Zach Beane's Blog

Boston Lisp Meeting on May 23

xach@xach.com — Wed, 22 May 2013 12:26:16 GMT

Boston Lisp meetings are a lot of fun. Here's Alex Plotnick's announcement for the next meeting:

I'm pleased to announce that François-René Rideau will speak at the next Boston Lisp meeting on his recent work on ASDF 3. The meeting will take place on Thursday, 23 May at 6:30 PM, in the Star Conference room at MIT's Stata Center (MIT 32-D463; <http://whereis.mit.edu/?go=32>).
I'm sorry about the short notice on this one; communications problems of all kinds have been gumming up the works. Please feel free to spread the word about the meeting via whatever mechanisms are available to you.
Talk details (courtesy of Faré) follow. I hope to see you all there!
Title: "ASDF 3, or lessons in building portable Common Lisp programs"
Summary:
"ASDF (Another System Definition Facility) has been the de facto standard Common Lisp build system for over ten years. I recently rewrote it completely, several times, all the time (mostly) preserving backwards compatibility. The latest incarnation, ASDF 3, in addition to fixing deep design bugs older than ASDF itself, also includes extensive portability library, UIOP, not to be confused with an existing parallelizing extension, POIU. I will show how to use ASDF, explain the recent improvements, and discuss the challenges of writing portable Common Lisp programs and what that means for the past and future of Lisp."
About the speaker:
"François-René Rideau is a Lisp plumber. On good days, he designs great piping for persistent data, to be used in airline reservation system of ITA (now part of Google). On bad days, he dons his rubber gloves and scrubs the pipes. He also has a blog, Cybernethics, where he writes on liberty, music, programming, and dynamic systems in general."

I can't make it, but if you're in the Boston area, you should go!

xach@xach.com — Tue, 14 May 2013 12:57:26 GMT

Yesterday around 4PM the phone rang, and came up UNKNOWN NUMBER on the caller id. Those are never worth answering, but I picked up anyway.

Hello? "Hello, this is Jack," said a heavily accented voice, "This is the second call about the slow performance and possible virus problems of your Windows PC."

I don't have one of those, is what I thought, but what I said was, Ok, yeah, I have had a lot of problems lately. "Well sir I am calling to assist you with those problems, is the PC on right now?" Yeah, sure. "Ok, sir, can you please go to your PC."

Ok, I'm at my PC. "Now in the LOWER, LEFT corner of the screen, do you see a Windows button?" Windows button? What's that? "It looks like a flag." What color flag? "It is a flag in the corner." Which corner? What color is it?

Jack is starting to sigh. "In the LOWER, LEFT corner." I don't see a button anywhere. "It is in the corner sir." OH! I see the button!

Jack gets happier. "Now do you see Computer or My Computer in the menu that pops up?" I don't see any menu. "You have to click the Windows button." Where is that? More sighs. "In the lower left corner." OH! Ok, I clicked it! "Do you see Computer or My Computer in the menu?" I can't see YOUR computer! I'm at my house! "No, do you see COMPUTER, or do you see MY COMPUTER?" I can't see your computer, that doesn't make any sense!

Jack sighs some more. "What do you see for menus?" OH! I see Computer there! "Ok, can you right-click on Computer, and..." I closed the menu. Sigh, sigh. "Can you open the menu again and right-click on..." Where am I supposed to write it?

I can't stop laughing any more, so I interrupt Jack and ask him how dumb he thinks I am. "VERY DUMB!" He is pretty mad. Jack, who are you calling from, who do you represent? "I am calling from Afghanistan!" And what company are you calling from? "I am Mozilla Firefox!" And what are you trying to do? "I am trying to HACK YOUR COMPUTER!" I just laugh and wish him good luck, and he says "Go to hell, you bastard!" and hangs up.

ECLM 2013 - two days left to register

xach@xach.com — Mon, 13 May 2013 17:33:31 GMT

Important news:

Subject: ECLM 2013 - two days left to register
Date: Mon, 13 May 2013 19:17:26 +0200
From: Edi Weitz
Ladies and Gentlemen,
This is our last call - there are two days left to register for this year's ECLM in case you haven't done so already:
http://weitz.de/eclm2013/
We have more than 50 registrations so far, but we wouldn't mind seeing another dozen or two...
Best regards,
Arthur & Edi.

I greatly enjoyed my last visit to ECLM and I can't recommend it highly enough if you want to meet people with interesting Common Lisp projects and ideas.

Lisp gatherings

xach@xach.com — Wed, 08 May 2013 19:13:26 GMT

I'm very excited to be attending both ECLM and ELS in Madrid this year. This is the last week to register for ECLM, so if you want to go, you should register ASAP.

jscl rising

xach@xach.com — Sun, 28 Apr 2013 16:17:40 GMT

I am impressed with the web-based jscl repl. Most Lisp web repls are for toy Lisps. I was so charmed that the first form I tried in JSCL, (make-package "FOO"), worked that I didn't mind that a lot of other stuff hasn't been implemented yet. I want to help hack on it to make it better!

A bunch of people have forked it on github to add more and more functionality, and I think jscl will just keep getting cooler. Good job, David Vázquez and contributors!

Quick and dirty progress tracking

xach@xach.com — Thu, 25 Apr 2013 02:39:33 GMT

Today I was running some analysis on about 9,000 files, basically mapping a function over each to warm up a cache. Something like this:

* (map nil 'analyze-file *9000-files*)
time passes

I had no idea how well it was progressing, and whether I'd need to take a snack break or let it run overnight. So I interrupted it and wrote a quick and dirty REPL utility function:

(defun :dot-every (count fun)
  (let ((i 0))
    (lambda (&rest args)
      (when (< count (incf i))
        (setf i 0)
        (write-char #\. *trace-output*)
        (force-output *trace-output*))
      (apply fun args))))

It prints out one dot per COUNT invocations of the function it returns, giving some indication of progress. Sensible values for COUNT depend on the volume of function calls.

For this problem, I called it with a COUNT of 100:

* (map nil (:dot-every 100 'analyze-file) *9000-files*)
............etc

The cached analyses printed out a ton of dots quickly, and the uncached analyses started printing dots at a slow but steady pace, and I could tell that it would be done in a few minutes instead of a few hours.

So now I'm going to use this to wrap up any function I have to call a ton of times and I want to get a sense of how it's progressing.

Maximum (Lisp) Overdrive

xach@xach.com — Sat, 16 Feb 2013 16:41:40 GMT

A long time ago Philip Greenspun wrote about a system to control bulldozers with Lisp Machines. You can read about it in his thesis, SITE CONTROLLER: A system for computer-aided civil engineering and construction.

The Rob Warnock Lisp Usenet Archive

xach@xach.com — Sun, 03 Feb 2013 02:38:27 GMT

I've been reading and enjoying comp.lang.lisp for over 10 years. I find it important to ignore the noise and seek out material from authors that clearly have something interesting and informative to say.

Rob Warnock has posted neat stuff for many years, both in comp.lang.lisp and comp.lang.scheme. After creating the Erik Naggum archive, Rob was next on my list of authors to archive. It took me a few years, but here it is: the Rob Warnock Lisp Usenet archive. It has 3,265 articles from comp.lang.lisp and comp.lang.scheme from 1995 to 2009, indexed and searchable. I hope it helps you find as many useful articles as I have over the years.

Here are a few articles I've saved and shared over the years:

There are many, many more, but I hope this gets you interested in finding some on your own Enjoy!

(In case you're curious, I used a library called usenet-legend to create the archive and make it searchable. I also have some unreleased code that provides a thin layer of web interface on top of usenet-legend.)

Dr. David McClain code release

xach@xach.com — Wed, 02 Jan 2013 16:18:51 GMT

Dr. McClain has been working on cool Common Lisp stuff for many years, and now he's starting to release some of his code.

Well, it has been more than 20 years with Lisp in earnest... I'm sitting on a gold mine of great code that I have
used over the entire period, and still use daily in my work. But it seems the Lisp community is a bit short on
libraries of code. No point sitting on all this stuff till I die...

One of the (many) great things I have found with Lisp is that Code Rot (I always called this Bit-Rot, but I
realize that I'm wrongly attributing when I do that) is almost a non-problem, compared to just about every
other language system that I have used in my 40+ year career. I'm still using a large body of code that I wrote
nearly 15-20 years ago and has never needed any maintenance.

My code generally grows organically to supply solutions to problems I am facing in my own work. I generally
don't write libraries for others to use. And that will show through in a lot of what I share with the world.
C'est la vie...

You can read the rest of his message on the lisp-hug archive. His github page is here.

CAPI demos from Dr. Weitz

xach@xach.com — Wed, 02 Jan 2013 14:07:50 GMT

Some interesting news from Edi:

The upshot in terms of Lisp evangelism has been quite good, BTW. Most
of the students have only been exposed to Java and scripting languages
so far and there are always some who express an immediate interest in
learning more about CL.

Read the full post here.

Glacier transition support added to ZS3

xach@xach.com — Thu, 20 Dec 2012 17:15:57 GMT

Amazon Glacier came out a few months ago. Glacier is a system for storing data very cheaply, only $0.01 per gigabyte per month. It also has a high level of redundancy and reliability. The drawback, compared to S3, is that you can't access it on demand. It was added as a new API, and I looked into writing a CL library for it, but never found the time.

A few days ago Amazon announced integration between S3 and Glacier. Objects in S3 can be automatically transitioned to Glacier storage after a period of time. It's very similar to the automatic object expiration support already present in the S3 API.

Since I already have an S3 library, I updated it to support the new Glacier features.

The lifecycle-rule function has been revamped to support a new action argument, :transition. Instead of deleting the object when the rule is applied, it is transitioned to Glacier storage.

New functions restore-object and object-restoration-status let you initiate a Glacier object restoration and query the status of that restoration.

Here's an example:

  (zs3:create-bucket "storage.xach.com")
  (setf (zs3:bucket-lifecycle "storage.xach.com") 
        (zs3:lifecycle-rule :action :transition 
                            :prefix "glacier/" 
                            :days 7))

Any object uploaded to the "storage.xach.com" with a prefix matching "glacier/" will be automatically transitioned to Glacier storage after 7 days. You can also use a :days option of 0, which means "transition as soon as possible." I tried that, and "as soon as possible" can mean hours. Apparently the process that does the transition does not run all the time.

After the object has transitioned, you can't retrieve it with functions like get-file:

  (zs3:get-file "storage.xach.com" "glacier/archive.tgz" "/tmp/archive.tgz")
  Error: "InvalidObjectState: The operation is not valid for the object's storage class"

The object has to be restored first. Restoring an object works like this:

  (zs3:restore-object "storage.xach.com" "glacier/archive.tgz" :days 1)

The "days" argument refers to the number of days the object is available for download before it automatically reverts back to Glacier storage.

Restoring an object can take several hours. To check on object's restoration status, you can do this:

  (zs3:object-restoration-status "storage.xach.com" "glacier/archive.tgz")
  => "ongoing-request=\"true\""

The next release of Quicklisp will have this ZS3 update. To get it early, you can check it out from github or download it from my website. Enjoy!

fast-io

xach@xach.com — Tue, 04 Dec 2012 15:13:28 GMT

fast-io looks pretty interesting.

Vagrant + CL

xach@xach.com — Tue, 27 Nov 2012 21:03:42 GMT

Here's something interesting from comp.lang.lisp:

From: Ruben Garcia Martin
Subject: Vagrantfile for Common Lisp
Newsgroups: comp.lang.lisp

Hi All,
For those of you who use Vagrant boxes for development, I have published a configuration to set up a minimal Common Lisp environment quickly here:
https://github.com/finitud/vagrant-common-lisp
Please feel free to use & comment.
Regards,
Ruben.

Postmodern examples

xach@xach.com — Tue, 27 Nov 2012 19:42:27 GMT

Here's a cool site of Postmodern examples from Sabra Crolleton.

mocl

xach@xach.com — Thu, 15 Nov 2012 00:27:44 GMT

mocl sounds interesting: mocl allows you to create applications for iOS, Android, and other mobile platforms using highly expressive Common Lisp code. mocl makes this possible by compiling your Common Lisp code to platform-portable, efficient C code. There aren't a lot of details but I'm looking forward to more information when it's available.

xach@xach.com — Tue, 13 Nov 2012 17:12:14 GMT

Tapiwa Gutu writes about developing a Grand Unified Unit Test Framework for Common Lisp: Part 1 and Part 2.

xach@xach.com — Fri, 09 Nov 2012 17:53:18 GMT

quickproject and cl-project compared.

cl-test-grid updates

xach@xach.com — Mon, 22 Oct 2012 16:53:11 GMT

From: Anton Vodonosov
Subject: library reports
Date: Sun, 14 Oct 2012 01:17:51 +0400

Hello.

Another usage of the results collected by cl-test-grid is
separate reports for every library in Quicklisp.

The results include build status for the library ASDF systems
and test-suite results (if the test suite has test-grid adapter)
on every lisp implementation we have tested.

The reports may be found at
http://common-lisp.net/project/cl-test-grid/library/<library name>.html

Index of all the reports: http://common-lisp.net/project/cl-test-grid/library/

PS

Xach, could you announce this on planet lisp?

Also:

Just published reports with October data (so far we collected
results of 7 CL compilers, in various compiler version/OS combinations
it is around 27 compiler kinds).

The most interesting report for you must be this one:
http://common-lisp.net/project/cl-test-grid/quicklisp-diff.html
It displays the all the tests which have different outcome
on September and October Quicklisps.

- Anton

A followup from Anton

xach@xach.com — Sun, 30 Sep 2012 00:37:54 GMT

From: Anton Vodonosov <avodonosov@yandex.ru>
Subject: Re: combining load failures with dependencies information to
 priorities fixes

Xach, could you please arrange the following
clarification to be forwarded to Planet Lisp? It's necessary
in particular to restore/confirm good names of ECL and Closer to MOP?

When I posted the first message in this thread and
CC'ed Xach, I wanted to present the results
cl-test-grid may provide, but I forgot that the results
deal with failures, and without proper explanation
it may cast shadow of bad impression onto someone's
hard work.

In this case ECL and Closer to MOP were mentioned
in context of large table of failures.

First of all. The absolute minority of the compile-load
failures presented in the report are bugs in ECL (if any).

The failures may be classified by their cause into:
- CL implementation bugs
- library bugs
- library intentionally supports only limited
  set of CL implementations
- absence of certain foreign library
  on the test system.

By priority for the lisp implementation maintainer:

1. CL implementation bugs are of course of interest
   for the maintainer.

   Here I want to say how they are handled in ECL.
   Of course, ECL can not be bug free, especially
   taken into account that in the recent years it saw
   major changes (fully rewritten Lisp-to-C compiler,
   newly introduced bytecode compiler, refactoring
   of multi-threading infrastructure, performance
   improvements and lot of other improvements).

   But when critical bugs are found, they are usually
   fixed very quickly. This demonstrates the great level
   of control Juan Jose has on the ECL code base.

2. Bugs in basic widely used libraries as alexandria;
   portability layers like closer-mop, usocket,
   bordeaux-threads; important libraries as
   hunchentoot or drakma.

   This is not the area of direct "responsibility"
   for the CL implementation developer who didn't started
   the project and didn't make a commitment to
   support it.

   I put "responsibility" into quotes because very
   often we deal with open source projects, which
   are provided AS IS. No-one is obliged to provide
   support. The applies also to the library author.

   Of course, CL implementation developer might
   be interested to support such important libraries
   to achieve wider adoption of his CL implementation.
   The library author is also usually interested.
   And the users of the library, who want to develop
   applications on the given CL implementation are
   also interested to see the library fixed on this CL
   implementation.

   So, this is an area where interest of various parties
   overlaps and we may hope the issue will be fixed
   (depending the time available for these parties
   and presence of necessary knowledge).

   Speaking particularly about Closer to MOP on ECL.
   ECL has improved MOP support recently, but the API
   changes are not backward compatible. According
   to the Pascal's comment in his blog, now Closer to MOP
   will need a lot less code to support ECL. But migration to the
   new API will take some development time.

3. Compile/load failures which do not need to be fixed.

   For a library developer it is often the only possible
   or at least the most reasonable solution to support
   limited set of CL implementations, because supporting
   and testing on every CL requires more time than available.

   If there is a library named "my-html-utils" which is
   only used by "my-web-application" and the library
   author works with one particular CL implementation,
   there is no need to bother neither the library author,
   nor other community members with requests to port
   the library onto other CL implementations.

   What we can do is to collect and provide information
   about what works where, and the author will decide
   himself. Or maybe the first user, who whats to
   employ the library on a different implementation
   will port it.   

   I assume that the failures in the category 3 might
   constitute the majority of all the failures.

4. Absence of foreign library on the test system.
   I plan to adjust cl-test-grid agent in the future
   so that CFFI errors will be recognized and
   stored as a special status, so that we will be
   able to exclude them from report + maybe collect
   the list of foreign libraries used by whole Quicklisp.
   But it's not the highest priority, the reports
   in the current form allow to make lot of useful
   conclusions.

That's it. I hope it clarifies any doubts about the
quality of work done by ECL and Closer to MOP developers.

And also on my intentions. I don't call the developers
to spend even more of their time. Other way around.
We should anticipate the fact that developers time is
very limited. If we all be realistic and stay within
limits of possible the results will be more satisfying.
I hope that presence of information will allow to
save developers energy by helping them to choose
areas where the efforts will give maximum outcome;
to decide also what may be avoided.

The load failures + dependencies report was build for
ECL first because it was Juan Jose's proposal to
combine them together to prioritize problems.

I've just published similar reports for some
other CL implementations I have:

http://common-lisp.net/project/cl-test-grid/abcl-load-failures.html
http://common-lisp.net/project/cl-test-grid/acl-load-failures.html
http://common-lisp.net/project/cl-test-grid/ccl-load-failures.html
http://common-lisp.net/project/cl-test-grid/cmucl-load-failures.html
http://common-lisp.net/project/cl-test-grid/sbcl-load-failures.html
http://common-lisp.net/project/cl-test-grid/ecl-load-failures.html

Best regards,
- Anton

xach@xach.com — Thu, 27 Sep 2012 15:26:15 GMT

Improving CL implementations with cl-test-grid

xach@xach.com — Tue, 25 Sep 2012 18:12:00 GMT

Anton Vodonosov has been doing fantastic work with cl-test-grid. Check out his message to the ECL maintainer showing which library fixes will result in the most bang for the buck.

Cruise ship leaves Casco Bay

xach@xach.com — Mon, 24 Sep 2012 01:15:10 GMT

Common Lisp quiz

xach@xach.com — Tue, 18 Sep 2012 18:42:44 GMT

A few years ago I started collecting random bits of Common Lisp trivia to use for a "purity test" of sorts. Progress has stalled, and some of the bits have turned into lisptips. I don't think I'll ever finish it, so here is the unfinished work for your amusement and/or enlightenment.

======== backquote-comma-dot ====

Something about ,. vs. ,@ in backquotes.


======== binding-streams ====

Which standardized stream variable may not be bound or assigned?

- *debug-io*

- *terminal-io*

- *query-io*

- None of the above

Ref: 21.1.2: "User programs may assign or bind any standardized stream
variable except *terminal-io*."

======== boa-acronym ====

For a "BOA constructor", what does BOA stand for?

- Beginning Of Array

- By Order of Arguments

- Bounded Operation Accessor

- Bidirectional Open Atom

Ref: defstruct




======== char-code ====

What value is acceptable as the return value of (char-int #\a)?

- 32

- 97

- 10

- All of the above

======== cl-package-constraints-title ====

What is the title of section 11.1.2.1.2 in the CLHS?

- Constraints on the COMMON-LISP Package for Conforming Programs

- LOOP Value Accumulation Clauses

- Examples of Suppressing Keyword Argument Checking

- None of the above

Ref: 11.1.2.1.2

======== cl-user-default-packages ====

What packages are in the COMMON-LISP-USER package use list?

- It is implementation-defined and no specific packages are specified

- It is implementation-defined but must include the COMMON-LISP
  package

- No packages

- COMMON-LISP and one of EXT, SYS, or IMPL

Ref: 11.1.2.2

======== deftype-optional-default ====

What is the default value for optional and keyword arguments in
DEFTYPE where no default is explicitly provided in the deftype lambda
list?

- T

- NIL

- *

- None of the above

Ref: deftype

======== digit-char-p ====

What function will return the integer 5 given the character #\5?

- PARSE-INTEGER

- CHAR-DIGIT-WEIGHT

- DIGIT-CHAR-P

- CHAR-CODE

Ref: digit-char-p

======== dot-dot-dot-reading ====

11:01 [tcr] There's possibly another one: "Why is
          '.. or '... not valid syntax to denote a symbol?" Answer: it's
          explicitly forbidden so READ will choke on the attempt to read print
          representations of forms where the printer introduced abbreviations
          due to *print-length*/*print-level*
11:04 [tcr]
          http://www.lispworks.com/documentation/HyperSpec/Body/02_di.htm

======== eql-is-default ====

What is the default test function for most operations? [be more
precise, maybe per 17.2.1]

- EQ

- EQL

- EQUALP

- =

Ref: 17.2.1

======== file-position-designator ====

Which of the following is not a file position designator?

- 42

- :start

- :end

- None of the above

======== format-empty-curlybrace ====

In a format string, what does "~{~}" mean?

- Nothing, it is an error to have nothing between ~{ and ~}

- Causes an infinite loop

- Uses the next argument to FORMAT as the internal format control
  string

- None of the above

Ref: 22.3.7.4

======== format-hash-arg ====

What does (format nil "~#,vD" #\8 0 0 0) return?

- "8880"

- "0008"

- "0"

- None of the above


======== get-first-element ====

Which of the following forms do NOT return the first element of LIST?

- (first list)

- (car list)

- (nth 1 list)

- None of the above

Ref: nth

======== implicit-tagbody ====

Which of the following macros does NOT have an implicit PROGN?

- DEFUN

- WHEN

- DOLIST

- None of the above

Ref: tagbody page

======== longest-function-name ====

What is the longest exported symbol name in the COMMON-LISP package?

- UPDATE-INSTANCE-FOR-REDEFINED-CLASS

- UPDATE-INSTANCE-FOR-DIFFERENT-CLASS

======== make-package-defaults ====

If you do not provide an explicit :USE argument to MAKE-PACKAGE, what
can you say about the list of packages that the newly created package
uses?

- The list consists only of the COMMON-LISP package.

- The list is implementation-dependent but always includes the
  COMMON-LISP pacakge.

- The list might be empty.

- None of the above.


======== not-a-function ====

Which of the following symbols does not name a Common Lisp function?

- PAIRLIS

- REVAPPEND

- CONJUGATE

- None of the above

Other possibilities: SCHAR, PHASE, MAKE-INSTANCES-OBSOLETE,
MAKE-LOAD-FORM-SAVING-SLOTS (from tcr)

======== not-a-string-designator ====

Which of the following is NOT a string designator?

- :foo

- #\x

- #xBA5

- None of the above

Ref: glossary for string designator, string function

======== odd-forms ====

Which form is illegal syntax? [not really syntax, but]

- (defvar *foo*)

- (aref array)

- (*)

- None of the above


======== sharpquote-let ====

13:51 <stassats`> i like (let (#'1) (+ function 2)) => 3
13:51 <pjb> (let (#'1 '2) (+ function quote))

======== zero-dimensional-arrays ====

Something about (aref thing) or (setf (aref thing) 42), and
(make-array nil :initial-element 42), etc.

Status update on Nikodemus's crowdfunded SBCL work

xach@xach.com — Mon, 10 Sep 2012 18:31:23 GMT

Any status update that starts off like this is bound to be something of a bummer:

A long overdue status update, and an apology.
I’m very sorry about my lack of communication on this project. I’m not terribly proud about all other aspects of the way I’ve handled things either, but failure to let you people know how thing stand is something I’m actively ashamed of. I apologize.
This is me trying to fix that.

You can read the whole update on indiegogo.

Sunset in Bug Light Park, South Portland, Maine

xach@xach.com — Mon, 03 Sep 2012 15:27:14 GMT