Gary Guo | 70a21e5 | 2023-04-08 12:25:23 +0000 | [diff] [blame] | 1 | // SPDX-License-Identifier: Apache-2.0 OR MIT |
| 2 | |
| 3 | use proc_macro::{TokenStream, TokenTree}; |
| 4 | |
| 5 | pub(crate) trait ToTokens { |
| 6 | fn to_tokens(&self, tokens: &mut TokenStream); |
| 7 | } |
| 8 | |
| 9 | impl<T: ToTokens> ToTokens for Option<T> { |
| 10 | fn to_tokens(&self, tokens: &mut TokenStream) { |
| 11 | if let Some(v) = self { |
| 12 | v.to_tokens(tokens); |
| 13 | } |
| 14 | } |
| 15 | } |
| 16 | |
| 17 | impl ToTokens for proc_macro::Group { |
| 18 | fn to_tokens(&self, tokens: &mut TokenStream) { |
| 19 | tokens.extend([TokenTree::from(self.clone())]); |
| 20 | } |
| 21 | } |
| 22 | |
| 23 | impl ToTokens for TokenTree { |
| 24 | fn to_tokens(&self, tokens: &mut TokenStream) { |
| 25 | tokens.extend([self.clone()]); |
| 26 | } |
| 27 | } |
| 28 | |
| 29 | impl ToTokens for TokenStream { |
| 30 | fn to_tokens(&self, tokens: &mut TokenStream) { |
| 31 | tokens.extend(self.clone()); |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | /// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with |
| 36 | /// the given span. |
| 37 | /// |
| 38 | /// This is a similar to the |
| 39 | /// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the |
| 40 | /// `quote` crate but provides only just enough functionality needed by the current `macros` crate. |
Gary Guo | 70a21e5 | 2023-04-08 12:25:23 +0000 | [diff] [blame] | 41 | macro_rules! quote_spanned { |
Benno Lossin | b8342add | 2023-04-24 08:11:33 +0000 | [diff] [blame] | 42 | ($span:expr => $($tt:tt)*) => {{ |
| 43 | let mut tokens; |
| 44 | #[allow(clippy::vec_init_then_push)] |
| 45 | { |
| 46 | tokens = ::std::vec::Vec::new(); |
| 47 | let span = $span; |
| 48 | quote_spanned!(@proc tokens span $($tt)*); |
| 49 | } |
Gary Guo | 70a21e5 | 2023-04-08 12:25:23 +0000 | [diff] [blame] | 50 | ::proc_macro::TokenStream::from_iter(tokens) |
| 51 | }}; |
| 52 | (@proc $v:ident $span:ident) => {}; |
| 53 | (@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => { |
| 54 | let mut ts = ::proc_macro::TokenStream::new(); |
| 55 | $crate::quote::ToTokens::to_tokens(&$id, &mut ts); |
| 56 | $v.extend(ts); |
| 57 | quote_spanned!(@proc $v $span $($tt)*); |
| 58 | }; |
| 59 | (@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => { |
| 60 | for token in $id { |
| 61 | let mut ts = ::proc_macro::TokenStream::new(); |
| 62 | $crate::quote::ToTokens::to_tokens(&token, &mut ts); |
| 63 | $v.extend(ts); |
| 64 | } |
| 65 | quote_spanned!(@proc $v $span $($tt)*); |
| 66 | }; |
| 67 | (@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => { |
| 68 | let mut tokens = ::std::vec::Vec::new(); |
| 69 | quote_spanned!(@proc tokens $span $($inner)*); |
| 70 | $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( |
| 71 | ::proc_macro::Delimiter::Parenthesis, |
| 72 | ::proc_macro::TokenStream::from_iter(tokens) |
| 73 | ))); |
| 74 | quote_spanned!(@proc $v $span $($tt)*); |
| 75 | }; |
| 76 | (@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => { |
| 77 | let mut tokens = ::std::vec::Vec::new(); |
| 78 | quote_spanned!(@proc tokens $span $($inner)*); |
| 79 | $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( |
| 80 | ::proc_macro::Delimiter::Bracket, |
| 81 | ::proc_macro::TokenStream::from_iter(tokens) |
| 82 | ))); |
| 83 | quote_spanned!(@proc $v $span $($tt)*); |
| 84 | }; |
| 85 | (@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => { |
| 86 | let mut tokens = ::std::vec::Vec::new(); |
| 87 | quote_spanned!(@proc tokens $span $($inner)*); |
| 88 | $v.push(::proc_macro::TokenTree::Group(::proc_macro::Group::new( |
| 89 | ::proc_macro::Delimiter::Brace, |
| 90 | ::proc_macro::TokenStream::from_iter(tokens) |
| 91 | ))); |
| 92 | quote_spanned!(@proc $v $span $($tt)*); |
| 93 | }; |
| 94 | (@proc $v:ident $span:ident :: $($tt:tt)*) => { |
| 95 | $v.push(::proc_macro::TokenTree::Punct( |
| 96 | ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Joint) |
| 97 | )); |
| 98 | $v.push(::proc_macro::TokenTree::Punct( |
| 99 | ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone) |
| 100 | )); |
| 101 | quote_spanned!(@proc $v $span $($tt)*); |
| 102 | }; |
| 103 | (@proc $v:ident $span:ident : $($tt:tt)*) => { |
| 104 | $v.push(::proc_macro::TokenTree::Punct( |
| 105 | ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone) |
| 106 | )); |
| 107 | quote_spanned!(@proc $v $span $($tt)*); |
| 108 | }; |
| 109 | (@proc $v:ident $span:ident , $($tt:tt)*) => { |
| 110 | $v.push(::proc_macro::TokenTree::Punct( |
| 111 | ::proc_macro::Punct::new(',', ::proc_macro::Spacing::Alone) |
| 112 | )); |
| 113 | quote_spanned!(@proc $v $span $($tt)*); |
| 114 | }; |
| 115 | (@proc $v:ident $span:ident @ $($tt:tt)*) => { |
| 116 | $v.push(::proc_macro::TokenTree::Punct( |
| 117 | ::proc_macro::Punct::new('@', ::proc_macro::Spacing::Alone) |
| 118 | )); |
| 119 | quote_spanned!(@proc $v $span $($tt)*); |
| 120 | }; |
| 121 | (@proc $v:ident $span:ident ! $($tt:tt)*) => { |
| 122 | $v.push(::proc_macro::TokenTree::Punct( |
| 123 | ::proc_macro::Punct::new('!', ::proc_macro::Spacing::Alone) |
| 124 | )); |
| 125 | quote_spanned!(@proc $v $span $($tt)*); |
| 126 | }; |
Benno Lossin | 071cedc | 2023-08-14 08:46:41 +0000 | [diff] [blame] | 127 | (@proc $v:ident $span:ident ; $($tt:tt)*) => { |
| 128 | $v.push(::proc_macro::TokenTree::Punct( |
| 129 | ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone) |
| 130 | )); |
| 131 | quote_spanned!(@proc $v $span $($tt)*); |
| 132 | }; |
| 133 | (@proc $v:ident $span:ident + $($tt:tt)*) => { |
| 134 | $v.push(::proc_macro::TokenTree::Punct( |
| 135 | ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone) |
| 136 | )); |
| 137 | quote_spanned!(@proc $v $span $($tt)*); |
| 138 | }; |
Gary Guo | 70a21e5 | 2023-04-08 12:25:23 +0000 | [diff] [blame] | 139 | (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => { |
| 140 | $v.push(::proc_macro::TokenTree::Ident(::proc_macro::Ident::new(stringify!($id), $span))); |
| 141 | quote_spanned!(@proc $v $span $($tt)*); |
| 142 | }; |
| 143 | } |
| 144 | |
| 145 | /// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with |
| 146 | /// mixed site span ([`Span::mixed_site()`]). |
| 147 | /// |
| 148 | /// This is a similar to the [`quote!`](https://docs.rs/quote/latest/quote/macro.quote.html) macro |
| 149 | /// from the `quote` crate but provides only just enough functionality needed by the current |
| 150 | /// `macros` crate. |
| 151 | /// |
| 152 | /// [`Span::mixed_site()`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.mixed_site |
Gary Guo | 70a21e5 | 2023-04-08 12:25:23 +0000 | [diff] [blame] | 153 | macro_rules! quote { |
| 154 | ($($tt:tt)*) => { |
| 155 | quote_spanned!(::proc_macro::Span::mixed_site() => $($tt)*) |
| 156 | } |
| 157 | } |