Matthew Maurer | dc6194e | 2020-06-02 11:15:18 -0700 | [diff] [blame] | 1 | use proc_macro2::{Ident, Span, TokenStream}; |
| 2 | use quote::ToTokens; |
| 3 | use std::ops::{Deref, DerefMut}; |
| 4 | use syn::LitStr; |
| 5 | |
| 6 | /// An entity with a span attached. |
| 7 | #[derive(Debug, Clone)] |
| 8 | pub struct Sp<T> { |
| 9 | span: Span, |
| 10 | val: T, |
| 11 | } |
| 12 | |
| 13 | impl<T> Sp<T> { |
| 14 | pub fn new(val: T, span: Span) -> Self { |
| 15 | Sp { val, span } |
| 16 | } |
| 17 | |
| 18 | pub fn call_site(val: T) -> Self { |
| 19 | Sp { |
| 20 | val, |
| 21 | span: Span::call_site(), |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | pub fn span(&self) -> Span { |
| 26 | self.span |
| 27 | } |
| 28 | } |
| 29 | |
| 30 | impl<T> Deref for Sp<T> { |
| 31 | type Target = T; |
| 32 | |
| 33 | fn deref(&self) -> &T { |
| 34 | &self.val |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | impl<T> DerefMut for Sp<T> { |
| 39 | fn deref_mut(&mut self) -> &mut T { |
| 40 | &mut self.val |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | impl From<Ident> for Sp<String> { |
| 45 | fn from(ident: Ident) -> Self { |
| 46 | Sp { |
| 47 | val: ident.to_string(), |
| 48 | span: ident.span(), |
| 49 | } |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | impl From<LitStr> for Sp<String> { |
| 54 | fn from(lit: LitStr) -> Self { |
| 55 | Sp { |
| 56 | val: lit.value(), |
| 57 | span: lit.span(), |
| 58 | } |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | impl<'a> From<Sp<&'a str>> for Sp<String> { |
| 63 | fn from(sp: Sp<&'a str>) -> Self { |
| 64 | Sp::new(sp.val.into(), sp.span) |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | impl<T: PartialEq> PartialEq<T> for Sp<T> { |
| 69 | fn eq(&self, other: &T) -> bool { |
| 70 | self.val == *other |
| 71 | } |
| 72 | } |
| 73 | |
| 74 | impl<T: PartialEq> PartialEq for Sp<T> { |
| 75 | fn eq(&self, other: &Sp<T>) -> bool { |
| 76 | self.val == **other |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | impl<T: AsRef<str>> AsRef<str> for Sp<T> { |
| 81 | fn as_ref(&self) -> &str { |
| 82 | self.val.as_ref() |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | impl<T: ToTokens> ToTokens for Sp<T> { |
| 87 | fn to_tokens(&self, stream: &mut TokenStream) { |
| 88 | // this is the simplest way out of correct ones to change span on |
| 89 | // arbitrary token tree I can come up with |
| 90 | let tt = self.val.to_token_stream().into_iter().map(|mut tt| { |
Chih-Hung Hsieh | ad4a5aa | 2020-10-06 15:19:28 -0700 | [diff] [blame] | 91 | tt.set_span(self.span); |
Matthew Maurer | dc6194e | 2020-06-02 11:15:18 -0700 | [diff] [blame] | 92 | tt |
| 93 | }); |
| 94 | |
| 95 | stream.extend(tt); |
| 96 | } |
| 97 | } |