DeriveDisplay macro for enum #1726
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,128 @@ | ||
| use proc_macro2::TokenStream; | ||
| use quote::{quote, quote_spanned, ToTokens}; | ||
| use syn::{LitStr, LitInt}; | ||
|
|
||
| enum Error { | ||
| InputNotEnum, | ||
| Syn(syn::Error), | ||
| TT(TokenStream), | ||
| } | ||
|
|
||
| struct Display { | ||
| ident: syn::Ident, | ||
| variants: Vec<DisplayVariant>, | ||
| } | ||
|
|
||
| struct DisplayVariant { | ||
| ident: syn::Ident, | ||
| display_value: TokenStream, | ||
| } | ||
|
|
||
| impl Display { | ||
| fn new(input: syn::DeriveInput) -> Result<Self, Error> { | ||
| let ident = input.ident; | ||
|
|
||
| let variant_vec = match input.data { | ||
| syn::Data::Enum(syn::DataEnum { variants, .. }) => variants, | ||
| _ => return Err(Error::InputNotEnum), | ||
| }; | ||
|
|
||
|
|
||
| let mut variants = Vec::new(); | ||
| for variant in variant_vec { | ||
| let mut display_value = "".into_token_stream(); | ||
|
There was a problem hiding this comment. Maybe? let mut display_value = TokenStream::new();https://docs.rs/proc-macro2/latest/proc_macro2/struct.TokenStream.html |
||
| let variant_span = variant.ident.span(); | ||
| for attr in variant.attrs.iter() { | ||
| if !attr.path().is_ident("sea_orm") { | ||
| continue; | ||
| } | ||
| display_value = variant.ident.clone().to_token_stream(); | ||
| attr.parse_nested_meta(|meta| { | ||
| if meta.path.is_ident("string_value") { | ||
| Some(meta.value()?.parse::<LitStr>()?); | ||
| } else if meta.path.is_ident("num_value") { | ||
| Some(meta.value()?.parse::<LitInt>()?); | ||
| } else if meta.path.is_ident("display_value") { | ||
| display_value = meta.value()?.parse::<LitStr>()?.to_token_stream(); | ||
| } else { | ||
| return Err(meta.error(format!( | ||
| "Unknown attribute parameter found: {:?}", | ||
| meta.path.get_ident() | ||
| ))); | ||
| } | ||
|
|
||
| Ok(()) | ||
| }) | ||
| .map_err(Error::Syn)?; | ||
| } | ||
|
|
||
|
|
||
| variants.push(DisplayVariant { | ||
| ident: variant.ident, | ||
| display_value, | ||
| }); | ||
| } | ||
| Ok(Display { | ||
| ident, | ||
| variants, | ||
| }) | ||
| } | ||
|
|
||
| fn expand(&self) -> syn::Result<TokenStream> { | ||
| let expanded_impl_active_enum = self.impl_active_enum(); | ||
|
|
||
| Ok(expanded_impl_active_enum) | ||
| } | ||
|
|
||
| fn impl_active_enum(&self) -> TokenStream { | ||
| let Self { | ||
| ident, | ||
| variants | ||
| } = self; | ||
|
|
||
| let variant_idents: Vec<syn::Ident> = variants | ||
| .iter() | ||
| .map(|variant| variant.ident.clone()) | ||
| .collect(); | ||
|
|
||
| let variant_display: Vec<TokenStream> = variants | ||
| .iter() | ||
| .map(|variant| { | ||
| variant.display_value.to_owned() | ||
| }) | ||
| .collect(); | ||
| let debug_token = quote!( | ||
| impl #ident { | ||
darkmmon marked this conversation as resolved.
Show resolved
Hide resolved
|
||
| fn to_display_value(&self) -> String { | ||
| match self { | ||
| #( Self::#variant_idents => #variant_display, )* | ||
| } | ||
| .to_owned() | ||
| } | ||
| } | ||
|
|
||
| #[automatically_derived] | ||
| impl std::fmt::Display for #ident { | ||
| fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { | ||
| let v: sea_orm::sea_query::Value = Self::to_display_value(&self).into(); | ||
| write!(f, "{}", v) | ||
| } | ||
| } | ||
| ); | ||
| dbg!(debug_token.clone().to_string()); | ||
| debug_token | ||
| } | ||
| } | ||
|
|
||
| pub fn expand_derive_active_enum_display(input: syn::DeriveInput) -> syn::Result<TokenStream> { | ||
| let ident_span = input.ident.span(); | ||
|
|
||
| match Display::new(input) { | ||
| Ok(model) => model.expand(), | ||
| Err(Error::InputNotEnum) => Ok(quote_spanned! { | ||
| ident_span => compile_error!("you can only derive activeenum_Display on enums"); | ||
| }), | ||
| Err(Error::TT(token_stream)) => Ok(token_stream), | ||
| Err(Error::Syn(e)) => Err(e), | ||
| } | ||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I believe this is not needed?
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Since the code for DeriveActiveEnum will panic if there is some unrecognised attributes, I added this so that deriving both Display and Active Enum would not make the code panic.