Add a derive macro for Prism #101
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jplatte
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That was the last force-push, testing whether existing |
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| Ok(quote! { | ||
| #[derive(Clone)] | ||
| #enum_vis struct #name; |
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should we make it mod $enum_name { pub struct $variant_name; } instead of struct $enum_name$variant_name?
this is done in derive Lens
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I like that! I thought this kind of thing would require inherent associated types, great to hear it doesn't.
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Unfortunately this doesn't work because enum variants already exist in the value namespace (Option::Some in the value namespace is a function from T to Option<T>).
Because of rust-lang/rust#76347, I only got errors after fully implementing this idea 🙄
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Oh by the way the way druid does it / what almost worked wasn't mod $enum_name, it was mod $mod_name {} + impl #enum_name { pub const Some: $mod_name = $mod_name::Some; }.
The first approach immediately resulted in amibiguity errors between the enum and module.
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Here's the broken code that uses associated constants: jplatte@7a62a9b
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Cool, personally I think it's worth having a derive crate for the nursery, because there will probably be other codegen we want to experiment with, and because druid already requires syn/quote. We should make sure we use the same versions, so users don't have to build them twice.
The couple of small issues that @maan2003 identified can either be fixed before merge, or in a follow-up PR, either is fine.
Cargo.toml dep versions aren't exact by degault. Virtually everything uses syn & quote 1.x.y, so only one will be compiled. |
Yes sorry was more just thinking out loud. I don't expect it to be an issue. |
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Fixed the panic message and did some other refactorings, ready for another review :) |
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This is awesome! @jplatte, thank you so much :) |
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@maan2003 can this be merged? :) |
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Sure! |
cc @xarvic 🙂