Susam Pal
susam.net · Personal blog · on HN since 2011
Susam Pal is a programmer who writes about Lisp, Vim, and tiny programming languages, and has kept his website for over two decades.
What HN saysHN links his Lisp-in-Vim guide, which a commenter says helped them start learning Lisp, and his small drawing languages.
102HN people shared it
46linked it in comments
403stories submitted
8.4Kstory points
4 months agolast shared
2011people per year2026
Most-shared posts
- 1FXYT: A tiny, stack-based, postfix canvas colouring language with 36 commands7 people · 57 points · first shared 2023 · 7 comments on HN
- 2CFR[]: Extremely minimal drawing language with 5 commands: C, F, R, [, and ]7 people · 3 points · first shared 2023 · 1 comments on HN
- 3Lisp Programming with Vim (2019)5 people · 115 points · first shared 2024 · 17 comments on HN
- 4Lisp in Vim (2019)5 people · 48 points · first shared 2022 · 5 comments on HN
- 5Three Inverse Laws of AI5 people · 33 points · first shared 2026 · 1 comments on HN
- 6I Will Not Add Query Strings to Your URLs5 people · 6 points · first shared 2026 · discussion on HN
- 7Sinkholed4 people · 620 points · first shared 2019 · 130 comments on HN
- 8Lisp Programming in Vim with Slimv or Vlime4 people · 93 points · first shared 2019 · 42 comments on HN
- 9From XON/XOFF to Forward Incremental Search4 people · 34 points · first shared 2022 · 2 comments on HN
- 10A Kid Who Could Read My Mind (2009)4 people · 11 points · first shared 2019 · discussion on HN
- 11Show HN: CFRS[]: Minimal drawing language with 6 commands: C, F, R, S, [, ]4 people · 9 points · first shared 2023 · 1 comments on HN
- 12Writing First, Tooling Second4 people · 5 points · first shared 2026 · discussion on HN
- 13Guess my RGB3 people · 618 points · first shared 2024 · 144 comments on HN
- 14Prime Number Grid3 people · 296 points · first shared 2025 · 96 comments on HN
- 15Solving Fizz Buzz with Cosines3 people · 218 points · first shared 2025 · 65 comments on HN
What HN people wrote when they linked it
yori · 2020-02-08
Here's a good one: https://susam.in/
Stumbled on this when his domain was hijacked accidentally due to an anti-botnet operation and his post about it came on HN (check the "Sinkholed" post). Since then I've subscribed to his blog, read the older posts and enjoyed the newer posts too.
He mostly posts about technology and mathematics. The reason why I got hooked to this blog is that they are mostly about offbeat topics that I wouldn't normally come across on my own. So there is something new to learn from every post. And they are very well written with great attention to detail.
susam · 2019-08-26
If you like writing Python code, I recommend https://github.com/sunainapai/makesite (makesite.py). As the README says, it is a simple, lightweight, and magic-free static blog generator. The entire static blog generator code is in a single file named makesite.py.
Add your content to the `content` directory. Then run `python3 makesite.py` to generate the static blog. It writes the generated blog to the `_site` directory. Finally copy this directory to wherever you want to serve your blog from, e.g., GitHub repo with GitHub pages enabled, virtual private server, cloud storage, etc.
It works pretty well out of the box and it is highly customizable too because doing so involves just modifying the existing Python code or writing your own Python code.
Disclaimer: This project has been written by my wife. I use it myself to render my static blog at https://susam.in/.
pwagland · 2025-04-10
Given that http://susam.net:8000 has stopped responding, I suspect that there will be a lot more beeps today.
ngcc_hk · 2024-04-22
Vim plus sbcl has been ok. Follow this I am happy since
https://susam.net/lisp-in-vim.html
Not 2nd class and I can use it mostly on mac; linux and windows (linux side)are ok. All good.
ryan-duve · 2024-03-01
It's been a week so I can't edit my other response to this, but yes, Slimv was what I was missing. I read your second link and followed the instructions and am now able to actually learn this language. Thank you for sharing.
For anyone else that knows Vim but can't seem to get a good CL environment going, read https://susam.net/lisp-in-vim.html
Jach · 2022-09-05
Join me vim brother and don't settle for forcing yourself to use emacs while developing in CL when you don't have to! You even have two vim options! https://github.com/kovisoft/slimv and https://github.com/vlime/vlime with a great comparison of the two: https://susam.net/blog/lisp-in-vim.html
tiffanyh · 2022-01-09
Speaking of ‘simplicity’, this blog has a fantastic design. The CSS is only ~30 lines and is largely just applying spacing/padding.
No JS, no custom font, etc.
https://susam.net/css/main.css
ffpip · 2021-05-19
Interesting. I couldn't find a blog titled "Infosys, TCS, or Wipro?" on this page - https://susam.in/
However, googling it gave me this - https://susam.in/blog/infosys-tcs-or-wipro/
carloswilson · 2020-03-01
While this product of additive inverses property does follow from the field axioms, there is a short discussion in the blog comments at https://susam.in/blog/product-of-negatives/comments/ which shows that this property holds true for all rings too.
So it is not just numbers for which this property holds true but for all elements of fields and rings too. Quite simply, (-a)(-b) = (a)(b) in all rings where (-a) and (-b) are the additive inverses of a and b respectively.
verdverm · 2026-06-25
yes, because it humanizes software
https://susam.net/inverse-laws-of-robotics.html
Ai is highly non-deterministic by design, it's a core feature that gives it the capabilities and drawbacks. Don't expect it to be accurate, stay HIL my friends
dang · 2026-05-09
Since the original source hadn't had a discussion on HN yet, I've put that link (https://chrismorgan.info/no-query-strings) at the top and moved the response link (https://susam.net/no-query-strings.html) to the toptext.
Both are good but it seems fair to give priority to the original!
aragilar · 2026-03-11
For those of us in today's 10000, Ctrl-U is the default readline shortcut for unix-line-discard (see https://www.gnu.org/software/bash/manual/html_node/Commands-For-Killin… and https://susam.net/unix-line-discard.html).
geospeck · 2026-03-10
I also found this blog post useful for using Vim with Common Lisp
https://susam.net/lisp-in-vim.html
ff00 · 2026-01-15
Found out about finding timing of http requests
https://susam.net/timing-with-curl.html
nottwo · 2025-09-22
This is fun!
I was going to try to draw a circle but was missing sin/sqrt. Then I thought of using a lookup table but got stumped.
Do you have any pointers for drawing a circle?
I'm looking at demo #4 (https://susam.net/fxyt.html#XYpTN1srN255pTN1sqD) to see where the circular shapes are coming from.
Have you seen Forth Haiku? https://forthsalon.appspot.com/
onirom · 2025-09-22
doesn't need to be accurate, could do something like this (distance + treshold) :
https://susam.net/fxyt.html#XN128dXN128dpYN128dYN128dpsN4096lN255pC
smaller with dup :
https://susam.net/fxyt.html#XN128dDpYN128dDpsN4096lN255pC
circles pattern : https://susam.net/fxyt.html#XDpYDpsN8qN3riN255pC
PS: fun tool !
AmazingTurtle · 2025-08-19
https://susam.net/primegrid.html#1-200-330
zoom out, then play around with cols +/-1 and observe the pattern change. I observe the pattern from -7 to +5; same on #1-200-420
genezeta · 2025-08-19
There's this https://susam.net/pages.html for your convenience. (Also this https://susam.net/links.html maybe a bit more organised.)
maxwellito · 2025-06-27
Good job! That’s really good! Oh damn I didn’t realised it was you!
Dear HN community, susam built the GuessMyRGB game which was a huge inspiration for this game. Please take the time to play it!!
https://susam.net/myrgb.html
sodimel · 2025-01-20
That's a nice little language!
I managed to create a very simple flower-like pattern (here: https://susam.net/cfrs.html#B6FRSF4E2RB2FRCE6 ) just by trial and error after seing one or two examples.
wonger_ · 2025-01-20
I enjoyed spending a couple hours with this toy. Constraints lead to creativity, yada yada. Here's the interactive page: https://susam.net/cfrs.html#0
Bonus challenge: try drawing circles in under 64 bytes
8BitArmour · 2024-03-13
This guy's article on infosys is good too: https://susam.net/infosys-tcs-or-wipro.html
TJSomething · 2023-12-22
I got this fun little ripple effect by implementing Newton's method to do a square root.
https://susam.net/fxyt.html#MXN127dDpYN127dDpsN5qDN2qNN6bRRSDRDRSqsN2q…
mepian · 2023-11-07
There is Alive for Visual Studio Code: https://lispcookbook.github.io/cl-cookbook/vscode-alive.html
If you prefer Vim, there are two major options: https://susam.net/blog/lisp-in-vim.html
gus_massa · 2023-10-28
In Firefox on Android, I can use the demo if I use the link in github https://susam.net/cfrs.html, but I don't see the graphics if I use the examples like https://susam.net/cfrs.html#1 I tried looking for difference in the domain like www, but I can't find any.
merelysounds · 2023-10-22
furyofantares · 2023-10-22
To get to the bottom left: [RRR][[[[[[F]F]F]F]F]F]F[RRR][[[[[[F]F]F]F]F]F]FF
https://susam.net/cfr.html#BR3EB6FEFEFEFEFEFEFBR3EB6FEFEFEFEFEFEF2
Prepend a C to get there without drawing lines on the way. Suffix with [RRRRRR]C to rotate upwards and get a visible color again.
Whenever I'm lost I paste [[[[CFCF]]]] at the end to find my cursor.
zerojames · 2023-10-21
I added some letters to a demo and made https://susam.net/cfr.html#B15FRCFE7R2F4C11BR3E6C2E3. Thank you for making this! I don't know how it works but it is fun!
neontomo · 2023-10-21
I played around with it but I don't have a clue what I'm doing. Managed to make this pretty geometric shape based on one of your examples though:
https://susam.net/cfr.html#B15F15CRE6RF2BR2FE6CE3
I wonder what an AI could design with instructions for how to use this.
dividuum · 2022-12-05
This is discussed at length in the blog post itself: https://susam.net/blog/self-printing-machine-code.html#quine-conundrum… A non-cheating quine is provided as well.