syntax/doc.rs

use proc_macro2::TokenStream;
use quote::{quote, ToTokens};
use syn::LitStr;

pub struct Doc {
    fragments: Vec<LitStr>,
}

impl Doc {
    pub fn new() -> Self {
        Doc {
            fragments: Vec::new(),
        }
    }

    pub fn push(&mut self, lit: LitStr) {
        self.fragments.push(lit);
    }

    pub fn is_empty(&self) -> bool {
        self.fragments.is_empty()
    }

    pub fn to_string(&self) -> String {
        let mut doc = String::new();
        for lit in &self.fragments {
            doc += &lit.value();
            doc.push('\n');
        }
        doc
    }
}

impl ToTokens for Doc {
    fn to_tokens(&self, tokens: &mut TokenStream) {
        let fragments = &self.fragments;
        tokens.extend(quote! {
            #(#[doc = #fragments])*
        });
    }
}