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Comment by jaredly | Hacker News Reader

Source control does look very different in a projectional language, as git diffs no longer make much sense (viewing a pull-request with the source tree's JSON blob is essentially useless).

Unison is the language that's gone farthest with this, as far as I know; their solution to diffs & merges is to handle everything from within their CLI, bypassing git entirely. I imagine I'll do something similar.

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I don't know anything about how you're storing the source, but if the data elided from view could be stored in files next to the source that were more readable than JSON, you could potentially take advantage of the whole git ecosystem still. People could put code up for review and the reviewers could even confirm if the additional (normally out of sight) information made sense to them.

FWIW, I'm totally on board with the idea of focusing on the interactive experience, but history has shown it to be very difficult for language environments not based on files to cross the chasm into more common use. (If you don't care about lots of users, then ignore this entire comment! Plus, it's always _possible_ that something will cross over, but we've got decades of people trying...)

Anyhow, I'm really excited to see where you go with this!

Oh hi kevin! So if there's a possibility that the "extra data" would get out of sync with the "source code" (e.g. via a git merge, or someone just editing the source code as plain text), then it unfortunately breaks the guarantees that this system needs :( I guess I could store a sha of each and fail loudly if I detect that one was edited "outside of the IDE" but again I think that would break the assumptions that git makes about diffs &c. I've tried to go down the "text but nicer" route before, and it always comes up short; so now I'm trying "text is not a supported representation" we'll see how far I get.

Hey Jared :)

Yeah, good point that text is a potentially fragile approach when combined with git. I think the Squeak Smalltalk folks figured out a way to retrofit git support, so maybe it's possible to go all-in on the representation you want and work out git support later if it seems useful enough.

If I may, I’d suggest instead of shunning git, which is widely preferred as people’s revision control, perhaps consider writing a diff plugin for git to render out the diffs nicely, and include that tool with the compiler/interpreter install.

This hits on the biggest problem with projectional languages, and why text has dominated: they don't interoperate well with any existing developer tooling.

So the language implementors have to write everything the developer needs: code editor, source control, code review, code browser, etc

You're completely isolated from the wider ecosystem of development, and the benefits so far don't seem worth it. As described here, you save on the reference resolution phase of linking, which is nice, it should be faster and eliminate some classes of error.

The nice part about text as a common format is that it's common. If every language has to implement every tool then it's an N * M problem. When tools can be reused across languages they become N + M.

A user of a projectional language is giving up git, Github, their favorite code editor, and depending on language-specific tooling to replace all of that. And even when the lang-specific tooling is sufficient, it needs to be relearned and recustomized (think all the configuration just in a code editor: prefs, theme, extensions like VIM keybinds and Copilot, etc).

Is the benefit worth the cost?

> bypassing git entirely. I imagine I'll do something similar.

So I'm assuming your language will have some sort of custom source code management system? If so, what do you do when a user wants to store a non-code file together with the source code, e.g. how web applications might have CSS files, fonts and image assets in the repo?

So the "repo" in this case is a database, where currently the only things stored are denormalized source tree nodes. I could imagine extending the database to support arbitrary assets, probably also addressed by the hash of their contents (same as top-level language definitions are).

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