Making your own programming language is easier than you think (but also harder)
50 points
2 days ago
| 14 comments
| lisyarus.github.io
| HN
sieve
20 minutes ago
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Anyone trying to do this... the first thing you do is avoid lex/yacc/bison/antlr. You do not need all this ceremony. A recursive descent parser that uses Pratt parsing will work for a vast majority of cases.

The lexer/parser is never the bottleneck. In fact, you can write those two by hand over a single weekend for a largish language. With LLMs, it takes 15 minutes if you have an unambiguous spec.

The biggest time sink, and the reason you will fail for sure, is the inability to restrict the scope of the project. You start with a limited feature set and produce the entire compiler/vm toolchain. Then you get greedy and fiddle with the type system, adding features that you have never used and probably never will. And now you have to change every single phase from start to end.

I mostly give up at this stage.

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sheepscreek
10 minutes ago
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Easier than you think to get started, but harder than you think to turn into something truly usable that isn’t a toy of an experiment.
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chrisaycock
29 minutes ago
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Yes, it's true that someone can put together a simple language like in a university course. The difficulties, as mentioned at the bottom of the post, are things like metaprogramming features or optimizing compilers.

The tail ends of a language implementation (parsing and code generation) are a fixed cost; the "middle end" can grow unbounded as more production-quality items are added.

My language: https://www.empirical-soft.com

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coldcode
58 minutes ago
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I wrote my own interpreted language about 25+ years ago to write online surveys. It made it easy to create complex surveys with many branches. I think I wrote it in Objective-C.

The team implementing the survey system wound up using the same language to implement the runtime portion, something I never expected or designed in.

I don't recall anything about what it looked like now. I do remember it was a lot of fun to write.

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amelius
1 hour ago
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Making a programming language is easy if you just copy ideas already existing in other languages.

Coming up with new ideas is hard. Especially since you have to test them in the real world.

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atan2
23 minutes ago
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This URL was posted two days ago: https://news.ycombinator.com/item?id=48040422
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gobdovan
1 hour ago
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I had a similar surprise about how approachable PL is, but from going from 'the bottom up' instead from a normal language.

I wrote a compiler toolchain and debugger that takes a Turing machine description plus input string and emits an encoded tape runnable by a Universal Turing Machine [0]. I had some prior PL experience, but never did an end-to-end compiler pipeline, at least not this low level.

It started as a joke/experiment, but I couldn't believe how fast it pulled me into designing:

- a small low-level ASM for building the UTM

- an ABI for symbol widths and encoding grammar

- an interpreter used as the behavioral oracle

- raw TM transitions for each ASM instruction, generated by having an LLM iterate on candidate emissions and checked against the interpreter oracle

- a CFG-style IR to fix the LLM mess once direct ASM -> TM emission became too hard to keep sane (LLM did a decent job actually, I don't think I would have done a much better job without the IR either)

- a gdb-style debugger for raw transitions, ASM routines, and blocks

- a trace visualizer

- a bootstrapping experiment where an L1 UTM/input pair was itself run through an L2 UTM

- optimisation experiments

And every step came quite naturally and was easy to tie in with everything else. Each one was just the next local repair needed to make the previous layer tractable.

[0] Repo: https://github.com/ouatu-ro/mtm

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nithinbekal
1 hour ago
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I've been having a lot of fun building my own programming language [1]. Getting to the point where you can write programs in your own language was surprisingly easy.

The language, Sapphire, is Ruby inspired, so the most interesting part is digging into the internals of the latter when I'm trying to figure out how something should work.

[1] https://github.com/sapphire-project/sapphire

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Tomokisan
39 minutes ago
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I watched a lot of youtube videos explaining in detail how to do it but i admit i never tried myself.

I'm kind of curious and want to try it for fun as long as i get some free time ^^

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virexene
3 hours ago
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this project is pretty interesting, although i'm wondering how they're planning to address the "easy sandboxing" design goal in a compiled language with raw pointer arithmetic and clib interop... in that regard i think lua would have been a lot easier to sandbox, despite the author's concerns.

(also, they might want to look into lua userdata, since that would address their concern about the overhead of converting between native and lua data structures. the language is designed to be embedded in C programs after all)

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ecto
1 hour ago
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There are many like it, but this one is mine https://loonlang.com
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smitty1e
3 hours ago
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If I were to make my own programming language, it would look an awful lot like Python.

Roughly 100%.

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cornholio
3 hours ago
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I agree, Python allows anyone to write bad code, but makes up for it by running the code slow enough that it can't do real damage.
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wildzzz
2 hours ago
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If someone smarter than me didn't think to invent a new language to solve what is likely a common problem, the solution already exists.
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applfanboysbgon
41 minutes ago
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It is absolutely not the case that all problems worth solving are solved already. Programming language development isn't necessarily about being a genius but rather a willingness to put in a monumental amount of work. Writing a language that compiles is easy enough. Getting a language off the ground to an actually useful place is tedious, simply in terms of the sheer amount of work to be done. Specification, implementation, documentation, diagnostics, optimization, configuration, tooling support, and creating a standard library (especially a cross-platform one) are things that will mire you in many hundreds of hours of work.
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cheschire
35 minutes ago
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Yeah except my version would only accept tabs instead of allowing (and even encouraging!!) spaces for indentation.
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unnouinceput
3 hours ago
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Making you own language is easy. Creating the library that will actually solve problems without forcing the developers to reinvent the wheel is the crux. There is a reason why C++ / Java / JavaScript etc are established, it's the already proven libraries around those languages that allows them to be so successful.
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Imustaskforhelp
3 hours ago
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I have only read the first end of the article but I can't help but think that a project like libriscv[0] would've/could've worked for their game project too because fun fact but the creator of librsicv, the legendary fwsgonzo is also making a game. I highly recommend for people to check out their discord server.

But my main point is that libriscv is one of the fastest libriscv emulators and then something like C/C++/lua could've been used with sandboxing purposes for the purposes of the game then.

Am I missing something? Although, making a programming language is one kind of its own projects and that's really cool as well :-D

but I would also love to hear the author's opinion on libriscv as it feels like it ticks of all the boxes from my understanding

[0]: https://github.com/libriscv/libriscv

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