readline VS oil

... I kind of am, though. Which is why I didn't know what to do. I don't see a lot of free open source projects with extensive documentation in their README. Some, yes, but for example here's the readline library I'm using. I, in my well-meaning ignorance, supplied 50 pages of documentation and people are behaving like I ate a baby 'cos it's in the wrong format. I will now put it all in the README as people would like, but I did genuinely act out of ignorance and not out of a wish to insult the customs of the tribe.

> I would like to see a framework for creating rich REPLs that would be language agnostic, so that I could get a state of the art auto-completion dialog no matter which language I decided to make into a shell.

It's doable with existing tools. You have LSP to provide the syntactical framework and there's no shortage of alternatives to readline (I'd written my own[1] to use in murex[2], and open sourced that).

[1] https://github.com/lmorg/readline

[2] https://murex.rocks

The problem you still face is that a good shell will offer autocompletion suggestions for strings that aren't language keywords or function names. eg

- file names; and there's a lot of hidden logic in how to do this. Do you build in fzf-like support, just include fzf wholesale but increase your dependency tree, or go for basic path completion. Do you check metadata (eg hidden files and system files on Windows), include dot-prefixed files on Linux / UNIX, etc. How do you know when to return paths, or paths and files, or even know not to return disk items at all? (see next point)

- flags for existing CLI tools (assuming you want compatibility with existing tools). Fish and murex will parse man pages to populate suggestions, others rely entirely on the community to write autocompletion scripts.

- Are you including variables in your completion of strings. And if so are you reading the variables to spot if it's a path and then following that path. eg `cd $HOME/[tab]` should then return items inside a your home directory even though you've not actually specified your home directory as a string. That means the shell needs to expand the variables to see if it's a valid path. But that's a shell decision rather than a language feature.

Some of these lists might take a while to populate so you then have another problem. Do you delay the autocompletion list (bad UX because it slows the user down) or provide the autocompletion sooner. And if the latter, how do you do that without:

1. changing the items under what you're about to select causing you to accidentally select the wrong option

2. communicate that there are update clearly

3. ensure the UI is consistent when slower loading entries might not fit the same dimensions as the space allocated for the list (if you dynamically size your completions to fit the screen real estate)

4. ensure that there's still something present while you're lazy loading the rest of the suggestions; and that those early entries on the completion list are worthwhile and accurate

5. what about sorting the list? Alphabetical? By feature? etc

The REPL in murex was inspired by IDEs so I've spent a lot of time trying to consider how to provide the best UX around autocompletion. One thing I've learnt is that it's a lot harder to get right than it seems on the surface.

will prevent almost all of the "silent footguns".

YSH has strict:all and then a bunch of NEW features.

There's been good feedback recently, which has led to many concrete changes. So your experience can definitely influence the language! https://github.com/oilshell/oil/wiki/Where-To-Send-Feedback

Regarding writing tools/tests/benchmarks in bash+Python, vs. writing tools in your main language:

I think we might eventually concede that something Debian-like is the “standard development environment” (at least for server side stuff, i.e. not iOS apps)

In this case, bash+Python is a non-issue. It works extremely reliably. That’s actually why I use it! Everything else seems to break, or it’s really slow (node.js is a very common alternative).

- Microsoft conceded this back in ~2017, by building Linux into their kernel with WSL, and providing Ubuntu on top

Yes bash + Python is a disaster on Windows (I have scars from it), but Microsoft agrees that the right place to solve that is in Windows :-)

- Every CI system runs Debian/Ubuntu

- Every hosting provider runs Debian/Ubuntu

- Every online dev env like gitpod.io provides Debian/Ubuntu

This is somewhat related to remote dev envs: https://lobste.rs/s/ucirlx/lapdev_self_hosted_remote_dev

One vision for https://www.oilshell.org/ is that the CI environment is the dev environment is the hosting environment.

Everything is just an equal node in a distributed system. BUT it’s more git like, in that you explicitly sync and work “locally”, wherever that is. You don’t have the network chatter and flakiness of “the cloud”.

Oils has a very large set of monotonically increasing properties too - https://www.oilshell.org/release/0.21.0/quality.html

All that is bash+Python that is run on every commit, and it’s extremely good at catching bugs and perf regressions.

I’m skeptical that any project has that level of quality automation written in pure Rust or Zig. More likely it’s a bunch of cloud services with YAML.

Also a bunch of “hard-coded” toolchains that you can’t script with bespoke code. Like some shell commands in your package.json, which is just a worse way of writing a shell script.

Our quality process is all self-hosted, in the repo, and runs on both Github Actions and sourcehut - https://www.oilshell.org/release/0.21.0/pub/metrics.wwz/line...

bash and Python runs perfectly on Github Actions and sourcehut, with zero change. Containers also do.

(Although we need to unify the CI and release, because the release runs on 2 different real hardware machines, while CI is cloud only.)

Also, a main point Oils is that bash now has another highly compatible, spec-driven implementation – OSH. Having 2 independent implementations is something newer languages don’t have.

(copy of lobste.rs comment)

in your bashrc to enable it. I've used it for probably ~18 years now.

It also works with https://www.oilshell.org/ since we use GNU readline. Just 'set -o vi' in ~/.config/oils/oshrc

No other shell does that.

But I didn't know it was called MULTIOS until now. (I guess that's read "mult I/O's"? I have a hard time not reading it was multi-OS :) )

It seems a bit niche to be honest, but it's possible to support in Oils.

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Oils also uses Unix domain sockets already for the headless shell protocol

https://github.com/oilshell/oil/wiki/Headless-Mode

We could do something like dgsh, but so far I haven't seen a lot of uptake / demand. Every time it's mentioned, somebody kinda wants it, and then it kinda peters out again ... still possible though.

I think flat files work fine for a lot of use cases, and once you add streaming, you also want monitoring, more control over backpressure/queue sizes, etc.

which works well. You don't have to clean when rebuilding variants. IMO this is 100% essential for writing C++ these days. You need a bunch of test binaries, and all tests should be run with ASAN and UBSAN.

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I wrote a mini-bazel on top of Ninja with these features:

https://www.oilshell.org/blog/2022/10/garbage-collector.html...

So it's ~1700 lines, but for that you get the build macros like asdl_library() generating C++ and Python (the same as proto_library(), a schema language that generates code)

And it also correctly finds dependencies of code generators. So if you change a .py file that is imported by another .py file that is used to generated a C++ header, everything will work. That was one of the trickier bits, with Ninja implicit dependencies.

I also use the Bazel-target syntax like //core/process

This build file example mixes low level Ninja n.rule() and n.build() with high level r.cc_library() and so forth. I find this layering really does make it scale better for bigger projects

https://github.com/oilshell/oil/blob/master/asdl/NINJA_subgr...

Some more description - https://lobste.rs/s/qnb7xt/ninja_is_enough_build_system#c_tu...

This is sort of a category error...

re2c is a lexer generator, and YAML and Python are recursive/nested formats.

You can definitely use re2c to lex them, but it's not the whole solution.

I use it for everything possible in https://www.oilshell.org, and it's amazing. It really reduces the amount of fiddly C code you need to parse languages, and it drops in anywhere.

SEEKING VOLUNTEERS - https://www.oilshell.org/ - https://github.com/oilshell/oil/

I'm looking for people to help fill out the "standard library" for Oils/YSH. We're implementing a shell for Python and JavaScript programmers who avoid shell!

On the surface, this is writing some very simple functions in typed Python. But I've realized that the hardest parts are specifying, TESTING, and documenting what the functions do.

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The most recent release announcement also asks for help - https://www.oilshell.org/blog/2024/01/release-0.19.0.html (long)

If you find all those details interesting (if maybe overwhelming), you might have a mind for language design, and could be a good person to help.

Surveying what Python and JavaScript do is very helpful, e.g. for the recent Str.replace() function, which is nontrivial (takes a regex or string, replacement template or string)

But there are also very simple methods to get started, like Dict.values() and List.indexOf(). Other people have already contributed code. Examples:

https://github.com/oilshell/oil/commit/58d847008427dba2e60fe...

https://github.com/oilshell/oil/commit/8f38ee36d01162593e935...

This can also be useful to tell if you'll have fun working on the project - https://github.com/oilshell/oil/wiki/Where-Contributors-Have...

More on #help-wanted on Zulip (requires login) - https://oilshell.zulipchat.com/#narrow/stream/417617-help-wa...

Please send a message on Github or Zulip! Or e-mail me andy at oilshell dot org.

This is true, but then the corrolary is that new PRs need to come with this higher and rigorous level of test coverage.

And then that becomes a bit of a barrier to contribution -- that's a harness

I often write entirely new test harnesses for features, e.g. for https://www.oilshell.org, many of them linked here . All of these run in the CI - https://www.oilshell.org/release/latest/quality.html

The good thing is that it definitely helps me accept PRs faster. Current contributors are good at this kind of exhaustive testing, but many PRs aren't