1 // SPDX-License-Identifier: Apache-2.0 OR MIT 2 3 use std::fmt::Display; 4 5 use proc_macro2::TokenStream; 6 use syn::{spanned::Spanned, Error}; 7 8 pub(crate) struct DiagCtxt(TokenStream); 9 pub(crate) struct ErrorGuaranteed(()); 10 11 impl DiagCtxt { 12 #[expect(dead_code)] 13 pub(crate) fn error(&mut self, span: impl Spanned, msg: impl Display) -> ErrorGuaranteed { 14 let error = Error::new(span.span(), msg); 15 self.0.extend(error.into_compile_error()); 16 ErrorGuaranteed(()) 17 } 18 19 #[expect(dead_code)] 20 pub(crate) fn with( 21 fun: impl FnOnce(&mut DiagCtxt) -> Result<TokenStream, ErrorGuaranteed>, 22 ) -> TokenStream { 23 let mut dcx = Self(TokenStream::new()); 24 match fun(&mut dcx) { 25 Ok(mut stream) => { 26 stream.extend(dcx.0); 27 stream 28 } 29 Err(ErrorGuaranteed(())) => dcx.0, 30 } 31 } 32 } 33