Clojure-flavored WASM text format | Hacker News Reader

Clojure-flavored WASM text format

github.com

112 pointstosh21 comments

Author here. The library is a toy project, it's far from being complete. Many things including macros are missing. Implementation style is derived from ClojureScript's compiler

It may be a toy, but I've been looking at doing very similar things at work. We have an optimizing compiler for spreadsheets, and many of the better optimizations are implemented as clojure syntax transforms (since Clojure was our first working target), so lowering that representation rather than selecting another is an attractive option, especially when compared to (for example) generating LLVM IR or code for some high level language.

Going offtopic, but...

>We have an optimizing compiler for spreadsheets

What is even a compiler for spreadsheets? In spreadsheets you still have an AST, or is it a different structure? Is there any fundamental property of spreadsheet code that enables specific optimizations?

It's more that it necessitates certain optimizations, rather than enabling them.

You need to figure out how and when to merge expressions, when it's worth it to extract a loop where the same expression needs to be compiled as two or three variants, because there are invariants between all but two or three of the invocations. You also must decide which collections you want to create out of the reference soup, when you can alias/discard collections and values, how to hoist predicates (for IF and SWITCH), when you can avoid type coercion. For small workbooks, just using tagged unions in a 2D array, plus a string pool, will suffice, but our sheets are so big that we can't afford that.

This looks great! Thanks for building it. Any plans on adding support for Collections and their functions? If that were to be added, I'd have a lot of use cases for this library already.

Does the order of the sections matter in the text format?

Been poking a bit here and there at a wasm binary parser and know in that format they're supposed be in order (with custom sections sprinkled wherever) but can't recall seeing anything about the text format order.

It looks great nonetheless.

I don't understand what this is, the readme is very sparse. Is it a compiler of Clojure targeting WASM?

Lets you emit text format of WASM from a Clojure style variation of the WASM sexp syntax. So no, it's not compiling Clojure.

It's a transpiler then, if my terminology is correct.

It's a transpiler/compiler, yes.

But it's not a Clojure->WASM transpiler/compiler, but Clojure-like->WASM transpiler/compiler, as only a subset of Clojure has been implemented and it's not compiling the standard library of Clojure into WASM.

Transpilers are compilers.

This is lovely, was just looking for something like this the other day. Gonna see if I can get this nicely integrated into a ClojureScript project and make the transition when writing code between js/wasm seamless. Thanks roman01la!

Is there any lightweight library to turn the wasm text format in to binary in the browser? I've seen emscripten compiled versions of the desktop compilers but nothing else.

wat2wasm can do that (part of https://github.com/webassembly/wabt). Since it's C++, I guess you could compile to it (wat2wasm) to webassembly to run in the browser as a library, and if it's works, no need for separate web/desktop version.

You might be able to find something more lightweight over here though: https://github.com/xtuc/webassemblyjs but I didn't find what you were looking for (but just did a quick look)

Schism – A self-hosting Scheme to WebAssembly compiler https://news.ycombinator.com/item?id=16488605

Such a beauty.

The implementation looks edicational too.

Would it be hard to add macros?

Glancing over the implementation it looks like you would have to add list manipulation ops to get macros to work, since there's no quote. So, not hard, but not trivial.

Shouldn't be too hard, implementation is derived from ClojureScript's analyzer. I'll probably add macros at some point.

I guess just usung Clojure macros would be an option.

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