[HN Gopher] Lisp Koans
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Lisp Koans
Author : phoe-krk
Score : 129 points
Date : 2020-11-28 10:43 UTC (12 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| vilhelm_s wrote:
| I thought this would be http://hackersdictionary.com/html/Some-
| AI-Koans.html .
| phoe-krk wrote:
| _A novice was trying to fix a broken Lisp machine by turning
| the power off and on._
|
| _Knight, seeing what the student was doing, spoke sternly:
| "You cannot fix a machine by just power-cycling it with no
| understanding of what is going wrong."_
|
| _Knight turned the machine off and on._
|
| _The machine worked._
|
| ---------------
|
| Always beautiful to read those.
| phoe-krk wrote:
| If you've seen the Lisp Koans in the past, you might want to
| revisit them someday. Around half a year ago I've rewritten[0]
| the original set of koans, fixed multiple correctness issues,
| added some content, and cleaned up the test framework; they now
| look much better than the original version.
|
| [0] https://github.com/google/lisp-koans/pull/111
| cnasc wrote:
| Thanks! I've got your book next to my desk on the top of the
| pile of things to read next
| phoe-krk wrote:
| Thanks! Hope that it serves you well.
| zdragnar wrote:
| Thank you!
| phoe-krk wrote:
| My pleasure, hope they serve you well.
| owyn wrote:
| Cool, I started doing these a couple of years ago, nice to
| have an updated version. I haven't done lisp in a long time
| but I'm trying to get back into CL.
|
| One question: using SBCL I can run the script with sbcl
| --script contemplate.lisp but how do I load the koans into
| the repl in a way that has all the helper/test functions
| available? If I just (load "test-framework.lisp") or do
| sbcl --load contemplate.lisp, I get a bunch of warnings and
| things like (assert-equal t t) throw "undefined function".
| It's mentioned in the original PR that this "should" be
| possible now but I didn't see it in the README.
|
| One thing I'm very not familiar with yet is the
| quicklisp/abcl and packaging system so this is probably
| very obvious. Thanks!
| phoe-krk wrote:
| Hmmm. Koans in the original form _will_ warn because they
| are incomplete, so loading them altogether is going to
| not work very well. I don 't think that the current
| version of koans is very well-suited for interactive
| development; please feel free to open an issue for that
| and perhaps it will get done someday.
| owyn wrote:
| Okay cool, I can just eval the actual code separately
| from the koan test framework for now, it's fine. Sounds
| like an interesting problem for the reader for sure. :)
|
| _edited with suggestion to call use-package_ I 'm not
| very familiar with the lisp packaging stuff yet.
|
| Here's what I was trying to do: * (load
| "test-framework.lisp") T * (use-package
| :lisp-koans.test) T * (assert-equal t t)
| debugger invoked on a UNBOUND-VARIABLE in thread
| #<THREAD "main thread" RUNNING {1001570143}>: The
| variable LISP-KOANS.TEST::*KOAN-ASSERT-LIST* is unbound.
|
| Aha it looks like it's part of the code that is testing
| for blanks in the original form. (if
| (form-contains-blanks-p form) (push :incomplete
| *koan-assert-list*)
|
| That seems like it's fixable, maybe I will open a bug for
| that. I don't think it expects to run outside of the run-
| koan function. That's fine, I'll stop there until I know
| enough to fix it haha.
|
| Also thanks for answering my noob questions! I just
| realized you also wrote the Common Lisp Condition System
| which is on my TO-READ list (after I do about 100 hours
| of lisp refresher stuff lol).
| phoe-krk wrote:
| Oh! I see now! You're not using the LISP-KOANS.TEST
| package.
|
| (use-package :lisp-koans.test) and you should be good to
| go.
| phoe-krk wrote:
| For that, you should be able to load the test framework
| and the koan helper file separately. Then try to evaluate
| individual koans in emacs/slime - it should work.
| phoe-krk wrote:
| Yes, none of this expects to be run outside of the
| standard koan run. Sorry about this; please open an issue
| and eventually I'll patch this code to be runnable
| outside of the koans file.
| pmoriarty wrote:
| Are these available for Emacs Lisp?
| phoe-krk wrote:
| Seems like https://github.com/jtmoulia/elisp-koans is
| available, but it was forked before my changes and therefore
| does not seem to include them.
|
| Might be worth to update them if anyone finds the time for
| that!
| jtmoulia wrote:
| Awesome to see such a comprehensive update to the lisp koans.
| much thanks!
|
| Like you said, elisp-koans was forked from lisp-koans awhile
| back. Bringing over the additional coverage you added will be
| a great improvement!
|
| I love the addition of the `koans-solved` directory. I was
| using a separate branch, but that was a pain to keep in sync
| with master. Will definitely bring that over :)
| submeta wrote:
| Just started learning Emacs Lisp. Common Lisp is on my todo list.
| Glancing through these tasks, I realize I have a lot to learn
| before I can call myself proficient. But I am very eager. Started
| reading Guy Steele and Touretzky. Love the concepts, the
| simplicity, homoiconicity, Lisp macros, and the fact that it is
| time tested.
|
| ## Edit
|
| Years ago when I was confronted with a new technology that caught
| my interest, I'd ask myself: Is it in use? Is it wide-spread? Is
| it used by companies in commercial situations?
|
| My questions have changed. Now I tend to apply questions like:
| Does the hacker in me get excited? Does this technology help me
| solve problems? Does it make my life easier?
| capableweb wrote:
| About the questions that has changed over time. I see them as
| questions that depend on the context rather than experience
| and/or time.
|
| If you're trying to build something many people should be able
| to build upon, you as a developer should be easily replaceable
| and you want to have a high hiring pool with mid-level
| developers (like how the typical startup thinks), then your
| first questions are more appropriate.
|
| But if you're looking to build something for fun, to scratch
| your own itch or trying to do something more innovative than a
| CRUD app, then perhaps your latter questions are more
| appropriate.
| jtmoulia wrote:
| I ported lisp-koans to elisp https://github.com/jtmoulia/elisp-
| koans
|
| It's still rough and doesn't include @phoe-krk's latest changes
| (forked 1.5yrs ago), but I found it super useful for learning
| lisp.
| abhinav22 wrote:
| Try this guide - it's quite a good and concise introduction and
| will get you coding quickly. It can be read alongside a
| textbook:
|
| https://github.com/ashok-khanna/common-lisp-by-example
|
| (Disclaimer: I'm the compiler of this guide)
| Kelamir wrote:
| I love the guide. Thank you very much, abhinav22.
| abhinav22 wrote:
| You are most welcome Kelamir :)
| monroewalker wrote:
| Awesome guide :). I've been meaning to learn the basics of
| LISP since trying out Emacs and this was finally an easy
| enough introduction to it that I've read a fair amount.
| Thanks for this!
| abhinav22 wrote:
| Your welcome :) I was (am) in the exact same shoes as you,
| so I wrote notes along the way , hence us beginners "get"
| it ;)
|
| Good luck and I hope to see you as a pro lisp programmer in
| a few months!
| dunefox wrote:
| Looks good, thanks. Will you include more topics that are
| missing now?
| abhinav22 wrote:
| Nah, it was a conscious choice to limit the amount of
| material in the guide as not to overwhelm the beginner.
|
| The various textbooks on lisp are great and this wasn't
| aimed to replace them, but just guide the reader through
| the initial phase where they may be overwhelmed.
| Zhyl wrote:
| I really like the koans format of language learning. I find they
| pique and sustain my interest more than rote tutorials or trying
| to glean purpose, feel and function of languages.
|
| It feels much more like a puzzle, the hints can be more cryptic
| and requires me to be more bought in than an introductory podcast
| or an online set of lessons.
|
| I'd love to see this format applied to other topics and fields,
| although none will likely lend themselves to the format as
| natively as programming languages will.
| markc wrote:
| Clojure Koans: http://www.clojurekoans.com/
| dimitar wrote:
| These are pretty easy compared to 4clojure, so they are perhaps
| the best for beginners.
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(page generated 2020-11-28 23:01 UTC)