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use quote::quote;
mod captures;
mod impl_enum;
mod impl_struct;
#[proc_macro_derive(FromRegex, attributes(from_regex))]
pub fn derive_regex(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let input = syn::parse_macro_input!(input as syn::DeriveInput);
inner_impl_from_regex(&input, false).into()
}
#[proc_macro_derive(FromStr, attributes(from_regex))]
pub fn derive_str(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let input = syn::parse_macro_input!(input as syn::DeriveInput);
inner_impl_from_regex(&input, true).into()
}
const ATTRIBUTE: &str = "from_regex";
fn inner_impl_from_regex(
input: &syn::DeriveInput,
impl_from_str: bool,
) -> proc_macro2::TokenStream {
let syn::DeriveInput {
data, attrs, ident, ..
} = input;
let impl_from_regex = match data {
syn::Data::Enum(data_enum) => {
impl_enum::Item::new(ident, &attrs, data_enum.variants.iter()).impl_from_regex()
}
syn::Data::Struct(syn::DataStruct { fields, .. }) => {
impl_struct::Item::new(ident, &attrs, &fields).impl_from_regex()
}
_ => panic!("Unsupported item type"),
};
let impl_from_str = if impl_from_str {
quote! {
impl std::str::FromStr for #ident {
type Err = ();
fn from_str(s: &str) -> Result<Self, Self::Err> {
Self::from_regex(s).ok_or(())
}
}
}
} else {
quote! {}
};
quote! {
#impl_from_regex
#impl_from_str
}
}