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Comment by soulbadguy | Hacker News Reader

I don't think i fully agree. Yes it might be possible to design a programming language that have a better synergy with wasm than the one we currently have, but IMO this won't have a particularly big impact on dev prod or performance. wasm was design to be the target of current languages, so in a sense it does capture a lot of things that already exists or can be mapped easily to existing languages. Designing against wasm might create a case of overfiting. But only the future will tell.

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Here is a specific example, again using Python, of how a programming language not designed for WASM might not be ideal: suppose you are writing a Python script which is to be compiled to WASM and needs to import a function. How do you specify that in the script? There could be some Python function like `wasm_import("my_function", "u32", ["u32"])`, which allows the programmer to specify a function to be imported... and the problem with that is that in Python everything normally happens at runtime, but the compiler which is turning your script into a .wasm file needs to know in advance what functions you are going to import. So you face a dilemma: either you mess with the fundamental assumption of Python that everything happens at runtime, or you add new syntax which allows specifying metadata, or you use magic comments, or do some other hacky thing.

This might seem strange to those who are used to today's dominant WASM paradigm, where the programmer usually controls both the VM and the .wasm program — such as website developers who create a .wasm file and then also write the Javascript to load it into the browser. But one of the most exciting things about WASM, to me, is the potential for domain-specific execution environments in which the code which loads and executes the WASM is written much earlier and by a different entity than whoever writes the WASM.

I think the relatively less-hacky approach would be to have the python code use the 'import' syntax to get those functions, and then how you intercept those and redirect them to DTRT is a decision with multiple possible approaches depending on your preferred set of trade-offs.

In Perl I'd probably do something like having a .pm file that does

    package MyBindings;
    
    use v5.38;
    use Exporter 'import';
    
    our @EXPORT_OK = qw(function names to export go here);
    
    use Wasm::Bindings;
    
    my_function u32 [u32]
    other_function ...
    ...

where the stuff after 'use Wasm::Bindings' is some sort of import-defining DSL (I invented one to pseudocode in, there's probably a 'real' one already you'd be better using in practice) and the 'use Wasm::Bindings;' statement switches in a different parser for the rest of the file when you load it normally. Then you could have external tools that simply know 'ignore everything up to that use line, those lines are Perl code, everything after it is yours though and should be handled however required.'

You can register custom loaders in https://bun.sh/ that I think would let me provide similar functionality there (maybe via a .wasmbind file extension or similar) and vague memory says python has ways and means to do such things but I've not looked in some years.

(I suspect you're still right that a language designed for WASM will end up being more ergonomic in that regard even so, and also that over time we'll likely find other ways it's more ergonomic that I haven't currently thought of, but I still don't think the situation for other languages is -quite- as bad as you suggest)

The problem you are describing isn't really related to WASM or any particular target system or programming language. And targeting wasm wouldn't really address it. It looks to me like a packaging issue.

If i follow you correctly, you are simply saying that in python it's possible to refer to some code in a way that the compiler can't anticipate and thus can't make sure the relevant code is present at runtime.

First this a problem in pretty much every language. Even in very static languages like c++, one can dlopen his way into this exact situation. JVM/.Net also have missing classes situation when someone screw up the packaging

This is solved by having a sensible code laoding API. Java classloader or .NET equivalent manage that.

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