-Hilaire 16 Jul '09

16 Jul '09

Hi all! Is it possible to change the stdout port settings at runtime? I would like to be able to output some utf strings without having to start gambit with the utf-8 flag when launching gsi/gsc... is this possible? Thanks ^_^Y David

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Black Hole and key parameters
by Vincent St-Amour 16 Jul '09

16 Jul '09

I've been playing around with Black Hole recently (which is quite nice, by the way), and noticed the following issue. Importing a file that contains : (define (f x #!key (y x)) (+ x y)) (display (f 3)) Causes this error : > (import foo) *** ERROR IN ##main -- (Argument 2) NUMBER expected (+ 3 #!unbound) > y is unbound, while it should have the same value as x. Since there seems to be a problem with both of Black Hole's git repositories at the moment, I have not tested this with the latest version. If this has already been solved, sorry. Vincent

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