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extern crate proc_macro;
use std::path::{Path, PathBuf};
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, AttrStyle, Attribute, DeriveInput, Lit, Meta, MetaNameValue};
use serde::{de::DeserializeOwned, Serialize};
trait Config<T>
where
T: Serialize + DeserializeOwned + Default,
{
fn load() -> Result<T, String>;
fn store() -> Result<(), String>;
}
fn is_outer_attribute(a: &Attribute) -> bool {
match a.style {
AttrStyle::Outer => true,
_ => false,
}
}
#[proc_macro_derive(Config, attributes(filename, filetype))]
pub fn config_attribute(item: TokenStream) -> TokenStream {
let mut ast: DeriveInput = syn::parse(item).unwrap();
let mut filename: Option<PathBuf> = None;
let mut filetype: Option<PathBuf> = None;
for option in ast.attrs.into_iter() {
let option = option.parse_meta().unwrap();
match option {
Meta::NameValue(MetaNameValue {
ref path, ref lit, ..
}) if path.is_ident("filename") => {
if let Lit::Str(f) = lit {
filename = Some(PathBuf::from(f.value()));
}
}
Meta::NameValue(MetaNameValue {
ref path, ref lit, ..
}) if path.is_ident("filetype") => {
if let Lit::Str(f) = lit {
filetype = Some(PathBuf::from(f.value()));
}
}
_ => {}
}
}
println!("{:?} {:?}", filename, filetype);
TokenStream::new()
}
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