cote-derive 0.12.2

Quickly build your command line utils
Documentation 
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mod config;
mod r#gen;
mod value;

use quote::quote;
use r#gen::CoteGenerator;
use r#gen::FetchGenerator;
use r#gen::InferGenerator;
use r#gen::ValueGenerator;
use syn::parse_macro_input;
use syn::spanned::Spanned;
use syn::DataEnum;
use syn::DeriveInput;

fn error(spanned: impl Spanned, msg: impl Into<String>) -> syn::Error {
    syn::Error::new(spanned.span(), msg.into())
}

#[proc_macro_derive(Cote, attributes(cote, arg, pos, cmd, sub))]
pub fn parser(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input: DeriveInput = parse_macro_input!(input);
    let generator = |input: DeriveInput| -> syn::Result<proc_macro2::TokenStream> {
        let mut cg = CoteGenerator::new(&input)?;

        cg.gen_impl_for_struct()
    };

    let ts = generator(input).unwrap_or_else(syn::Error::into_compile_error);

    quote! {
        #ts
    }
    .into()
}

#[proc_macro_derive(CoteOpt, attributes(infer, fetch))]
pub fn parser_opt(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input: DeriveInput = parse_macro_input!(input);
    let generator = |input| -> syn::Result<proc_macro2::TokenStream> {
        let fg = FetchGenerator::new(input)?;
        let ig = InferGenerator::new(input)?;
        let fg = fg.gen_impl_for_struct()?;
        let ig = ig.gen_impl_for_struct()?;

        Ok(quote::quote! { #fg #ig })
    };

    generator(&input)
        .unwrap_or_else(syn::Error::into_compile_error)
        .into()
}

#[proc_macro_derive(CoteVal, attributes(coteval))]
pub fn parser_enum(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input: DeriveInput = parse_macro_input!(input);
    let generator = |input, variants| ValueGenerator::new(input, variants)?.gen_impl_for_enum();
    let ts = generator(
        &input,
        if let syn::Data::Enum(DataEnum { ref variants, .. }) = &input.data {
            Some(variants)
        } else {
            None
        },
    )
    .unwrap_or_else(syn::Error::into_compile_error);

    ts.into()
}