Computer Science on stau.space

Language Semiring

sona@stau.space (Sona Tau Estrada Rivera) — Sun, 31 May 2026 20:28:46 -0400

I actually wrote this blog post a couple months ago but only decided to shape it up for posting today: june 18th.

In my computation theory class, after defining a regular expression, we also defined operations $\cdot$ and $\cup$. These operations would take a set of words in a regular language and construct yet another set of words. Interestingly, there were some special sets that make this look like a ring:

The empty set $\emptyset$ which has the following properties:
- It is an identity element for the $\cup$ operation: $\emptyset \cup A = A \cup \emptyset = A$.
- It is an annihilator element for the $\cdot$ operation: $\emptyset \cdot A = A \cdot \emptyset = \emptyset$.
The set with one element $\{\epsilon\}$ which is a language that only identifies the empty string has the following properties:
- It is an identity element for the $\cdot$ operation: $\{ \epsilon \} \cdot A = A \cdot \{ \epsilon \} = A$.

This makes it almost a ring with:

AOC day 1

sona@stau.space (Sona Tau Estrada Rivera) — Thu, 05 Dec 2024 13:55:24 -0400

wan wan.
zz pana pi (toki tawa lipu) li nasin lipu tu e wan.
zz pana pi (toki tawa lipu) li suli.
zz poka li sin pana ala li nanpa sewi e luka.
zz ale li sin pana.

 ⍉ pana
⟨ ⟨ 4 3 5 3 9 3 ⟩ ⟨ 3 4 2 1 3 3 ⟩ ⟩
 ∧˘⍉ pana
⟨ ⟨ 3 3 3 4 5 9 ⟩ ⟨ 1 2 3 3 3 4 ⟩ ⟩
 |-˝∧˘⍉ pana
⟨ 2 1 0 0 1 5 ⟩
 +´|-˝∧˘⍉ pana
9

AOC day 2

sona@stau.space (Sona Tau Estrada Rivera) — Mon, 02 Dec 2024 00:00:00 -0400

Zig CTFP

sona@stau.space (Sona Tau Estrada Rivera) — Wed, 07 Aug 2024 11:38:20 -0400

Let this blog post be living proof that Zig is in fact also a functional programming language.

C++ Prelude

sona@stau.space (Sona Tau Estrada Rivera) — Mon, 08 Jan 2024 18:04:59 -0400

Modern C++ makes me sad when I look at it. So this is my attempt to change several of the defaults we use to code in C++. Additionally, several features that are missing in the language (but enabled through obscure compiler macros and directives) are enabled.