Programming By Stealth

PBS 166 of X — jq: Processing Arrays & Dictionaries sans Explosion

Programming By Stealth

Show Notes

In this penultimate jq episode of Programming By Stealth, Bart introduces us to three new ways to process arrays and dictionaries without exploding them first. I know that sounds crazy – we've always exploded our arrays first. He teaches us how to use the `reduce` operator which lets us take an entire array or dictionary and reduce it down to one thing. The `map` function lets us process every element in an array (or or values in a dictionary) and return a new array. Finally, `map_values` lets us apply a function against all of the values in a dictionary (or an array).

It was a bitter sweet ending to the primary series on `jq` for Bart, but next time he'll do the epilogue where he'll introduce us to some rarely needed but still very useful things you can do with jq.

You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net.

Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_05_25

More from Programming By Stealth

Oct 11, 2026

We dust off our memory from where we left off learning about Jekyll back in PBS 181 in June of last year. After some housekeeping, Bart takes us through the challenge solution from PBS 181, and then teaches us how to add metadata to our static sites. After the new material, he sets up where we're going next in learning how to organize our content with Jekyll taxonomies. He even explains what the weird term "information architecture" means in this context.

Sep 26, 2026

In this final episode of Tidbit 19, Bart walks us through the very few libraries he used for the final design of his Linkifier CLI App. His choices on tooling to build nice terminal commands and provide color in the terminal (like red for error messages) were based on simplicity, the fewest dependencies, and active support. It was a very fun episode to record as he wrapped the entire story up in a bow.

Aug 30, 2026

We're back with Part B of Tidbit 19, where Bart walks us through the architecture of his Linkifier module. He starts with the three data modeling classes that he's been using for decades, but explains how hard it is today to extract article headlines. He walks through how he developed an extraction logic but had to do it per domain. That sounds crazy but he uses surprisingly few sites for his articles for Security Bits and Let's Talk Apple.

Aug 11, 2026

In Part A of Tidbit 19, Bart explains the problem he needed to solve, which was bringing a script he's written up into the modern age as a JavaScript command-line interface app that can help navigate the AI landscape. As always, his explanation is geared towards teaching us the fundamentals with his problem as the example.

Jun 28, 2026

One of the things that helps your posts get traction is if you have a nice, pretty card that displays when you post the URL on social media. Plain blue links just don't get clicked. With WordPress and other dynamic Content Management Systems (CMSs), you can get plugins to create the pretty cards. But with Jekyll (and Hugo and other Static Site Generators), you need to build the capability into your theme. It's not hard, you just need to know what metadata to build, and of course, Bart is here to teach it to us.

See all episodes →