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#![doc(html_root_url = "https://docs.rs/indoc-impl/0.2.8")]
#[cfg(feature = "unstable")]
extern crate proc_macro;
#[cfg(not(feature = "unstable"))]
#[macro_use]
extern crate proc_macro_hack;
extern crate proc_macro2;
extern crate syn;
#[macro_use]
extern crate quote;
extern crate unindent;
use unindent::*;
use proc_macro2::TokenStream;
use syn::{Lit, LitByteStr, LitStr};
use std::fmt::Debug;
use std::str::FromStr;
#[cfg(feature = "unstable")]
#[proc_macro]
pub fn indoc(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
expand(&input)
}
#[cfg(not(feature = "unstable"))]
proc_macro_expr_impl! {
pub fn indoc_impl(input: &str) -> String {
expand(input)
}
}
fn expand<T, R>(input: &T) -> R
where
T: ?Sized + ToString,
R: FromStr,
R::Err: Debug,
{
let source = input.to_string().parse::<TokenStream>().unwrap();
let len = source.clone().into_iter().count();
if len != 1 {
panic!(
"argument must be a single string literal, but got {} tokens",
len
);
}
let lit = match syn::parse2::<Lit>(source) {
Ok(lit) => lit,
Err(_) => {
panic!("argument must be a single string literal");
}
};
let lit = match lit {
Lit::Str(lit) => {
let v = unindent(&lit.value());
Lit::Str(LitStr::new(&v, lit.span()))
}
Lit::ByteStr(lit) => {
let v = unindent_bytes(&lit.value());
Lit::ByteStr(LitByteStr::new(&v, lit.span()))
}
_ => {
panic!("argument must be a single string literal");
}
};
quote!(#lit).to_string().parse().unwrap()
}