PBS Tidbit 8 – Interview with jq Maintainer Mattias Wadman

In ye olden days, iOS kept everything sandboxed in a way that apps weren't allowed to reach outside of their own data to open individual files. But with the aptly named Files app, and an API to allow a human to do the picking, apps can now open files directly on iOS. This "innovation" allows us to have a Git client on iOS and have it use a linked repo that's stored in the Files app. This means we can use any text editor we like to open the repos files for editing. In this tidbit episode of Programming By Stealth, Bart walks us through how to configure the iOS Git client Working Copy to clone a repo from GitHub, and then open the files in his favorite text editor on iOS, Textastic. Hat's off to Jill of Kent that explained to Bart and me more than a year ago that this was possible, but a fist shake to Bart for not telling me how to do it till now! You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Join our Slack at podfeet.com/slack and check out the Programming By Stealth channel under #pbs. Referral Links: Parallels Toolbox - 3 months free for you and me Learn through MacSparky Field Guides - 15% off for you and me Backblaze - One free month for me and you Setapp - One free month for me and you Eufy - $40 for me if you spend $200. Sadly nothing in it for you. PIA VPN - One month added to Paid Accounts for both of us CleanShot X - Earns me $25%, sorry nothing in it for you but my gratitude

We have a bit of a changeup for today's lesson. While Bart Busschots is in attendance for this episode, he is not be the instructor, he is a student like me. Our instructor today is the delightful Helma van der Linden and she's going to teach us about how she applied the Model View Controller pattern to our project XKPasswd. You can find Helma's fabulous tutorial shownotes at pbs.bartificer.net. Join the Conversation: [email protected] podfeet.com/slack Support the Show: Patreon Donation PayPal one-time donation Podfeet Podcasts Mugs at Zazzle Podfeet 15-Year Anniversary Shirts Referral Links: Parallels Toolbox - 3 months free for you and me Learn through MacSparky Field Guides - 15% off for you and me Backblaze - One free month for me and you Setapp - One free month for me and you Eufy - $40 for me if you spend $200. Sadly nothing in it for you. PIA VPN - One month added to Paid Accounts for both of us CleanShot X - Earns me $25%, sorry nothing in it for you but my gratitude

We're back from our summer hiatus (actually scheduled for the first time ever instead of accidentally happening!) In this week's episode, Bart takes on the task of explaining the philosophy behind why having a framework for software development is useful and even crucial as projects get bigger and more complex. We chose this topic because the XKPasswd project has already started using a framework called Model View Controller. We get the barest understanding of MVC in this explanation from Bart, and the next episode of Programming By Stealth will be the wonderful Helma van der Linden explaining the details of her implementation of MVC for the XKPasswd project. In the first episode of its kind, I won't be the only student in the class - Bart and I will be learning together. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Join the Conversation: [email protected] podfeet.com/slack Support the Show: Patreon Donation PayPal one-time donation Podfeet Podcasts Mugs at Zazzle Podfeet 15-Year Anniversary Shirts Referral Links: Parallels Toolbox - 3 months free for you and me Learn through MacSparky Field Guides - 15% off for you and me Backblaze - One free month for me and you Setapp - One free month for me and you Eufy - $40 for me if you spend $200. Sadly nothing in it for you. PIA VPN - One month added to Paid Accounts for both of us CleanShot X - Earns me $25%, sorry nothing in it for you but my gratitude

In this Tidbit version of Programming By Stealth, Bart Busschots interviews Mattias Wadman, one of the maintainers of the jq project. This was great fun as we just finished learning jq in Programming By Stealth. Read an unedited, auto-generated transcript with chapter marks: PBS_2024_08_06 You can find out more about Mattias & the various projects he is working on at the links below: Follow Mattias on Mastodon: @[email protected] Mattias’ GitHub Profile which hosts some notable jq-related projects: fq for querying binary files with the jq language: github.com/wader/fq A list of presentations about fq — github.com/… The fork of the Go version of jq that powers fq — github.com/… The language definition file for adding jq support to IDEs like VS Code: github.com/wader/jq-lsp jq implemented in jq: github.com/wader/jqjq Some notable jq commits & files mentioned during the interview: The very first commit in Haskel The switch to C jq’s main function which is written in jq — https://github.com/… A version of jq implemented in Go: github.com/itchyny/gojq A version of jq implemented in Rust by Michael Färber: github.com/01mf02/jaq Michael’s formal specification of the jq language — github.com/… The “Denotational Semantics and a Fast Interpreter for jq” academic paper by Michael

In this special tidbit installment of Programming By Stealth, Helma van der Linden joins Allison to walk through how she solved a real-world problem using jq. The problem to be solved was a need to analyze the installed applications on her Intel-based Mac before migrating to her new Apple Silicon Mac. She used a built-in Terminal command to access System Information to create a JSON file, and then used a series of jq filters to remove data she didn't need, and format what she kept into human-readable form. Helma walks us through every step of the way as she built up her jq script file to massage the data to her needs. At the end Allison explains how to take Helma's final CSV output and analyze the data in a spreadsheet using a pivot table. You can find _Helma's_ fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: PBS_2024_07_20 Join our Slack at podfeet.com/slack and look for the #pbs channel, and check out our pbs-student GitHub Organization. It's by invitation only but all you have to do is ask Allison!

In this second (and final) installment about YAML, Bart teaches us who to write multi-line strings and how not to write multi-line strings. He teaches us about String Blocks which is a bit head-bendy but allows you to write human-readable strings and also tell YAML what to do with empty lines and white space. After that slightly heavy lift, we learn about how to write much simpler-looking Sequences and Mappings than the way we learned in our introduction to YAML in PBS 168. It's really nifty how you can write them in compact, sensible forms, and even easily combine separate YAML documents into the same sequence or mapping. Finally we learn how to use the `yq` language to query JSON, CSV, and XML files using a language that uses `jq` syntax so you'll feel right at home. Read an unedited, auto-generated transcript with chapter marks: PBS_2024_07_06

In Programming By Stealth, we've completed our series on the jq language and now Bart Busschots brings us a two-part miniseries about the YAML data format. He takes us through the history of data formats we've "enjoyed" such as fixed-width text files, Comma Separated Value files, through to JSON and XML. All of them had their place in history but also had their downsides. YAML promises to be human-readable (yay) and computer-readable (also yay.) Once we're bought into how YAML is the data format of our dreams, Bart explains that there are only two kinds of data, scalar,s and collections, and that collections can be sequences or mapping and all of these data types go into a document. Luckily this is all of the jargon we'll have to learn and there are useful synonyms from other languages (e.g. sequences are really just arrays). I found this lesson enjoyable and not too hard on my little brain so I suspect you'll enjoy it as much as I did. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_06_22

It was actually bittersweet for Bart and me this week as he taught the final installment in our series of Programming By Stealth about jq. As Bart says partway through our recording, he thought this would just be a few episodes but it took 13 episodes to go through everything Bart thought was fun about this deceptively simple programming language. This final installment in the jq series covers querying nested data structures with the `recurse` command. One of the really fun parts of the episode is when he teaches us how to dramatically simplify our code, a concept that's often called syntactic sugar. We get to do `if` statements for the first time, where I wondered why he didn't let us have them earlier! I was cross with him for holding out on us with `try-catch` too because it would have made our coding so much easier. But that was the real theme of this installment – we had to learn the way everything works before learning the shortcuts. In the finale, he gives us a few of what he calls "honourable mentions" – little tidbits that came in handy at times. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_06_07 Join our Slack at podfeet.com/slack and look for the #pbs channel, and check out our pbs-student GitHub Organization. It's by invitation only but all you have to do is ask Allison!

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

In this installment of Programming By Stealth, Bart explains why jq is uniquely designed not to need variables (most of the time) and then explains how to use them in the few instances when there's no other way. It's really a fairly straightforward lesson as Bart sets up some clear examples and solves them with some simple variables. It's one of my favorite episodes because the problem is clear and the solutions are clear. It really shows off how clean jq is as a language. You can find Bart's fabulous tutorial shownotes at pbs.bartificer.net. Read an unedited, auto-generated transcript with chapter marks: CCATP_2024_05_11