Nikodemus Siivola nikodemus

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ssh! it's a secret! foolang.org

nikodemus / split_closures.foo

Last active July 19, 2021 16:01

Splitting a file in Foolang

	---
	First 'scripting' excursion in Foolang!

	Input is file containing stuff like this:

	CLOSURE 1:
	args: ["out"]
	body:
	(self
	displayOn: out)

nikodemus / bt.lisp

Last active July 14, 2022 05:46

Showing why conditions are a bad match for doing backtracking -- all you need is CATCH/THROW and a special variable.

	;;;; In response to:
	;;;;
	;;;; http://www.reddit.com/r/lisp/comments/3710zq/directed_procrastination_backtracking_with_the/
	;;;; http://directed-procrastination.blogspot.se/2011/05/backtracking-with-common-lisp-condition.html
	;;;;
	;;;; Demonstrating why one should not use conditions for this kind of stuff,
	;;;; instead using the dynamic binding and unwinding facilities on which the
	;;;; condition system is built. The author's backtracking system doesn't compare
	;;;; badly to Screamer because his is simple: it compares badly because using
	;;;; conditions is a bad match for the task.

nikodemus / :MADEIRA-PORT and FEATURE-EVAL

Created May 7, 2012 05:36

something to chew on

	;;;; By Nikodemus Siivola <nikodemus@random-state.net>, 2012.
	;;;;
	;;;; Permission is hereby granted, free of charge, to any person
	;;;; obtaining a copy of this software and associated documentation files
	;;;; (the "Software"), to deal in the Software without restriction,
	;;;; including without limitation the rights to use, copy, modify, merge,
	;;;; publish, distribute, sublicense, and/or sell copies of the Software,
	;;;; and to permit persons to whom the Software is furnished to do so,
	;;;; subject to the following conditions:
	;;;;

nikodemus / foo-duplicates.lisp

Created April 19, 2012 19:01

this was what i had in mind

	(defconstant +foo-count+ (ash (sb-int:power-of-two-ceiling
	(* 8 sb-vm::backend-page-bytes))
	-1))

	(defconstant +foo-mask+ (1- +foo-count+))

	(defun foo-duplicates (list)
	(let ((bitmap (make-array +foo-count+ :element-type 'bit))
	(results nil))
	(declare (dynamic-extent bitmap))

nikodemus / gist:2331850

Created April 7, 2012 20:17

Recompiling stale fasls

	;;; If a fasl was stale, try to recompile and load (once).
	(defmethod asdf:perform :around ((o asdf:load-op)
	(c asdf:cl-source-file))
	(handler-case (call-next-method o c)
	(sb-ext:invalid-fasl ()
	(asdf:perform (make-instance 'asdf:compile-op) c)
	(call-next-method))))

nikodemus / broken-weight.lisp

Created November 30, 2011 22:22

The Broken Weight Problem

	;;;; Inspired by http://directed-procrastination.blogspot.com/2011/11/broken-weight-problem.html
	;;;;
	;;;; An example of using a generator to make your nondeterminism read nice.

	(in-package :screamer-user)

	(defun a-subset (set)
	"Non-deterministically returns all the subsets of SET, including the empty set NIL."
	(when set
	(either

nikodemus / condition-wait-gotcha.lisp

Created August 16, 2011 13:10

CONDITION-WAIT gotcha

	(with-lock (lock)
	(unwind-protect
	;; Calls CONDITION-WAIT on the lock
	(foo)
	;; If FOO unwinds, the lock it might not be held here!
	(bar)))

nikodemus / condition-wait-sketch.lisp

Created August 16, 2011 12:49

user-space CONDITION-WAIT sketch

	(defun condition-wait (waitqueue lock &key timeout)
	(release-lock lock)
	(let ((self current-thread))
	(unwind-protect
	(progn
	(enqueue self waitqueue)
	(when (wait-for (eq self (queue-first waitqueue))
	:timeout timeout)
	(grab-lock lock :timeout timeout)))
	(delete-from-queue self))))

nikodemus / irc.txt

Created November 2, 2010 11:19

Notes re. debugging Common Lisp with SBCL and Slime

	Context from IRC logs for future reference.

	[12:36] <kushal> nikodemus, can you point me to some tutorial on debugging on sbcl ?
	[12:37] * andreer (andreer@flode.pvv.ntnu.no) has joined #quicklisp
	[12:38] <nikodemus> kushal: no really good ones actually exist at the moment. i'm planning on writing one before the year is out, but... in the meanwhile, i can give some pointers
	[12:38] <nikodemus> a couple of questions: is this a general question, or do you have a specific issue you need to debug?
	[12:39] <kushal> right now , general, managed to debug the specific issue somehow :)
	[12:39] <nikodemus> ok. are you using slime?
	[12:39] <kushal> nikodemus, yes and no both
	[12:40] <nikodemus> good. :)