Hacker News: co_dh

New comment by co_dh in "If AI writes your code, why use Python?"

co_dh — Tue, 12 May 2026 14:57:39 +0000

I used Claude that created a terminal based table viewer from rust first, to lean , and finally to Haskell. https://github.com/co-dh/tv-hask/tree/main

I give up rust because it’s not functional enough. There aren’t many things Claude can prove about a table viewer, and Haskell fits very well, and have enough libraries. Claude is pretty good at Haskell. I barely write Haskell before but I do know monad.

New comment by co_dh in "State of Terminal Emulators in 2025: The Errant Champions"

co_dh — Tue, 04 Nov 2025 11:34:28 +0000

I have to warning everyone: Windows terminal with true color , possibly with tmux, is very slow. There is a half second delay from key press to response. I am in a vdi. Your miles varies.

New comment by co_dh in "Protobuffers Are Wrong (2018)"

co_dh — Sat, 06 Sep 2025 13:41:00 +0000

But why do you need serialization? Because the data structure on disk is not the same as in memory. Arthur Whitney's k/q/kdb+ solved this problem by making them the same. An array has the same format in memory and on disk, so there is no serialization, and even better, you can mmap files into memory, so you don't need cache!

He also removed the capability to define a structure, and force you to use dictionary(structure) of array, instead of array of structure.

New comment by co_dh in "ZSA Voyager: Low profile split keyboard"

co_dh — Tue, 05 Sep 2023 15:25:02 +0000

At this price(360), I may want to try glove80.

New comment by co_dh in "How to check if two SQL tables are the same"

co_dh — Fri, 28 Jul 2023 23:29:19 +0000

In kdb+/q, it is only 1 character ~

New comment by co_dh in "Ask HN: If you were suddenly Financially free, what would you do next?"

co_dh — Sat, 27 May 2023 12:46:10 +0000

I wake up.

New comment by co_dh in "Can Rust Beat JavaScript in 2023?"

co_dh — Fri, 21 Apr 2023 16:15:33 +0000

Any language with repl can have it . Python for example

New comment by co_dh in "916 Days of Emacs"

co_dh — Fri, 14 Apr 2023 21:59:05 +0000

A single threaded OS. I remember that sometimes I launched a slow process in emacs, and then can do nothing but wait.

New comment by co_dh in "Programming-language popularity by GitHub pull requests"

co_dh — Fri, 07 Apr 2023 19:18:59 +0000

What is DDD?

New comment by co_dh in "K: We need to talk about group"

co_dh — Sat, 01 Apr 2023 18:39:55 +0000

Q/kdb, it is practical, and you can find a good pay job with it.

New comment by co_dh in "K: We need to talk about group"

co_dh — Sat, 01 Apr 2023 18:38:47 +0000

Group is actually like inverse a mapping. Given an array A which map index to value, group A map value to index. A common idiom is: desc count each group A , which list most frequent element first

New comment by co_dh in "K: We need to talk about group"

co_dh — Sat, 01 Apr 2023 18:35:29 +0000

https://code.kx.com/q/ref/

New comment by co_dh in "K: We need to talk about group"

co_dh — Sat, 01 Apr 2023 18:34:24 +0000

In q/kdb. iPhone replaced q with a. Sorry

New comment by co_dh in "K: We need to talk about group"

co_dh — Fri, 31 Mar 2023 21:07:57 +0000

I am happily programming in a for 6 years now, and will not give it up

New comment by co_dh in "The Janet Language"

co_dh — Sat, 18 Feb 2023 14:36:07 +0000

Me too

New comment by co_dh in "Ask HN: I'm 40 and feel my mental ability declining. Programming seems harder."

co_dh — Tue, 10 Jan 2023 15:03:31 +0000

48 , and feel smarter than before

New comment by co_dh in "Ask HN: I'm 40 and feel my mental ability declining. Programming seems harder."

co_dh — Tue, 10 Jan 2023 15:02:06 +0000

Sleep, exercise, chess

New comment by co_dh in "ArriveCan’s $54M price tag ‘outrageous,’ tech leaders say"

co_dh — Fri, 07 Oct 2022 14:36:03 +0000

This is how my money get wasted.

New comment by co_dh in "Senior engineers are living in the future"

co_dh — Tue, 13 Sep 2022 17:15:37 +0000

I put semicolons at the beginning of line.

New comment by co_dh in "Why do arrays start at 0?"

co_dh — Wed, 24 Aug 2022 18:08:05 +0000

Human makes a lot of inconsistent thing: We usually think the 1st floor, and the basement as 1st underground floor ( -1), but the floor jumps from 1 to -1!

Also, the time jump from 11AM to 12PM to 1PM! So I think more human friendly sometimes means more confusing.