msrd0/deprecated-gotham-restful
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remove panics from FromBody

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This commit is contained in:
Dominic 2020-04-08 21:53:57 +02:00
parent 2b8ad48504
commit f677789747
Signed by: msrd0
GPG key ID: DCC8C247452E98F9
1 changed files with 15 additions and 6 deletions
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21
gotham_restful_derive/src/from_body.rs
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@ -1,15 +1,25 @@
use proc_macro::TokenStream;
use proc_macro2::TokenStream as TokenStream2;
use quote::quote;
use syn::{
spanned::Spanned,
Error,
Fields,
ItemStruct,
parse_macro_input
};
pub fn expand_from_body(tokens : TokenStream) -> TokenStream
{
expand(tokens)
.unwrap_or_else(|err| err.to_compile_error())
.into()
}
fn expand(tokens : TokenStream) -> Result<TokenStream2, Error>
{
let krate = super::krate();
let input = parse_macro_input!(tokens as ItemStruct);
let input = parse_macro_input::parse::<ItemStruct>(tokens)?;
let ident = input.ident;
let generics = input.generics;
@ -24,7 +34,7 @@ pub fn expand_from_body(tokens : TokenStream) -> TokenStream
let field_ty = &field.ty;
(quote!(where #field_ty : for<'a> From<&'a [u8]>), quote!(Self { #field_ident: body.into() }))
},
_ => panic!("FromBody can only be derived for structs with at most one field")
_ => return Err(Error::new(fields.into_iter().nth(1).unwrap().span(), "FromBody can only be derived for structs with at most one field"))
}
},
Fields::Unnamed(unnamed) => {
@ -36,13 +46,13 @@ pub fn expand_from_body(tokens : TokenStream) -> TokenStream
let field_ty = &field.ty;
(quote!(where #field_ty : for<'a> From<&'a [u8]>), quote!(Self(body.into())))
},
_ => panic!("FromBody can only be derived for structs with at most one field")
_ => return Err(Error::new(fields.into_iter().nth(1).unwrap().span(), "FromBody can only be derived for structs with at most one field"))
}
},
Fields::Unit => (quote!(), quote!(Self{}))
};
let output = quote! {
Ok(quote! {
impl #generics #krate::FromBody for #ident #generics
#were
{
@ -54,6 +64,5 @@ pub fn expand_from_body(tokens : TokenStream) -> TokenStream
Ok(#body)
}
}
};
output.into()
})
}