Abstract Nonsense

A place for musings, observations, design notes, quick tips...
thought gists, if you like.

18.02.2025 Surely you're `jq`ing

Today I read through the jq manual cover-to-cover. For those unaware, jq is a popular CLI tool to query and manipulate JSON. It’s also a Turing-complete mini-language with nice functional semantics that fits well into the ethos of composable CLI tools.

It was an exemplar of well-written technical documentation. Concise, well-written, littered with examples, and linking to an interactive playground to test-and-learn.

Some learnings:

It’s surprisingly functional! You can implement recursive functions and use higher-order functions! For example, here’s factorial in jq:

jq '[.,1]|until(.[0] < 1; [.[0] - 1, .[1] * .[0]])|.[1]'

It supports string interpolation - this is really nice if you’re piping stuff from JSON into a string. Coupled with format strings this becomes frictionless:

$ echo '{"search":"hello; world"}' | jq -r '@uri "https://www.google.com/search?q=\(.search)"'
# https://www.google.com/search?q=hello%3B%20world

You can define functions that accept functions¹, and control structures that allow labelling.

echo '[[1,2],[10,20]]' | jq -r 'def addvalue(f): . + [f]; map(addvalue(.[0]))'
[[1,2,1], [10,20,10]]

You can traverse complex data structures with first-class pathing support. And you can easily modify nested structures to extend objects.
For the category theorists/polyglots, there’s a denotational semantics paper written about jq.
Bonus: You can build a Brainfuck interpreter in jq; and you can build a jq interpreter in jq - how’s that for bootstrapping!

Side note: This is one of my goals for 2025 - read through documentation end-to-end to develop mastery over tools. I’m trying to prioritise selectively depth over breadth.

The line between “functions” and “filters” is a little blurry to me. ↩︎

15.02.2025 Shellshocked? Brace yourselves!

I just discovered that to capture multiple lines of stdout from a shell script and redirect them to a file, you can simply wrap them in braces!

For example, my “Create a blog post via a GitHub Action triggered on an Issue creation” workflow uses this snippet:

{
  echo "---"
  jq 'del(.content)' "parsed_issue.json" | yq -P
  echo "---"
  echo ''
  
  # Inline "content" key for the body
  jq -r '.content' "parsed_issue.json"
} > content/micro-blog/"$FILENAME"

27.01.2025 Typography in Parasite

This is awesome! Typographic Hangul from the title scene of Parasite

22.01.2025 Developer Ergonomics

“I wonder how much it is insightful to watch someone doing a workflow and to note when discomfort kicks in. That’s a really insightful thing to realize what matters from bitter experience, right? … Experience tells you when to worry about something and when not to worry about it” - Ben Sparks

That is - the rising discomfort of a programmer when employing a new tool, framework, or library is a good window into the ergonomics of how one uses your tool, framework, or library. Source: How I animate 3Blue1Brown | A Manim demo with Ben Sparks. The whole video is worth checking out! It’s a masterclass on how to construct a programatic-animation library and demonstrate how to work within it.

When I get a chance, I’d love to unpack the source code for how sprite-to-sprite transforms (part of 3B1B’s signature look) and the vectorised rendering engine are implemented with OpenGL.

18.06.2024 Audiolising SwiftUI Graphs

This demonstration of an auditory representation of a (visual) graph in Swift Charts is wild: Vectorized and function plots in Swift Charts at WWDC24.

28.05.2023 Week 22

I noted that there’s a difference between Anomaly detection and Outlier detection.
Word of the week ~ enjambement

enjambement: (in verse) the continuation of a sentence without a pause beyond the end of a line, couplet, or stanza.
As an aside, I find Rust as a language fiendishly complex at a first glance, and I’m amazed by people who find it so straightforward. Having said that, I’d much rather have lived in a universe where Rust was the first ’low-level’ language I learnt instead of C.

21.05.2023 Week 21

Discovered the concept of similarity graphs through a talk on Uniform Manifold Approximation and Projection (UMAP) for Dimension Reduction at SciPy 2018.
Word of the week ~ grimoire, from French, an alteration of “grammaire” (grammar)

grimoire: a book of magic spells and invocations.
Also, in the world of books: The Cossacks by Leo Tolstoy.