respan 0.1.6

Macros to erase scope information from tokens
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54

//! [![github]](https://github.com/dtolnay/respan) [![crates-io]](https://crates.io/crates/respan) [![docs-rs]](https://docs.rs/respan)
//!
//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs
//!
//! <br>
//!
//! Macros to erase scope information from tokens.
//!
//! # Example
//!
//! ```no_run
//! #![forbid(unsafe_code)]
//!
//! fn main() {
//!     let ptr = 1337 as *const i32;
//!     let value = respan::call_site! {
//!         unsafe { *ptr }
//!     };
//!     println!("{}", value);
//! }
//! ```

#![doc(html_root_url = "https://docs.rs/respan/0.1.6")]
#![allow(clippy::needless_doctest_main)]

use proc_macro::{Group, Span, TokenStream, TokenTree};

#[proc_macro]
pub fn call_site(input: TokenStream) -> TokenStream {
    respan(input, Span::call_site())
}

#[proc_macro]
pub fn mixed_site(input: TokenStream) -> TokenStream {
    respan(input, Span::mixed_site())
}

fn respan(input: TokenStream, site: Span) -> TokenStream {
    input
        .into_iter()
        .map(|mut token| {
            let original_span = token.span();
            if let TokenTree::Group(group) = &mut token {
                let delimiter = group.delimiter();
                let stream = respan(group.stream(), site);
                *group = Group::new(delimiter, stream);
            }
            token.set_span(original_span.resolved_at(site));
            token
        })
        .collect()
}