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#![doc(html_root_url = "https://docs.rs/indoc-impl/0.2.1")]
#![cfg_attr(feature = "unstable", feature(proc_macro))]
#[cfg(feature = "unstable")]
extern crate proc_macro;
#[cfg(feature = "unstable")]
use proc_macro::TokenStream;
#[cfg(not(feature = "unstable"))]
#[macro_use]
extern crate proc_macro_hack;
extern crate syn;
#[macro_use]
extern crate quote;
extern crate unindent;
use unindent::*;
use syn::{TokenTree, Token, Lit};
use std::fmt::Debug;
use std::str::FromStr;
#[cfg(feature = "unstable")]
#[proc_macro]
pub fn indoc(input: TokenStream) -> 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();
let tts = syn::parse_token_trees(&source).unwrap();
if tts.len() != 1 {
panic!("argument must be a single string literal, but got {} arguments", tts.len());
}
let tt = tts.into_iter().next().unwrap();
let mut lit = match tt {
TokenTree::Token(Token::Literal(lit)) => lit,
_ => {
panic!("argument must be a single string literal");
}
};
match lit {
Lit::Str(ref mut s, _style) => {
*s = unindent(s);
}
Lit::ByteStr(ref mut v, _style) => {
*v = unindent_bytes(v);
}
_ => {
panic!("argument must be a single string literal");
}
}
quote!(#lit).parse().unwrap()
}