August 2008 - MSLUG - mailman.iro.umontreal.ca

MSLUG Meeting *this* Wednesday, August 27th at 7pm -- Space Edition
by Guillaume Germain 28 Aug '08

28 Aug '08

Hi everybody, this is a reminder for the meeting of the MSLUG this week. What: Montreal Scheme/Lisp User Group Meeting -- Space Edition When: *Wednesday* August 27th 7pm Where: Room 3195, André-Aisenstadt Building, Université de Montréal, 2920 chemin de la Tour (you can find a plan of the UdeM campus here: http://www.stcum.qc.ca/metro/images/c56.pdf) There will be two presentations of about 30 minutes each: * Vincent St-Amour -- Small Scheme Stack: a Scheme TCP/IP stack targeting small embedded applications Vincent has worked on an optimized-for-space TCP/IP stack in Scheme. He will give us the same presentation that he will eventually give to the Scheme Workshop in Victoria later this year. You can see an abstract of his presentation here: http://www.ccs.neu.edu/home/will/scheme2008/abstract.stamour.html * David St-Hilaire -- An implementation of Space Invaders for Gambit-C In the context of his Masters, David has implemented a clone of the classic Space Invaders arcade game. He will give us a demonstration of his game and discuss its architecture and implementation. You can try David's game by downloading it here: http://www-etud.iro.umontreal.ca/~sthilaid/ As usual, everybody is welcome and we will go for a beer after the presentations, likely at the pub St-Hubert on Côte-des-Neiges. See you Wednesday! Guillaume

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Strange behaviour explained
by Marc Feeley 28 Aug '08

28 Aug '08

For those who were there during my demo of "wills" at the MSLUG meeting... the strange behaviour with collection of bignums has nothing to do with the reciprocal-cache (indeed it is correctly managed with a table with weak references), nor is it related to bignums. It is really a byproduct of the recent result table which remembers the last 3 results of the REPL, so that they can be accessed with the forms # (last result), ## (penultimate result) and ###. In the example below the bignum 1000000000000000000000000000000 which was reachable through variable "a" is still reachable after the (set! a #f) because it is still in the recent result table. A few dummy expressions have to be entered so that bignum is dropped from the table. I remember feeling uncomfortable when introducing the REPL recent result history because of the temporary space leak. Now I know why... Marc Gambit v4.2.8 > (define a (expt 10 30)) > (make-will a (lambda (x) (pp (list 'died: x)))) #<will #2> > a 1000000000000000000000000000000 > (set! a #f) > (##gc) > (##gc) > 111 111 > 222 222 > 333 333 > (##gc) (died: 1000000000000000000000000000000)

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MSLUG Meeting next Wednesday, August 27th at 7pm -- Space Edition
by Guillaume Germain 19 Aug '08

19 Aug '08

Hi everybody, this is an announce for the next meeting of the MSLUG. What: Montreal Scheme/Lisp User Group Meeting -- Space Edition When: *Wednesday* August 27th 7pm Where: Room 3195, André-Aisenstadt Building, Université de Montréal,2920 chemin de la Tour (you can find a plan of the UdeM campus here: http://www.stcum.qc.ca/metro/images/c56.pdf) Two presenters have volunteered for what should be a very interesting night: * Vincent St-Amour -- Small Scheme Stack: a Scheme TCP/IP stack targeting small embedded applications Vincent has worked on an optimized-for-space TCP/IP stack in Scheme. He will give us the same presentation that he will eventually give to the Scheme Workshop in Victoria later this year. You can see an abstract of his presentation here: http://www.ccs.neu.edu/home/will/scheme2008/abstract.stamour.html * David St-Hilaire -- An implementation of Space Invaders for Gambit-C In the context of his Masters, David has implemented a clone of the classic Space Invaders arcade game. He will give us a demonstration of his game and discuss its architecture and implementation. You can try David's game by downloading it here: http://www-etud.iro.umontreal.ca/~sthilaid/ As usual, everybody is welcome and we will go for a beer after the presentations. See you next Wednesday! Guillaume

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Paul Graham's OnLisp
by Jean-Philippe Barrette-LaPierre 05 Aug '08

05 Aug '08

For those that would be interested in buying Paul Graham's OnLisp, which is out of print, it's available on lulu.com: http://www.lulu.com/content/3102787 I just received my copy. Beautiful book, only around 40$. Took me 2 weeks to receive my copy. -- Jean-Philippe Barrette-LaPierre

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