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9964 :: import module just for comptime use

[2023-03-02T19:30:28+01:00]

choltreppe (orginal) [2023-03-02T19:30:28+01:00] view original

So the situation Im in is that I have a project that needs marshal, but I only need it inside of macros. And I want to compile it to js. So that doesnt work because marshal doenst support js backend. But it could work in theory, because only the VM uses it.

Is there any way to import it only for compile-time use?

Nlits (orginal) [2023-03-02T20:06:46+01:00] view original

I was trying to figure this out once too, recently I found this: https://forum.nim-lang.org/t/7150 but it seems to be incomplete. It be nice to see compile-time imports.

Araq (orginal) [2023-03-02T23:22:50+01:00] view original

In theory there is no need for it since the JS codegen only translates to JS what is used at runtime, not at compile-time. In practice though some modules like marshal.nim might not yet be ready for it.

DeletedUser (orginal) [2023-03-02T23:38:25+01:00] view original

This is because of the bad API of the marshal module. The actual code in the marshal module only works on native backends, but there are hidden hooks for the VM in $$ and to. If I had to guess, these hooks should be in a separate module and not conflated with the native $$ and to in marshal

PMunch (orginal) [2023-03-04T10:21:54+01:00] view original

Yes, this issue is very annoying. Especially for modules like OS which explicitly throws an error.. I made an dssue about it here, but alas nothing has come of it so far https://github.com/nim-lang/Nim/issues/19414