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David Foster

@davidfstr@mastodon.world

mastodon 4.7.3

Software sculptor. Writer. Teacher. Inquiring mind. Bringing world-class computer science education to K-12 schools, teachers, and students at https://techsmart.codes

70 Followers

84 Following

22 Posts

Joined November 18, 2022

Website:

https://dafoster.net/

GitHub:

https://github.com/davidfstr/

David Foster @davidfstr@mastodon.world

· 2mo ago

Replying to

@drwhax@infosec.exchange I've been very concerned about the emergence of Mythos-class AI that can weaponize vulns. I'm personally responding by adding formal memory safety proof coverage to critical libraries in C (notably: OpenSSL). Testing - which can identify many but not all bugs - I no longer consider sufficient. Instead we need formal verification to prove the *absence* of bugs/vulns. #aicoding #security

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David Foster @davidfstr@mastodon.world

· 5mo ago

RE: @eniko@mastodon.gamedev.place

Even with today's most advanced AI coding tools/models I consistently find their output - although functional - to lack in readability/ maintainability/ elegance. I always have to revise AI code to meet my standards. The current trend of some prominent folks having no human review at all for AI code I think is a shame and sometimes even harmful. Consider: Security bugs in AI drafted/unreviewed code. #aicoding

mastodon.gamedev.place

Eniko Fox: "Imagine being a coder but thinking there's no art…" - Gamedev Mastodon

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David Foster @davidfstr@mastodon.world

· 5mo ago

gvc (git-visual-compare) is a new visual git diff tool that I'm releasing today! Try it out at: https://dafoster.net/projects/gvc/ #coding #programming #diff #git

I've been using the diff mode of the venerable yet unmaintained GitX tool for a decade. But now I need my diffs to support dark mode, to avoid waking the baby at night. Astonishingly, existing GUI diff tools only support diffing *individual* commits, not ranges . So I finally bit the bullet and wrote my own. Enjoy!

gvc (Git Visual Compare) | A Visual Diff Viewer for macOS | DaFoster

A lightweight macOS GUI for viewing git diff output. The ease of a visual diff viewer, the power of a command-line diffing tool.

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David Foster @davidfstr@mastodon.world

· 5mo ago

Oops, I wrote a database. I discuss some of challenges I faced getting full ACID guarantees working in my latest post: https://dafoster.net/articles/2026/02/23/oops-i-wrote-a-database/ #databases #warstories #programming

Oops, I wrote a database | DaFoster

Oops, I wrote a database | DaFoster

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David Foster @davidfstr@mastodon.world

· 5mo ago

Replying to

@troed@swecyb.com You’ll notice that I still put myself as the primary Author - and therefore the one responsible - even when using AI assistance to draft code. I always review the code myself if I plan to share it. If I did no reviews - pure vibing - then responsibility *would* be harder to pin down.

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David Foster @davidfstr@mastodon.world

· 5mo ago

I wrote up how I've been attributing usage of AI models & coding agent harnesses when drafting code commits: https://dafoster.net/articles/2026/04/17/ai-attribution-in-git/ #aicoding #git

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David Foster @davidfstr@mastodon.world

· 28mo ago

Replying to

@geoff@front-end.social When I was a boy tinkering around with making my own website I used a resource called HTML Goodies (now dead) which assumed no prior knowledge. I applaud the creation of similar resources for the current generation, when #WebDevelopment has gotten so complex by default.

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David Foster @davidfstr@mastodon.world

· 29mo ago

Replying to

@kcase Ideal collaboration flow allows a diagram to be reachable from a URL, embedded in our online wiki. URL allows immediate viewing (for everyone) & editing (for those with an edit license). Ability to leave comments at specific points in diagram, with email notifications, as the primary mode of collaboration. Rare to literally have multiple people editing same diagram simultaneously. No need to worry about edit conflicts, or working with a stale version of a file.

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David Foster @davidfstr@mastodon.world

· 29mo ago

Replying to

@kcase Our engineering team all uses Macs, so no trouble editing. It’s just cumbersome to have to get a link to Dropbox (which we are deprecating internally) or to GitHub, download a file, edit, screenshot something to insert elsewhere, and reupload a file.

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David Foster @davidfstr@mastodon.world

· 29mo ago

Replying to

@kcase Our product manager is not using a Mac, so an omnigraffle:// URL probably wouldn’t work. — On engineering laptops where OmniGraffle is setup in advance (not always the case), presumably such a link could work, especially if it could push/pull directly from Dropbox, Google Drive, and GitHub (which are all the hosting locations we use).

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David Foster @davidfstr@mastodon.world

· 29mo ago

Replying to

@kcase I’m fine manually updating an image in the Google Docs wiki page when the diagram changes. No diagram provider (TLDraw, Figma FigJam, Lucidchart) currently has a Google Doc integration that works smoothly enough to actually use.

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David Foster @davidfstr@mastodon.world

· 29mo ago

@kcase Glad to hear OmniGraffle is still under active development. Still my favorite tool for *high-fidelity* diagrams. Alas I mostly cannot use at work because there’s no online *collaborative* interface that allows other team members to edit diagrams AFAIK.

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David Foster @davidfstr@mastodon.world

· 5mo ago

Replying to

@davidism Hey I think the security policy that Pallets has documented is pretty clear. 👍 I'll probably crib some of it when I get around to writing out my projects' security policies. https://palletsprojects.com/security

palletsprojects.com

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David Foster @davidfstr@mastodon.world

· 5mo ago

GitHub Copilot Agent (GCA) is moving from per-request/interaction billing to token-usage based. Shucks. I've been enjoying the ability to give 1 well-specified request to GCA and have it churn for 15 minutes, while only charging me 1 "premium request". https://github.blog/news-insights/company-news/github-copilot-is-moving-to-usage-based-billing/ #aicoding

The GitHub Blog

GitHub Copilot is moving to usage-based billing

Starting June 1, your Copilot usage will consume GitHub AI Credits.

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David Foster @davidfstr@mastodon.world

· 5mo ago

4 GB of space remaining. Restart computer. 22 GB of space remaining. -- Wild to see such a large fluctuation. I still remember when my total drive capacity was 0.5 GB (500 MB)...

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David Foster @davidfstr@mastodon.world

· 5mo ago

I actually like Claude Code’s 5-hour session limits on usage. It enforces that I take a break occasionally and trains me to prompt more cost-efficiently, which will be useful whenever token prices stop being subsidized. #aicoding

Mastodon

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David Foster @davidfstr@mastodon.world

· 5mo ago

I created a Revise Skill (for Claude Code, Codex, VS Code, etc) that helps AI coding agents write code the way I want, optimized for readability & maintainability: https://dafoster.net/projects/revise-skill/ #aicoding #refactoring

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David Foster @davidfstr@mastodon.world

· 5mo ago

If you're spending more than $100/month/engineer on AI tokens, you're doing it wrong. Use a subscription. I currently subscribe to Claude Pro ($20/mo) and GitHub Copilot Pro ($20/mo), totalling $40/month. https://newsletter.pragmaticengineer.com/p/the-pulse-token-spend-breaks-budgets #aicoding

newsletter.pragmaticengineer.com

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David Foster @davidfstr@mastodon.world

· 5mo ago

Replying to

@fd93@fosstodon.org @Osmose@digipres.club 'any security measures like this "limit your productivity"' Heh, sure. You'll be more productive for a while but then lose your database or expose your customer PII, taking you to *before* square one. It's the same mistaken logic that fast (yet brittle/broken/missing) unit tests are always necessarily better than slow(er) (but thorough/correct) end-to-end tests.

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David Foster @davidfstr@mastodon.world

· 5mo ago

Replying to

@davidism@mas.to I chose "not nullable, default empty string" because I prefer data models where there is only 1 empty/error value. -- A comment situation where there are multiple empty/error values (to my dismay) is JavaScript, with its 2 sentinels: null and undefined.

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David Foster @davidfstr@mastodon.world

· 6mo ago

Replying to

@whitequark@social.treehouse.systems It’s funny: I work on mostly applications with GUI/web interfaces (with no expected dependent packages), where it’s frequently not clear what a “breaking change” would mean. So in practice I use romantic versioning a lot more than SemVer. https://dafoster.net/articles/2015/03/14/semantic-versioning-vs-romantic-versioning/

Semantic Versioning vs. Romantic Versioning | DaFoster

Semantic Versioning vs. Romantic Versioning | DaFoster

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