//! [![github]](https://github.com/dtolnay/quote) [![crates-io]](https://crates.io/crates/quote) [![docs-rs]](https://docs.rs/quote) //! //! [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 //! //!
//! //! This crate provides the [`quote!`] macro for turning Rust syntax tree data //! structures into tokens of source code. //! //! [`quote!`]: macro.quote.html //! //! Procedural macros in Rust receive a stream of tokens as input, execute //! arbitrary Rust code to determine how to manipulate those tokens, and produce //! a stream of tokens to hand back to the compiler to compile into the caller's //! crate. Quasi-quoting is a solution to one piece of that — producing //! tokens to return to the compiler. //! //! The idea of quasi-quoting is that we write *code* that we treat as *data*. //! Within the `quote!` macro, we can write what looks like code to our text //! editor or IDE. We get all the benefits of the editor's brace matching, //! syntax highlighting, indentation, and maybe autocompletion. But rather than //! compiling that as code into the current crate, we can treat it as data, pass //! it around, mutate it, and eventually hand it back to the compiler as tokens //! to compile into the macro caller's crate. //! //! This crate is motivated by the procedural macro use case, but is a //! general-purpose Rust quasi-quoting library and is not specific to procedural //! macros. //! //! ```toml //! [dependencies] //! quote = "1.0" //! ``` //! //!
//! //! # Example //! //! The following quasi-quoted block of code is something you might find in [a] //! procedural macro having to do with data structure serialization. The `#var` //! syntax performs interpolation of runtime variables into the quoted tokens. //! Check out the documentation of the [`quote!`] macro for more detail about //! the syntax. See also the [`quote_spanned!`] macro which is important for //! implementing hygienic procedural macros. //! //! [a]: https://serde.rs/ //! [`quote_spanned!`]: macro.quote_spanned.html //! //! ``` //! # use quote::quote; //! # //! # let generics = ""; //! # let where_clause = ""; //! # let field_ty = ""; //! # let item_ty = ""; //! # let path = ""; //! # let value = ""; //! # //! let tokens = quote! { //! struct SerializeWith #generics #where_clause { //! value: &'a #field_ty, //! phantom: core::marker::PhantomData<#item_ty>, //! } //! //! impl #generics serde::Serialize for SerializeWith #generics #where_clause { //! fn serialize(&self, serializer: S) -> Result //! where //! S: serde::Serializer, //! { //! #path(self.value, serializer) //! } //! } //! //! SerializeWith { //! value: #value, //! phantom: core::marker::PhantomData::<#item_ty>, //! } //! }; //! ``` //! //!
//! //! # Non-macro code generators //! //! When using `quote` in a build.rs or main.rs and writing the output out to a //! file, consider having the code generator pass the tokens through //! [prettyplease] before writing. This way if an error occurs in the generated //! code it is convenient for a human to read and debug. //! //! [prettyplease]: https://github.com/dtolnay/prettyplease // Quote types in rustdoc of other crates get linked to here. #![doc(html_root_url = "https://docs.rs/quote/1.0.32")] #![allow( clippy::doc_markdown, clippy::missing_errors_doc, clippy::missing_panics_doc, clippy::module_name_repetitions, // false positive https://github.com/rust-lang/rust-clippy/issues/6983 clippy::wrong_self_convention, )] extern crate alloc; #[cfg(feature = "proc-macro")] extern crate proc_macro; mod ext; mod format; mod ident_fragment; mod to_tokens; // Not public API. #[doc(hidden)] #[path = "runtime.rs"] pub mod __private; pub use crate::ext::TokenStreamExt; pub use crate::ident_fragment::IdentFragment; pub use crate::to_tokens::ToTokens; // Not public API. #[doc(hidden)] pub mod spanned; /// The whole point. /// /// Performs variable interpolation against the input and produces it as /// [`proc_macro2::TokenStream`]. /// /// Note: for returning tokens to the compiler in a procedural macro, use /// `.into()` on the result to convert to [`proc_macro::TokenStream`]. /// /// [`TokenStream`]: https://docs.rs/proc-macro2/1.0/proc_macro2/struct.TokenStream.html /// ///
/// /// # Interpolation /// /// Variable interpolation is done with `#var` (similar to `$var` in /// `macro_rules!` macros). This grabs the `var` variable that is currently in /// scope and inserts it in that location in the output tokens. Any type /// implementing the [`ToTokens`] trait can be interpolated. This includes most /// Rust primitive types as well as most of the syntax tree types from the [Syn] /// crate. /// /// [`ToTokens`]: trait.ToTokens.html /// [Syn]: https://github.com/dtolnay/syn /// /// Repetition is done using `#(...)*` or `#(...),*` again similar to /// `macro_rules!`. This iterates through the elements of any variable /// interpolated within the repetition and inserts a copy of the repetition body /// for each one. The variables in an interpolation may be a `Vec`, slice, /// `BTreeSet`, or any `Iterator`. /// /// - `#(#var)*` — no separators /// - `#(#var),*` — the character before the asterisk is used as a separator /// - `#( struct #var; )*` — the repetition can contain other tokens /// - `#( #k => println!("{}", #v), )*` — even multiple interpolations /// ///
/// /// # Hygiene /// /// Any interpolated tokens preserve the `Span` information provided by their /// `ToTokens` implementation. Tokens that originate within the `quote!` /// invocation are spanned with [`Span::call_site()`]. /// /// [`Span::call_site()`]: https://docs.rs/proc-macro2/1.0/proc_macro2/struct.Span.html#method.call_site /// /// A different span can be provided through the [`quote_spanned!`] macro. /// /// [`quote_spanned!`]: macro.quote_spanned.html /// ///
/// /// # Return type /// /// The macro evaluates to an expression of type `proc_macro2::TokenStream`. /// Meanwhile Rust procedural macros are expected to return the type /// `proc_macro::TokenStream`. /// /// The difference between the two types is that `proc_macro` types are entirely /// specific to procedural macros and cannot ever exist in code outside of a /// procedural macro, while `proc_macro2` types may exist anywhere including /// tests and non-macro code like main.rs and build.rs. This is why even the /// procedural macro ecosystem is largely built around `proc_macro2`, because /// that ensures the libraries are unit testable and accessible in non-macro /// contexts. /// /// There is a [`From`]-conversion in both directions so returning the output of /// `quote!` from a procedural macro usually looks like `tokens.into()` or /// `proc_macro::TokenStream::from(tokens)`. /// /// [`From`]: https://doc.rust-lang.org/std/convert/trait.From.html /// ///
/// /// # Examples /// /// ### Procedural macro /// /// The structure of a basic procedural macro is as follows. Refer to the [Syn] /// crate for further useful guidance on using `quote!` as part of a procedural /// macro. /// /// [Syn]: https://github.com/dtolnay/syn /// /// ``` /// # #[cfg(any())] /// extern crate proc_macro; /// # extern crate proc_macro2; /// /// # #[cfg(any())] /// use proc_macro::TokenStream; /// # use proc_macro2::TokenStream; /// use quote::quote; /// /// # const IGNORE_TOKENS: &'static str = stringify! { /// #[proc_macro_derive(HeapSize)] /// # }; /// pub fn derive_heap_size(input: TokenStream) -> TokenStream { /// // Parse the input and figure out what implementation to generate... /// # const IGNORE_TOKENS: &'static str = stringify! { /// let name = /* ... */; /// let expr = /* ... */; /// # }; /// # /// # let name = 0; /// # let expr = 0; /// /// let expanded = quote! { /// // The generated impl. /// impl heapsize::HeapSize for #name { /// fn heap_size_of_children(&self) -> usize { /// #expr /// } /// } /// }; /// /// // Hand the output tokens back to the compiler. /// TokenStream::from(expanded) /// } /// ``` /// ///


/// /// ### Combining quoted fragments /// /// Usually you don't end up constructing an entire final `TokenStream` in one /// piece. Different parts may come from different helper functions. The tokens /// produced by `quote!` themselves implement `ToTokens` and so can be /// interpolated into later `quote!` invocations to build up a final result. /// /// ``` /// # use quote::quote; /// # /// let type_definition = quote! {...}; /// let methods = quote! {...}; /// /// let tokens = quote! { /// #type_definition /// #methods /// }; /// ``` /// ///


/// /// ### Constructing identifiers /// /// Suppose we have an identifier `ident` which came from somewhere in a macro /// input and we need to modify it in some way for the macro output. Let's /// consider prepending the identifier with an underscore. /// /// Simply interpolating the identifier next to an underscore will not have the /// behavior of concatenating them. The underscore and the identifier will /// continue to be two separate tokens as if you had written `_ x`. /// /// ``` /// # use proc_macro2::{self as syn, Span}; /// # use quote::quote; /// # /// # let ident = syn::Ident::new("i", Span::call_site()); /// # /// // incorrect /// quote! { /// let mut _#ident = 0; /// } /// # ; /// ``` /// /// The solution is to build a new identifier token with the correct value. As /// this is such a common case, the [`format_ident!`] macro provides a /// convenient utility for doing so correctly. /// /// ``` /// # use proc_macro2::{Ident, Span}; /// # use quote::{format_ident, quote}; /// # /// # let ident = Ident::new("i", Span::call_site()); /// # /// let varname = format_ident!("_{}", ident); /// quote! { /// let mut #varname = 0; /// } /// # ; /// ``` /// /// Alternatively, the APIs provided by Syn and proc-macro2 can be used to /// directly build the identifier. This is roughly equivalent to the above, but /// will not handle `ident` being a raw identifier. /// /// ``` /// # use proc_macro2::{self as syn, Span}; /// # use quote::quote; /// # /// # let ident = syn::Ident::new("i", Span::call_site()); /// # /// let concatenated = format!("_{}", ident); /// let varname = syn::Ident::new(&concatenated, ident.span()); /// quote! { /// let mut #varname = 0; /// } /// # ; /// ``` /// ///


/// /// ### Making method calls /// /// Let's say our macro requires some type specified in the macro input to have /// a constructor called `new`. We have the type in a variable called /// `field_type` of type `syn::Type` and want to invoke the constructor. /// /// ``` /// # use quote::quote; /// # /// # let field_type = quote!(...); /// # /// // incorrect /// quote! { /// let value = #field_type::new(); /// } /// # ; /// ``` /// /// This works only sometimes. If `field_type` is `String`, the expanded code /// contains `String::new()` which is fine. But if `field_type` is something /// like `Vec` then the expanded code is `Vec::new()` which is invalid /// syntax. Ordinarily in handwritten Rust we would write `Vec::::new()` /// but for macros often the following is more convenient. /// /// ``` /// # use quote::quote; /// # /// # let field_type = quote!(...); /// # /// quote! { /// let value = <#field_type>::new(); /// } /// # ; /// ``` /// /// This expands to `>::new()` which behaves correctly. /// /// A similar pattern is appropriate for trait methods. /// /// ``` /// # use quote::quote; /// # /// # let field_type = quote!(...); /// # /// quote! { /// let value = <#field_type as core::default::Default>::default(); /// } /// # ; /// ``` /// ///


/// /// ### Interpolating text inside of doc comments /// /// Neither doc comments nor string literals get interpolation behavior in /// quote: /// /// ```compile_fail /// quote! { /// /// try to interpolate: #ident /// /// /// /// ... /// } /// ``` /// /// ```compile_fail /// quote! { /// #[doc = "try to interpolate: #ident"] /// } /// ``` /// /// Instead the best way to build doc comments that involve variables is by /// formatting the doc string literal outside of quote. /// /// ```rust /// # use proc_macro2::{Ident, Span}; /// # use quote::quote; /// # /// # const IGNORE: &str = stringify! { /// let msg = format!(...); /// # }; /// # /// # let ident = Ident::new("var", Span::call_site()); /// # let msg = format!("try to interpolate: {}", ident); /// quote! { /// #[doc = #msg] /// /// /// /// ... /// } /// # ; /// ``` /// ///


/// /// ### Indexing into a tuple struct /// /// When interpolating indices of a tuple or tuple struct, we need them not to /// appears suffixed as integer literals by interpolating them as [`syn::Index`] /// instead. /// /// [`syn::Index`]: https://docs.rs/syn/1.0/syn/struct.Index.html /// /// ```compile_fail /// let i = 0usize..self.fields.len(); /// /// // expands to 0 + self.0usize.heap_size() + self.1usize.heap_size() + ... /// // which is not valid syntax /// quote! { /// 0 #( + self.#i.heap_size() )* /// } /// ``` /// /// ``` /// # use proc_macro2::{Ident, TokenStream}; /// # use quote::quote; /// # /// # mod syn { /// # use proc_macro2::{Literal, TokenStream}; /// # use quote::{ToTokens, TokenStreamExt}; /// # /// # pub struct Index(usize); /// # /// # impl From for Index { /// # fn from(i: usize) -> Self { /// # Index(i) /// # } /// # } /// # /// # impl ToTokens for Index { /// # fn to_tokens(&self, tokens: &mut TokenStream) { /// # tokens.append(Literal::usize_unsuffixed(self.0)); /// # } /// # } /// # } /// # /// # struct Struct { /// # fields: Vec, /// # } /// # /// # impl Struct { /// # fn example(&self) -> TokenStream { /// let i = (0..self.fields.len()).map(syn::Index::from); /// /// // expands to 0 + self.0.heap_size() + self.1.heap_size() + ... /// quote! { /// 0 #( + self.#i.heap_size() )* /// } /// # } /// # } /// ``` #[cfg(doc)] #[macro_export] macro_rules! quote { ($($tt:tt)*) => { ... }; } #[cfg(not(doc))] #[macro_export] macro_rules! quote { () => { $crate::__private::TokenStream::new() }; // Special case rule for a single tt, for performance. ($tt:tt) => {{ let mut _s = $crate::__private::TokenStream::new(); $crate::quote_token!{$tt _s} _s }}; // Special case rules for two tts, for performance. (# $var:ident) => {{ let mut _s = $crate::__private::TokenStream::new(); $crate::ToTokens::to_tokens(&$var, &mut _s); _s }}; ($tt1:tt $tt2:tt) => {{ let mut _s = $crate::__private::TokenStream::new(); $crate::quote_token!{$tt1 _s} $crate::quote_token!{$tt2 _s} _s }}; // Rule for any other number of tokens. ($($tt:tt)*) => {{ let mut _s = $crate::__private::TokenStream::new(); $crate::quote_each_token!{_s $($tt)*} _s }}; } /// Same as `quote!`, but applies a given span to all tokens originating within /// the macro invocation. /// ///
/// /// # Syntax /// /// A span expression of type [`Span`], followed by `=>`, followed by the tokens /// to quote. The span expression should be brief — use a variable for /// anything more than a few characters. There should be no space before the /// `=>` token. /// /// [`Span`]: https://docs.rs/proc-macro2/1.0/proc_macro2/struct.Span.html /// /// ``` /// # use proc_macro2::Span; /// # use quote::quote_spanned; /// # /// # const IGNORE_TOKENS: &'static str = stringify! { /// let span = /* ... */; /// # }; /// # let span = Span::call_site(); /// # let init = 0; /// /// // On one line, use parentheses. /// let tokens = quote_spanned!(span=> Box::into_raw(Box::new(#init))); /// /// // On multiple lines, place the span at the top and use braces. /// let tokens = quote_spanned! {span=> /// Box::into_raw(Box::new(#init)) /// }; /// ``` /// /// The lack of space before the `=>` should look jarring to Rust programmers /// and this is intentional. The formatting is designed to be visibly /// off-balance and draw the eye a particular way, due to the span expression /// being evaluated in the context of the procedural macro and the remaining /// tokens being evaluated in the generated code. /// ///
/// /// # Hygiene /// /// Any interpolated tokens preserve the `Span` information provided by their /// `ToTokens` implementation. Tokens that originate within the `quote_spanned!` /// invocation are spanned with the given span argument. /// ///
/// /// # Example /// /// The following procedural macro code uses `quote_spanned!` to assert that a /// particular Rust type implements the [`Sync`] trait so that references can be /// safely shared between threads. /// /// [`Sync`]: https://doc.rust-lang.org/std/marker/trait.Sync.html /// /// ``` /// # use quote::{quote_spanned, TokenStreamExt, ToTokens}; /// # use proc_macro2::{Span, TokenStream}; /// # /// # struct Type; /// # /// # impl Type { /// # fn span(&self) -> Span { /// # Span::call_site() /// # } /// # } /// # /// # impl ToTokens for Type { /// # fn to_tokens(&self, _tokens: &mut TokenStream) {} /// # } /// # /// # let ty = Type; /// # let call_site = Span::call_site(); /// # /// let ty_span = ty.span(); /// let assert_sync = quote_spanned! {ty_span=> /// struct _AssertSync where #ty: Sync; /// }; /// ``` /// /// If the assertion fails, the user will see an error like the following. The /// input span of their type is highlighted in the error. /// /// ```text /// error[E0277]: the trait bound `*const (): std::marker::Sync` is not satisfied /// --> src/main.rs:10:21 /// | /// 10 | static ref PTR: *const () = &(); /// | ^^^^^^^^^ `*const ()` cannot be shared between threads safely /// ``` /// /// In this example it is important for the where-clause to be spanned with the /// line/column information of the user's input type so that error messages are /// placed appropriately by the compiler. #[cfg(doc)] #[macro_export] macro_rules! quote_spanned { ($span:expr=> $($tt:tt)*) => { ... }; } #[cfg(not(doc))] #[macro_export] macro_rules! quote_spanned { ($span:expr=>) => {{ let _: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); $crate::__private::TokenStream::new() }}; // Special case rule for a single tt, for performance. ($span:expr=> $tt:tt) => {{ let mut _s = $crate::__private::TokenStream::new(); let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); $crate::quote_token_spanned!{$tt _s _span} _s }}; // Special case rules for two tts, for performance. ($span:expr=> # $var:ident) => {{ let mut _s = $crate::__private::TokenStream::new(); let _: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); $crate::ToTokens::to_tokens(&$var, &mut _s); _s }}; ($span:expr=> $tt1:tt $tt2:tt) => {{ let mut _s = $crate::__private::TokenStream::new(); let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); $crate::quote_token_spanned!{$tt1 _s _span} $crate::quote_token_spanned!{$tt2 _s _span} _s }}; // Rule for any other number of tokens. ($span:expr=> $($tt:tt)*) => {{ let mut _s = $crate::__private::TokenStream::new(); let _span: $crate::__private::Span = $crate::__private::get_span($span).__into_span(); $crate::quote_each_token_spanned!{_s _span $($tt)*} _s }}; } // Extract the names of all #metavariables and pass them to the $call macro. // // in: pounded_var_names!(then!(...) a #b c #( #d )* #e) // out: then!(... b); // then!(... d); // then!(... e); #[macro_export] #[doc(hidden)] macro_rules! pounded_var_names { ($call:ident! $extra:tt $($tts:tt)*) => { $crate::pounded_var_names_with_context!{$call! $extra (@ $($tts)*) ($($tts)* @) } }; } #[macro_export] #[doc(hidden)] macro_rules! pounded_var_names_with_context { ($call:ident! $extra:tt ($($b1:tt)*) ($($curr:tt)*)) => { $( $crate::pounded_var_with_context!{$call! $extra $b1 $curr} )* }; } #[macro_export] #[doc(hidden)] macro_rules! pounded_var_with_context { ($call:ident! $extra:tt $b1:tt ( $($inner:tt)* )) => { $crate::pounded_var_names!{$call! $extra $($inner)*} }; ($call:ident! $extra:tt $b1:tt [ $($inner:tt)* ]) => { $crate::pounded_var_names!{$call! $extra $($inner)*} }; ($call:ident! $extra:tt $b1:tt { $($inner:tt)* }) => { $crate::pounded_var_names!{$call! $extra $($inner)*} }; ($call:ident!($($extra:tt)*) # $var:ident) => { $crate::$call!($($extra)* $var); }; ($call:ident! $extra:tt $b1:tt $curr:tt) => {}; } #[macro_export] #[doc(hidden)] macro_rules! quote_bind_into_iter { ($has_iter:ident $var:ident) => { // `mut` may be unused if $var occurs multiple times in the list. #[allow(unused_mut)] let (mut $var, i) = $var.quote_into_iter(); let $has_iter = $has_iter | i; }; } #[macro_export] #[doc(hidden)] macro_rules! quote_bind_next_or_break { ($var:ident) => { let $var = match $var.next() { Some(_x) => $crate::__private::RepInterp(_x), None => break, }; }; } // The obvious way to write this macro is as a tt muncher. This implementation // does something more complex for two reasons. // // - With a tt muncher it's easy to hit Rust's built-in recursion_limit, which // this implementation avoids because it isn't tail recursive. // // - Compile times for a tt muncher are quadratic relative to the length of // the input. This implementation is linear, so it will be faster // (potentially much faster) for big inputs. However, the constant factors // of this implementation are higher than that of a tt muncher, so it is // somewhat slower than a tt muncher if there are many invocations with // short inputs. // // An invocation like this: // // quote_each_token!(_s a b c d e f g h i j); // // expands to this: // // quote_tokens_with_context!(_s // (@ @ @ @ @ @ a b c d e f g h i j) // (@ @ @ @ @ a b c d e f g h i j @) // (@ @ @ @ a b c d e f g h i j @ @) // (@ @ @ (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) @ @ @) // (@ @ a b c d e f g h i j @ @ @ @) // (@ a b c d e f g h i j @ @ @ @ @) // (a b c d e f g h i j @ @ @ @ @ @) // ); // // which gets transposed and expanded to this: // // quote_token_with_context!(_s @ @ @ @ @ @ a); // quote_token_with_context!(_s @ @ @ @ @ a b); // quote_token_with_context!(_s @ @ @ @ a b c); // quote_token_with_context!(_s @ @ @ (a) b c d); // quote_token_with_context!(_s @ @ a (b) c d e); // quote_token_with_context!(_s @ a b (c) d e f); // quote_token_with_context!(_s a b c (d) e f g); // quote_token_with_context!(_s b c d (e) f g h); // quote_token_with_context!(_s c d e (f) g h i); // quote_token_with_context!(_s d e f (g) h i j); // quote_token_with_context!(_s e f g (h) i j @); // quote_token_with_context!(_s f g h (i) j @ @); // quote_token_with_context!(_s g h i (j) @ @ @); // quote_token_with_context!(_s h i j @ @ @ @); // quote_token_with_context!(_s i j @ @ @ @ @); // quote_token_with_context!(_s j @ @ @ @ @ @); // // Without having used muncher-style recursion, we get one invocation of // quote_token_with_context for each original tt, with three tts of context on // either side. This is enough for the longest possible interpolation form (a // repetition with separator, as in `# (#var) , *`) to be fully represented with // the first or last tt in the middle. // // The middle tt (surrounded by parentheses) is the tt being processed. // // - When it is a `#`, quote_token_with_context can do an interpolation. The // interpolation kind will depend on the three subsequent tts. // // - When it is within a later part of an interpolation, it can be ignored // because the interpolation has already been done. // // - When it is not part of an interpolation it can be pushed as a single // token into the output. // // - When the middle token is an unparenthesized `@`, that call is one of the // first 3 or last 3 calls of quote_token_with_context and does not // correspond to one of the original input tokens, so turns into nothing. #[macro_export] #[doc(hidden)] macro_rules! quote_each_token { ($tokens:ident $($tts:tt)*) => { $crate::quote_tokens_with_context!{$tokens (@ @ @ @ @ @ $($tts)*) (@ @ @ @ @ $($tts)* @) (@ @ @ @ $($tts)* @ @) (@ @ @ $(($tts))* @ @ @) (@ @ $($tts)* @ @ @ @) (@ $($tts)* @ @ @ @ @) ($($tts)* @ @ @ @ @ @) } }; } // See the explanation on quote_each_token. #[macro_export] #[doc(hidden)] macro_rules! quote_each_token_spanned { ($tokens:ident $span:ident $($tts:tt)*) => { $crate::quote_tokens_with_context_spanned!{$tokens $span (@ @ @ @ @ @ $($tts)*) (@ @ @ @ @ $($tts)* @) (@ @ @ @ $($tts)* @ @) (@ @ @ $(($tts))* @ @ @) (@ @ $($tts)* @ @ @ @) (@ $($tts)* @ @ @ @ @) ($($tts)* @ @ @ @ @ @) } }; } // See the explanation on quote_each_token. #[macro_export] #[doc(hidden)] macro_rules! quote_tokens_with_context { ($tokens:ident ($($b3:tt)*) ($($b2:tt)*) ($($b1:tt)*) ($($curr:tt)*) ($($a1:tt)*) ($($a2:tt)*) ($($a3:tt)*) ) => { $( $crate::quote_token_with_context!{$tokens $b3 $b2 $b1 $curr $a1 $a2 $a3} )* }; } // See the explanation on quote_each_token. #[macro_export] #[doc(hidden)] macro_rules! quote_tokens_with_context_spanned { ($tokens:ident $span:ident ($($b3:tt)*) ($($b2:tt)*) ($($b1:tt)*) ($($curr:tt)*) ($($a1:tt)*) ($($a2:tt)*) ($($a3:tt)*) ) => { $( $crate::quote_token_with_context_spanned!{$tokens $span $b3 $b2 $b1 $curr $a1 $a2 $a3} )* }; } // See the explanation on quote_each_token. #[macro_export] #[doc(hidden)] macro_rules! quote_token_with_context { // Unparenthesized `@` indicates this call does not correspond to one of the // original input tokens. Ignore it. ($tokens:ident $b3:tt $b2:tt $b1:tt @ $a1:tt $a2:tt $a3:tt) => {}; // A repetition with no separator. ($tokens:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) * $a3:tt) => {{ use $crate::__private::ext::*; let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} let _: $crate::__private::HasIterator = has_iter; // This is `while true` instead of `loop` because if there are no // iterators used inside of this repetition then the body would not // contain any `break`, so the compiler would emit unreachable code // warnings on anything below the loop. We use has_iter to detect and // fail to compile when there are no iterators, so here we just work // around the unneeded extra warning. while true { $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} $crate::quote_each_token!{$tokens $($inner)*} } }}; // ... and one step later. ($tokens:ident $b3:tt $b2:tt # (( $($inner:tt)* )) * $a2:tt $a3:tt) => {}; // ... and one step later. ($tokens:ident $b3:tt # ( $($inner:tt)* ) (*) $a1:tt $a2:tt $a3:tt) => {}; // A repetition with separator. ($tokens:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) $sep:tt *) => {{ use $crate::__private::ext::*; let mut _i = 0usize; let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} let _: $crate::__private::HasIterator = has_iter; while true { $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} if _i > 0 { $crate::quote_token!{$sep $tokens} } _i += 1; $crate::quote_each_token!{$tokens $($inner)*} } }}; // ... and one step later. ($tokens:ident $b3:tt $b2:tt # (( $($inner:tt)* )) $sep:tt * $a3:tt) => {}; // ... and one step later. ($tokens:ident $b3:tt # ( $($inner:tt)* ) ($sep:tt) * $a2:tt $a3:tt) => {}; // (A special case for `#(var)**`, where the first `*` is treated as the // repetition symbol and the second `*` is treated as an ordinary token.) ($tokens:ident # ( $($inner:tt)* ) * (*) $a1:tt $a2:tt $a3:tt) => { // https://github.com/dtolnay/quote/issues/130 $crate::quote_token!{* $tokens} }; // ... and one step later. ($tokens:ident # ( $($inner:tt)* ) $sep:tt (*) $a1:tt $a2:tt $a3:tt) => {}; // A non-repetition interpolation. ($tokens:ident $b3:tt $b2:tt $b1:tt (#) $var:ident $a2:tt $a3:tt) => { $crate::ToTokens::to_tokens(&$var, &mut $tokens); }; // ... and one step later. ($tokens:ident $b3:tt $b2:tt # ($var:ident) $a1:tt $a2:tt $a3:tt) => {}; // An ordinary token, not part of any interpolation. ($tokens:ident $b3:tt $b2:tt $b1:tt ($curr:tt) $a1:tt $a2:tt $a3:tt) => { $crate::quote_token!{$curr $tokens} }; } // See the explanation on quote_each_token, and on the individual rules of // quote_token_with_context. #[macro_export] #[doc(hidden)] macro_rules! quote_token_with_context_spanned { ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt @ $a1:tt $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) * $a3:tt) => {{ use $crate::__private::ext::*; let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} let _: $crate::__private::HasIterator = has_iter; while true { $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} $crate::quote_each_token_spanned!{$tokens $span $($inner)*} } }}; ($tokens:ident $span:ident $b3:tt $b2:tt # (( $($inner:tt)* )) * $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt # ( $($inner:tt)* ) (*) $a1:tt $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) ( $($inner:tt)* ) $sep:tt *) => {{ use $crate::__private::ext::*; let mut _i = 0usize; let has_iter = $crate::__private::ThereIsNoIteratorInRepetition; $crate::pounded_var_names!{quote_bind_into_iter!(has_iter) () $($inner)*} let _: $crate::__private::HasIterator = has_iter; while true { $crate::pounded_var_names!{quote_bind_next_or_break!() () $($inner)*} if _i > 0 { $crate::quote_token_spanned!{$sep $tokens $span} } _i += 1; $crate::quote_each_token_spanned!{$tokens $span $($inner)*} } }}; ($tokens:ident $span:ident $b3:tt $b2:tt # (( $($inner:tt)* )) $sep:tt * $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt # ( $($inner:tt)* ) ($sep:tt) * $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident # ( $($inner:tt)* ) * (*) $a1:tt $a2:tt $a3:tt) => { // https://github.com/dtolnay/quote/issues/130 $crate::quote_token_spanned!{* $tokens $span} }; ($tokens:ident $span:ident # ( $($inner:tt)* ) $sep:tt (*) $a1:tt $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt (#) $var:ident $a2:tt $a3:tt) => { $crate::ToTokens::to_tokens(&$var, &mut $tokens); }; ($tokens:ident $span:ident $b3:tt $b2:tt # ($var:ident) $a1:tt $a2:tt $a3:tt) => {}; ($tokens:ident $span:ident $b3:tt $b2:tt $b1:tt ($curr:tt) $a1:tt $a2:tt $a3:tt) => { $crate::quote_token_spanned!{$curr $tokens $span} }; } // These rules are ordered by approximate token frequency, at least for the // first 10 or so, to improve compile times. Having `ident` first is by far the // most important because it's typically 2-3x more common than the next most // common token. // // Separately, we put the token being matched in the very front so that failing // rules may fail to match as quickly as possible. #[macro_export] #[doc(hidden)] macro_rules! quote_token { ($ident:ident $tokens:ident) => { $crate::__private::push_ident(&mut $tokens, stringify!($ident)); }; (:: $tokens:ident) => { $crate::__private::push_colon2(&mut $tokens); }; (( $($inner:tt)* ) $tokens:ident) => { $crate::__private::push_group( &mut $tokens, $crate::__private::Delimiter::Parenthesis, $crate::quote!($($inner)*), ); }; ([ $($inner:tt)* ] $tokens:ident) => { $crate::__private::push_group( &mut $tokens, $crate::__private::Delimiter::Bracket, $crate::quote!($($inner)*), ); }; ({ $($inner:tt)* } $tokens:ident) => { $crate::__private::push_group( &mut $tokens, $crate::__private::Delimiter::Brace, $crate::quote!($($inner)*), ); }; (# $tokens:ident) => { $crate::__private::push_pound(&mut $tokens); }; (, $tokens:ident) => { $crate::__private::push_comma(&mut $tokens); }; (. $tokens:ident) => { $crate::__private::push_dot(&mut $tokens); }; (; $tokens:ident) => { $crate::__private::push_semi(&mut $tokens); }; (: $tokens:ident) => { $crate::__private::push_colon(&mut $tokens); }; (+ $tokens:ident) => { $crate::__private::push_add(&mut $tokens); }; (+= $tokens:ident) => { $crate::__private::push_add_eq(&mut $tokens); }; (& $tokens:ident) => { $crate::__private::push_and(&mut $tokens); }; (&& $tokens:ident) => { $crate::__private::push_and_and(&mut $tokens); }; (&= $tokens:ident) => { $crate::__private::push_and_eq(&mut $tokens); }; (@ $tokens:ident) => { $crate::__private::push_at(&mut $tokens); }; (! $tokens:ident) => { $crate::__private::push_bang(&mut $tokens); }; (^ $tokens:ident) => { $crate::__private::push_caret(&mut $tokens); }; (^= $tokens:ident) => { $crate::__private::push_caret_eq(&mut $tokens); }; (/ $tokens:ident) => { $crate::__private::push_div(&mut $tokens); }; (/= $tokens:ident) => { $crate::__private::push_div_eq(&mut $tokens); }; (.. $tokens:ident) => { $crate::__private::push_dot2(&mut $tokens); }; (... $tokens:ident) => { $crate::__private::push_dot3(&mut $tokens); }; (..= $tokens:ident) => { $crate::__private::push_dot_dot_eq(&mut $tokens); }; (= $tokens:ident) => { $crate::__private::push_eq(&mut $tokens); }; (== $tokens:ident) => { $crate::__private::push_eq_eq(&mut $tokens); }; (>= $tokens:ident) => { $crate::__private::push_ge(&mut $tokens); }; (> $tokens:ident) => { $crate::__private::push_gt(&mut $tokens); }; (<= $tokens:ident) => { $crate::__private::push_le(&mut $tokens); }; (< $tokens:ident) => { $crate::__private::push_lt(&mut $tokens); }; (*= $tokens:ident) => { $crate::__private::push_mul_eq(&mut $tokens); }; (!= $tokens:ident) => { $crate::__private::push_ne(&mut $tokens); }; (| $tokens:ident) => { $crate::__private::push_or(&mut $tokens); }; (|= $tokens:ident) => { $crate::__private::push_or_eq(&mut $tokens); }; (|| $tokens:ident) => { $crate::__private::push_or_or(&mut $tokens); }; (? $tokens:ident) => { $crate::__private::push_question(&mut $tokens); }; (-> $tokens:ident) => { $crate::__private::push_rarrow(&mut $tokens); }; (<- $tokens:ident) => { $crate::__private::push_larrow(&mut $tokens); }; (% $tokens:ident) => { $crate::__private::push_rem(&mut $tokens); }; (%= $tokens:ident) => { $crate::__private::push_rem_eq(&mut $tokens); }; (=> $tokens:ident) => { $crate::__private::push_fat_arrow(&mut $tokens); }; (<< $tokens:ident) => { $crate::__private::push_shl(&mut $tokens); }; (<<= $tokens:ident) => { $crate::__private::push_shl_eq(&mut $tokens); }; (>> $tokens:ident) => { $crate::__private::push_shr(&mut $tokens); }; (>>= $tokens:ident) => { $crate::__private::push_shr_eq(&mut $tokens); }; (* $tokens:ident) => { $crate::__private::push_star(&mut $tokens); }; (- $tokens:ident) => { $crate::__private::push_sub(&mut $tokens); }; (-= $tokens:ident) => { $crate::__private::push_sub_eq(&mut $tokens); }; ($lifetime:lifetime $tokens:ident) => { $crate::__private::push_lifetime(&mut $tokens, stringify!($lifetime)); }; (_ $tokens:ident) => { $crate::__private::push_underscore(&mut $tokens); }; ($other:tt $tokens:ident) => { $crate::__private::parse(&mut $tokens, stringify!($other)); }; } // See the comment above `quote_token!` about the rule ordering. #[macro_export] #[doc(hidden)] macro_rules! quote_token_spanned { ($ident:ident $tokens:ident $span:ident) => { $crate::__private::push_ident_spanned(&mut $tokens, $span, stringify!($ident)); }; (:: $tokens:ident $span:ident) => { $crate::__private::push_colon2_spanned(&mut $tokens, $span); }; (( $($inner:tt)* ) $tokens:ident $span:ident) => { $crate::__private::push_group_spanned( &mut $tokens, $span, $crate::__private::Delimiter::Parenthesis, $crate::quote_spanned!($span=> $($inner)*), ); }; ([ $($inner:tt)* ] $tokens:ident $span:ident) => { $crate::__private::push_group_spanned( &mut $tokens, $span, $crate::__private::Delimiter::Bracket, $crate::quote_spanned!($span=> $($inner)*), ); }; ({ $($inner:tt)* } $tokens:ident $span:ident) => { $crate::__private::push_group_spanned( &mut $tokens, $span, $crate::__private::Delimiter::Brace, $crate::quote_spanned!($span=> $($inner)*), ); }; (# $tokens:ident $span:ident) => { $crate::__private::push_pound_spanned(&mut $tokens, $span); }; (, $tokens:ident $span:ident) => { $crate::__private::push_comma_spanned(&mut $tokens, $span); }; (. $tokens:ident $span:ident) => { $crate::__private::push_dot_spanned(&mut $tokens, $span); }; (; $tokens:ident $span:ident) => { $crate::__private::push_semi_spanned(&mut $tokens, $span); }; (: $tokens:ident $span:ident) => { $crate::__private::push_colon_spanned(&mut $tokens, $span); }; (+ $tokens:ident $span:ident) => { $crate::__private::push_add_spanned(&mut $tokens, $span); }; (+= $tokens:ident $span:ident) => { $crate::__private::push_add_eq_spanned(&mut $tokens, $span); }; (& $tokens:ident $span:ident) => { $crate::__private::push_and_spanned(&mut $tokens, $span); }; (&& $tokens:ident $span:ident) => { $crate::__private::push_and_and_spanned(&mut $tokens, $span); }; (&= $tokens:ident $span:ident) => { $crate::__private::push_and_eq_spanned(&mut $tokens, $span); }; (@ $tokens:ident $span:ident) => { $crate::__private::push_at_spanned(&mut $tokens, $span); }; (! $tokens:ident $span:ident) => { $crate::__private::push_bang_spanned(&mut $tokens, $span); }; (^ $tokens:ident $span:ident) => { $crate::__private::push_caret_spanned(&mut $tokens, $span); }; (^= $tokens:ident $span:ident) => { $crate::__private::push_caret_eq_spanned(&mut $tokens, $span); }; (/ $tokens:ident $span:ident) => { $crate::__private::push_div_spanned(&mut $tokens, $span); }; (/= $tokens:ident $span:ident) => { $crate::__private::push_div_eq_spanned(&mut $tokens, $span); }; (.. $tokens:ident $span:ident) => { $crate::__private::push_dot2_spanned(&mut $tokens, $span); }; (... $tokens:ident $span:ident) => { $crate::__private::push_dot3_spanned(&mut $tokens, $span); }; (..= $tokens:ident $span:ident) => { $crate::__private::push_dot_dot_eq_spanned(&mut $tokens, $span); }; (= $tokens:ident $span:ident) => { $crate::__private::push_eq_spanned(&mut $tokens, $span); }; (== $tokens:ident $span:ident) => { $crate::__private::push_eq_eq_spanned(&mut $tokens, $span); }; (>= $tokens:ident $span:ident) => { $crate::__private::push_ge_spanned(&mut $tokens, $span); }; (> $tokens:ident $span:ident) => { $crate::__private::push_gt_spanned(&mut $tokens, $span); }; (<= $tokens:ident $span:ident) => { $crate::__private::push_le_spanned(&mut $tokens, $span); }; (< $tokens:ident $span:ident) => { $crate::__private::push_lt_spanned(&mut $tokens, $span); }; (*= $tokens:ident $span:ident) => { $crate::__private::push_mul_eq_spanned(&mut $tokens, $span); }; (!= $tokens:ident $span:ident) => { $crate::__private::push_ne_spanned(&mut $tokens, $span); }; (| $tokens:ident $span:ident) => { $crate::__private::push_or_spanned(&mut $tokens, $span); }; (|= $tokens:ident $span:ident) => { $crate::__private::push_or_eq_spanned(&mut $tokens, $span); }; (|| $tokens:ident $span:ident) => { $crate::__private::push_or_or_spanned(&mut $tokens, $span); }; (? $tokens:ident $span:ident) => { $crate::__private::push_question_spanned(&mut $tokens, $span); }; (-> $tokens:ident $span:ident) => { $crate::__private::push_rarrow_spanned(&mut $tokens, $span); }; (<- $tokens:ident $span:ident) => { $crate::__private::push_larrow_spanned(&mut $tokens, $span); }; (% $tokens:ident $span:ident) => { $crate::__private::push_rem_spanned(&mut $tokens, $span); }; (%= $tokens:ident $span:ident) => { $crate::__private::push_rem_eq_spanned(&mut $tokens, $span); }; (=> $tokens:ident $span:ident) => { $crate::__private::push_fat_arrow_spanned(&mut $tokens, $span); }; (<< $tokens:ident $span:ident) => { $crate::__private::push_shl_spanned(&mut $tokens, $span); }; (<<= $tokens:ident $span:ident) => { $crate::__private::push_shl_eq_spanned(&mut $tokens, $span); }; (>> $tokens:ident $span:ident) => { $crate::__private::push_shr_spanned(&mut $tokens, $span); }; (>>= $tokens:ident $span:ident) => { $crate::__private::push_shr_eq_spanned(&mut $tokens, $span); }; (* $tokens:ident $span:ident) => { $crate::__private::push_star_spanned(&mut $tokens, $span); }; (- $tokens:ident $span:ident) => { $crate::__private::push_sub_spanned(&mut $tokens, $span); }; (-= $tokens:ident $span:ident) => { $crate::__private::push_sub_eq_spanned(&mut $tokens, $span); }; ($lifetime:lifetime $tokens:ident $span:ident) => { $crate::__private::push_lifetime_spanned(&mut $tokens, $span, stringify!($lifetime)); }; (_ $tokens:ident $span:ident) => { $crate::__private::push_underscore_spanned(&mut $tokens, $span); }; ($other:tt $tokens:ident $span:ident) => { $crate::__private::parse_spanned(&mut $tokens, $span, stringify!($other)); }; }