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Diffstat (limited to 'syn/src/token.rs')
| -rw-r--r-- | syn/src/token.rs | 956 |
1 files changed, 0 insertions, 956 deletions
diff --git a/syn/src/token.rs b/syn/src/token.rs deleted file mode 100644 index a9f787a..0000000 --- a/syn/src/token.rs +++ /dev/null @@ -1,956 +0,0 @@ -//! Tokens representing Rust punctuation, keywords, and delimiters. -//! -//! The type names in this module can be difficult to keep straight, so we -//! prefer to use the [`Token!`] macro instead. This is a type-macro that -//! expands to the token type of the given token. -//! -//! [`Token!`]: ../macro.Token.html -//! -//! # Example -//! -//! The [`ItemStatic`] syntax tree node is defined like this. -//! -//! [`ItemStatic`]: ../struct.ItemStatic.html -//! -//! ``` -//! # use syn::{Attribute, Expr, Ident, Token, Type, Visibility}; -//! # -//! pub struct ItemStatic { -//! pub attrs: Vec<Attribute>, -//! pub vis: Visibility, -//! pub static_token: Token![static], -//! pub mutability: Option<Token![mut]>, -//! pub ident: Ident, -//! pub colon_token: Token![:], -//! pub ty: Box<Type>, -//! pub eq_token: Token![=], -//! pub expr: Box<Expr>, -//! pub semi_token: Token![;], -//! } -//! ``` -//! -//! # Parsing -//! -//! Keywords and punctuation can be parsed through the [`ParseStream::parse`] -//! method. Delimiter tokens are parsed using the [`parenthesized!`], -//! [`bracketed!`] and [`braced!`] macros. -//! -//! [`ParseStream::parse`]: ../parse/struct.ParseBuffer.html#method.parse -//! [`parenthesized!`]: ../macro.parenthesized.html -//! [`bracketed!`]: ../macro.bracketed.html -//! [`braced!`]: ../macro.braced.html -//! -//! ``` -//! use syn::{Attribute, Result}; -//! use syn::parse::{Parse, ParseStream}; -//! # -//! # enum ItemStatic {} -//! -//! // Parse the ItemStatic struct shown above. -//! impl Parse for ItemStatic { -//! fn parse(input: ParseStream) -> Result<Self> { -//! # use syn::ItemStatic; -//! # fn parse(input: ParseStream) -> Result<ItemStatic> { -//! Ok(ItemStatic { -//! attrs: input.call(Attribute::parse_outer)?, -//! vis: input.parse()?, -//! static_token: input.parse()?, -//! mutability: input.parse()?, -//! ident: input.parse()?, -//! colon_token: input.parse()?, -//! ty: input.parse()?, -//! eq_token: input.parse()?, -//! expr: input.parse()?, -//! semi_token: input.parse()?, -//! }) -//! # } -//! # unimplemented!() -//! } -//! } -//! ``` -//! -//! # Other operations -//! -//! Every keyword and punctuation token supports the following operations. -//! -//! - [Peeking] — `input.peek(Token![...])` -//! -//! - [Parsing] — `input.parse::<Token![...]>()?` -//! -//! - [Printing] — `quote!( ... #the_token ... )` -//! -//! - Construction from a [`Span`] — `let the_token = Token` -//! -//! - Field access to its span — `let sp = the_token.span` -//! -//! [Peeking]: ../parse/struct.ParseBuffer.html#method.peek -//! [Parsing]: ../parse/struct.ParseBuffer.html#method.parse -//! [Printing]: https://docs.rs/quote/1.0/quote/trait.ToTokens.html -//! [`Span`]: https://docs.rs/proc-macro2/1.0/proc_macro2/struct.Span.html - -use std; -#[cfg(feature = "extra-traits")] -use std::cmp; -#[cfg(feature = "extra-traits")] -use std::fmt::{self, Debug}; -#[cfg(feature = "extra-traits")] -use std::hash::{Hash, Hasher}; -use std::ops::{Deref, DerefMut}; - -#[cfg(feature = "parsing")] -use proc_macro2::Delimiter; -#[cfg(any(feature = "parsing", feature = "printing"))] -use proc_macro2::Ident; -use proc_macro2::Span; -#[cfg(feature = "printing")] -use proc_macro2::TokenStream; -#[cfg(feature = "printing")] -use quote::{ToTokens, TokenStreamExt}; - -use self::private::WithSpan; -#[cfg(feature = "parsing")] -use crate::buffer::Cursor; -#[cfg(feature = "parsing")] -use crate::error::Result; -#[cfg(any(feature = "full", feature = "derive"))] -#[cfg(feature = "parsing")] -use crate::lifetime::Lifetime; -#[cfg(any(feature = "full", feature = "derive"))] -#[cfg(feature = "parsing")] -use crate::lit::{Lit, LitBool, LitByte, LitByteStr, LitChar, LitFloat, LitInt, LitStr}; -#[cfg(feature = "parsing")] -use crate::lookahead; -#[cfg(feature = "parsing")] -use crate::parse::{Parse, ParseStream}; -use crate::span::IntoSpans; - -/// Marker trait for types that represent single tokens. -/// -/// This trait is sealed and cannot be implemented for types outside of Syn. -#[cfg(feature = "parsing")] -pub trait Token: private::Sealed { - // Not public API. - #[doc(hidden)] - fn peek(cursor: Cursor) -> bool; - - // Not public API. - #[doc(hidden)] - fn display() -> &'static str; -} - -mod private { - use proc_macro2::Span; - - #[cfg(feature = "parsing")] - pub trait Sealed {} - - /// Support writing `token.span` rather than `token.spans[0]` on tokens that - /// hold a single span. - #[repr(C)] - pub struct WithSpan { - pub span: Span, - } -} - -#[cfg(feature = "parsing")] -impl private::Sealed for Ident {} - -#[cfg(any(feature = "full", feature = "derive"))] -#[cfg(feature = "parsing")] -fn peek_impl(cursor: Cursor, peek: fn(ParseStream) -> bool) -> bool { - use crate::parse::Unexpected; - use std::cell::Cell; - use std::rc::Rc; - - let scope = Span::call_site(); - let unexpected = Rc::new(Cell::new(Unexpected::None)); - let buffer = crate::parse::new_parse_buffer(scope, cursor, unexpected); - peek(&buffer) -} - -#[cfg(any(feature = "full", feature = "derive"))] -macro_rules! impl_token { - ($name:ident $display:expr) => { - #[cfg(feature = "parsing")] - impl Token for $name { - fn peek(cursor: Cursor) -> bool { - fn peek(input: ParseStream) -> bool { - <$name as Parse>::parse(input).is_ok() - } - peek_impl(cursor, peek) - } - - fn display() -> &'static str { - $display - } - } - - #[cfg(feature = "parsing")] - impl private::Sealed for $name {} - }; -} - -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(Lifetime "lifetime"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(Lit "literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitStr "string literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitByteStr "byte string literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitByte "byte literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitChar "character literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitInt "integer literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitFloat "floating point literal"); -#[cfg(any(feature = "full", feature = "derive"))] -impl_token!(LitBool "boolean literal"); - -// Not public API. -#[doc(hidden)] -#[cfg(feature = "parsing")] -pub trait CustomToken { - fn peek(cursor: Cursor) -> bool; - fn display() -> &'static str; -} - -#[cfg(feature = "parsing")] -impl<T: CustomToken> private::Sealed for T {} - -#[cfg(feature = "parsing")] -impl<T: CustomToken> Token for T { - fn peek(cursor: Cursor) -> bool { - <Self as CustomToken>::peek(cursor) - } - - fn display() -> &'static str { - <Self as CustomToken>::display() - } -} - -macro_rules! define_keywords { - ($($token:tt pub struct $name:ident #[$doc:meta])*) => { - $( - #[cfg_attr(feature = "clone-impls", derive(Copy, Clone))] - #[$doc] - /// - /// Don't try to remember the name of this type — use the - /// [`Token!`] macro instead. - /// - /// [`Token!`]: crate::token - pub struct $name { - pub span: Span, - } - - #[doc(hidden)] - #[allow(non_snake_case)] - pub fn $name<S: IntoSpans<[Span; 1]>>(span: S) -> $name { - $name { - span: span.into_spans()[0], - } - } - - impl std::default::Default for $name { - fn default() -> Self { - $name { - span: Span::call_site(), - } - } - } - - #[cfg(feature = "extra-traits")] - impl Debug for $name { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - f.write_str(stringify!($name)) - } - } - - #[cfg(feature = "extra-traits")] - impl cmp::Eq for $name {} - - #[cfg(feature = "extra-traits")] - impl PartialEq for $name { - fn eq(&self, _other: &$name) -> bool { - true - } - } - - #[cfg(feature = "extra-traits")] - impl Hash for $name { - fn hash<H: Hasher>(&self, _state: &mut H) {} - } - - #[cfg(feature = "printing")] - impl ToTokens for $name { - fn to_tokens(&self, tokens: &mut TokenStream) { - printing::keyword($token, self.span, tokens); - } - } - - #[cfg(feature = "parsing")] - impl Parse for $name { - fn parse(input: ParseStream) -> Result<Self> { - Ok($name { - span: parsing::keyword(input, $token)?, - }) - } - } - - #[cfg(feature = "parsing")] - impl Token for $name { - fn peek(cursor: Cursor) -> bool { - parsing::peek_keyword(cursor, $token) - } - - fn display() -> &'static str { - concat!("`", $token, "`") - } - } - - #[cfg(feature = "parsing")] - impl private::Sealed for $name {} - )* - }; -} - -macro_rules! impl_deref_if_len_is_1 { - ($name:ident/1) => { - impl Deref for $name { - type Target = WithSpan; - - fn deref(&self) -> &Self::Target { - unsafe { &*(self as *const Self as *const WithSpan) } - } - } - - impl DerefMut for $name { - fn deref_mut(&mut self) -> &mut Self::Target { - unsafe { &mut *(self as *mut Self as *mut WithSpan) } - } - } - }; - - ($name:ident/$len:tt) => {}; -} - -macro_rules! define_punctuation_structs { - ($($token:tt pub struct $name:ident/$len:tt #[$doc:meta])*) => { - $( - #[cfg_attr(feature = "clone-impls", derive(Copy, Clone))] - #[repr(C)] - #[$doc] - /// - /// Don't try to remember the name of this type — use the - /// [`Token!`] macro instead. - /// - /// [`Token!`]: crate::token - pub struct $name { - pub spans: [Span; $len], - } - - #[doc(hidden)] - #[allow(non_snake_case)] - pub fn $name<S: IntoSpans<[Span; $len]>>(spans: S) -> $name { - $name { - spans: spans.into_spans(), - } - } - - impl std::default::Default for $name { - fn default() -> Self { - $name { - spans: [Span::call_site(); $len], - } - } - } - - #[cfg(feature = "extra-traits")] - impl Debug for $name { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - f.write_str(stringify!($name)) - } - } - - #[cfg(feature = "extra-traits")] - impl cmp::Eq for $name {} - - #[cfg(feature = "extra-traits")] - impl PartialEq for $name { - fn eq(&self, _other: &$name) -> bool { - true - } - } - - #[cfg(feature = "extra-traits")] - impl Hash for $name { - fn hash<H: Hasher>(&self, _state: &mut H) {} - } - - impl_deref_if_len_is_1!($name/$len); - )* - }; -} - -macro_rules! define_punctuation { - ($($token:tt pub struct $name:ident/$len:tt #[$doc:meta])*) => { - $( - define_punctuation_structs! { - $token pub struct $name/$len #[$doc] - } - - #[cfg(feature = "printing")] - impl ToTokens for $name { - fn to_tokens(&self, tokens: &mut TokenStream) { - printing::punct($token, &self.spans, tokens); - } - } - - #[cfg(feature = "parsing")] - impl Parse for $name { - fn parse(input: ParseStream) -> Result<Self> { - Ok($name { - spans: parsing::punct(input, $token)?, - }) - } - } - - #[cfg(feature = "parsing")] - impl Token for $name { - fn peek(cursor: Cursor) -> bool { - parsing::peek_punct(cursor, $token) - } - - fn display() -> &'static str { - concat!("`", $token, "`") - } - } - - #[cfg(feature = "parsing")] - impl private::Sealed for $name {} - )* - }; -} - -macro_rules! define_delimiters { - ($($token:tt pub struct $name:ident #[$doc:meta])*) => { - $( - #[cfg_attr(feature = "clone-impls", derive(Copy, Clone))] - #[$doc] - pub struct $name { - pub span: Span, - } - - #[doc(hidden)] - #[allow(non_snake_case)] - pub fn $name<S: IntoSpans<[Span; 1]>>(span: S) -> $name { - $name { - span: span.into_spans()[0], - } - } - - impl std::default::Default for $name { - fn default() -> Self { - $name { - span: Span::call_site(), - } - } - } - - #[cfg(feature = "extra-traits")] - impl Debug for $name { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - f.write_str(stringify!($name)) - } - } - - #[cfg(feature = "extra-traits")] - impl cmp::Eq for $name {} - - #[cfg(feature = "extra-traits")] - impl PartialEq for $name { - fn eq(&self, _other: &$name) -> bool { - true - } - } - - #[cfg(feature = "extra-traits")] - impl Hash for $name { - fn hash<H: Hasher>(&self, _state: &mut H) {} - } - - impl $name { - #[cfg(feature = "printing")] - pub fn surround<F>(&self, tokens: &mut TokenStream, f: F) - where - F: FnOnce(&mut TokenStream), - { - printing::delim($token, self.span, tokens, f); - } - } - - #[cfg(feature = "parsing")] - impl private::Sealed for $name {} - )* - }; -} - -define_punctuation_structs! { - "_" pub struct Underscore/1 /// `_` -} - -#[cfg(feature = "printing")] -impl ToTokens for Underscore { - fn to_tokens(&self, tokens: &mut TokenStream) { - tokens.append(Ident::new("_", self.span)); - } -} - -#[cfg(feature = "parsing")] -impl Parse for Underscore { - fn parse(input: ParseStream) -> Result<Self> { - input.step(|cursor| { - if let Some((ident, rest)) = cursor.ident() { - if ident == "_" { - return Ok((Underscore(ident.span()), rest)); - } - } - if let Some((punct, rest)) = cursor.punct() { - if punct.as_char() == '_' { - return Ok((Underscore(punct.span()), rest)); - } - } - Err(cursor.error("expected `_`")) - }) - } -} - -#[cfg(feature = "parsing")] -impl Token for Underscore { - fn peek(cursor: Cursor) -> bool { - if let Some((ident, _rest)) = cursor.ident() { - return ident == "_"; - } - if let Some((punct, _rest)) = cursor.punct() { - return punct.as_char() == '_'; - } - false - } - - fn display() -> &'static str { - "`_`" - } -} - -#[cfg(feature = "parsing")] -impl private::Sealed for Underscore {} - -#[cfg(feature = "parsing")] -impl Token for Paren { - fn peek(cursor: Cursor) -> bool { - lookahead::is_delimiter(cursor, Delimiter::Parenthesis) - } - - fn display() -> &'static str { - "parentheses" - } -} - -#[cfg(feature = "parsing")] -impl Token for Brace { - fn peek(cursor: Cursor) -> bool { - lookahead::is_delimiter(cursor, Delimiter::Brace) - } - - fn display() -> &'static str { - "curly braces" - } -} - -#[cfg(feature = "parsing")] -impl Token for Bracket { - fn peek(cursor: Cursor) -> bool { - lookahead::is_delimiter(cursor, Delimiter::Bracket) - } - - fn display() -> &'static str { - "square brackets" - } -} - -#[cfg(feature = "parsing")] -impl Token for Group { - fn peek(cursor: Cursor) -> bool { - lookahead::is_delimiter(cursor, Delimiter::None) - } - - fn display() -> &'static str { - "invisible group" - } -} - -define_keywords! { - "abstract" pub struct Abstract /// `abstract` - "as" pub struct As /// `as` - "async" pub struct Async /// `async` - "auto" pub struct Auto /// `auto` - "await" pub struct Await /// `await` - "become" pub struct Become /// `become` - "box" pub struct Box /// `box` - "break" pub struct Break /// `break` - "const" pub struct Const /// `const` - "continue" pub struct Continue /// `continue` - "crate" pub struct Crate /// `crate` - "default" pub struct Default /// `default` - "do" pub struct Do /// `do` - "dyn" pub struct Dyn /// `dyn` - "else" pub struct Else /// `else` - "enum" pub struct Enum /// `enum` - "extern" pub struct Extern /// `extern` - "final" pub struct Final /// `final` - "fn" pub struct Fn /// `fn` - "for" pub struct For /// `for` - "if" pub struct If /// `if` - "impl" pub struct Impl /// `impl` - "in" pub struct In /// `in` - "let" pub struct Let /// `let` - "loop" pub struct Loop /// `loop` - "macro" pub struct Macro /// `macro` - "match" pub struct Match /// `match` - "mod" pub struct Mod /// `mod` - "move" pub struct Move /// `move` - "mut" pub struct Mut /// `mut` - "override" pub struct Override /// `override` - "priv" pub struct Priv /// `priv` - "pub" pub struct Pub /// `pub` - "ref" pub struct Ref /// `ref` - "return" pub struct Return /// `return` - "Self" pub struct SelfType /// `Self` - "self" pub struct SelfValue /// `self` - "static" pub struct Static /// `static` - "struct" pub struct Struct /// `struct` - "super" pub struct Super /// `super` - "trait" pub struct Trait /// `trait` - "try" pub struct Try /// `try` - "type" pub struct Type /// `type` - "typeof" pub struct Typeof /// `typeof` - "union" pub struct Union /// `union` - "unsafe" pub struct Unsafe /// `unsafe` - "unsized" pub struct Unsized /// `unsized` - "use" pub struct Use /// `use` - "virtual" pub struct Virtual /// `virtual` - "where" pub struct Where /// `where` - "while" pub struct While /// `while` - "yield" pub struct Yield /// `yield` -} - -define_punctuation! { - "+" pub struct Add/1 /// `+` - "+=" pub struct AddEq/2 /// `+=` - "&" pub struct And/1 /// `&` - "&&" pub struct AndAnd/2 /// `&&` - "&=" pub struct AndEq/2 /// `&=` - "@" pub struct At/1 /// `@` - "!" pub struct Bang/1 /// `!` - "^" pub struct Caret/1 /// `^` - "^=" pub struct CaretEq/2 /// `^=` - ":" pub struct Colon/1 /// `:` - "::" pub struct Colon2/2 /// `::` - "," pub struct Comma/1 /// `,` - "/" pub struct Div/1 /// `/` - "/=" pub struct DivEq/2 /// `/=` - "$" pub struct Dollar/1 /// `$` - "." pub struct Dot/1 /// `.` - ".." pub struct Dot2/2 /// `..` - "..." pub struct Dot3/3 /// `...` - "..=" pub struct DotDotEq/3 /// `..=` - "=" pub struct Eq/1 /// `=` - "==" pub struct EqEq/2 /// `==` - ">=" pub struct Ge/2 /// `>=` - ">" pub struct Gt/1 /// `>` - "<=" pub struct Le/2 /// `<=` - "<" pub struct Lt/1 /// `<` - "*=" pub struct MulEq/2 /// `*=` - "!=" pub struct Ne/2 /// `!=` - "|" pub struct Or/1 /// `|` - "|=" pub struct OrEq/2 /// `|=` - "||" pub struct OrOr/2 /// `||` - "#" pub struct Pound/1 /// `#` - "?" pub struct Question/1 /// `?` - "->" pub struct RArrow/2 /// `->` - "<-" pub struct LArrow/2 /// `<-` - "%" pub struct Rem/1 /// `%` - "%=" pub struct RemEq/2 /// `%=` - "=>" pub struct FatArrow/2 /// `=>` - ";" pub struct Semi/1 /// `;` - "<<" pub struct Shl/2 /// `<<` - "<<=" pub struct ShlEq/3 /// `<<=` - ">>" pub struct Shr/2 /// `>>` - ">>=" pub struct ShrEq/3 /// `>>=` - "*" pub struct Star/1 /// `*` - "-" pub struct Sub/1 /// `-` - "-=" pub struct SubEq/2 /// `-=` - "~" pub struct Tilde/1 /// `~` -} - -define_delimiters! { - "{" pub struct Brace /// `{...}` - "[" pub struct Bracket /// `[...]` - "(" pub struct Paren /// `(...)` - " " pub struct Group /// None-delimited group -} - -macro_rules! export_token_macro { - ($($await_rule:tt)*) => { - /// A type-macro that expands to the name of the Rust type representation of a - /// given token. - /// - /// See the [token module] documentation for details and examples. - /// - /// [token module]: crate::token - // Unfortunate duplication due to a rustdoc bug. - // https://github.com/rust-lang/rust/issues/45939 - #[macro_export] - macro_rules! Token { - (abstract) => { $crate::token::Abstract }; - (as) => { $crate::token::As }; - (async) => { $crate::token::Async }; - (auto) => { $crate::token::Auto }; - $($await_rule => { $crate::token::Await };)* - (become) => { $crate::token::Become }; - (box) => { $crate::token::Box }; - (break) => { $crate::token::Break }; - (const) => { $crate::token::Const }; - (continue) => { $crate::token::Continue }; - (crate) => { $crate::token::Crate }; - (default) => { $crate::token::Default }; - (do) => { $crate::token::Do }; - (dyn) => { $crate::token::Dyn }; - (else) => { $crate::token::Else }; - (enum) => { $crate::token::Enum }; - (extern) => { $crate::token::Extern }; - (final) => { $crate::token::Final }; - (fn) => { $crate::token::Fn }; - (for) => { $crate::token::For }; - (if) => { $crate::token::If }; - (impl) => { $crate::token::Impl }; - (in) => { $crate::token::In }; - (let) => { $crate::token::Let }; - (loop) => { $crate::token::Loop }; - (macro) => { $crate::token::Macro }; - (match) => { $crate::token::Match }; - (mod) => { $crate::token::Mod }; - (move) => { $crate::token::Move }; - (mut) => { $crate::token::Mut }; - (override) => { $crate::token::Override }; - (priv) => { $crate::token::Priv }; - (pub) => { $crate::token::Pub }; - (ref) => { $crate::token::Ref }; - (return) => { $crate::token::Return }; - (Self) => { $crate::token::SelfType }; - (self) => { $crate::token::SelfValue }; - (static) => { $crate::token::Static }; - (struct) => { $crate::token::Struct }; - (super) => { $crate::token::Super }; - (trait) => { $crate::token::Trait }; - (try) => { $crate::token::Try }; - (type) => { $crate::token::Type }; - (typeof) => { $crate::token::Typeof }; - (union) => { $crate::token::Union }; - (unsafe) => { $crate::token::Unsafe }; - (unsized) => { $crate::token::Unsized }; - (use) => { $crate::token::Use }; - (virtual) => { $crate::token::Virtual }; - (where) => { $crate::token::Where }; - (while) => { $crate::token::While }; - (yield) => { $crate::token::Yield }; - (+) => { $crate::token::Add }; - (+=) => { $crate::token::AddEq }; - (&) => { $crate::token::And }; - (&&) => { $crate::token::AndAnd }; - (&=) => { $crate::token::AndEq }; - (@) => { $crate::token::At }; - (!) => { $crate::token::Bang }; - (^) => { $crate::token::Caret }; - (^=) => { $crate::token::CaretEq }; - (:) => { $crate::token::Colon }; - (::) => { $crate::token::Colon2 }; - (,) => { $crate::token::Comma }; - (/) => { $crate::token::Div }; - (/=) => { $crate::token::DivEq }; - ($) => { $crate::token::Dollar }; - (.) => { $crate::token::Dot }; - (..) => { $crate::token::Dot2 }; - (...) => { $crate::token::Dot3 }; - (..=) => { $crate::token::DotDotEq }; - (=) => { $crate::token::Eq }; - (==) => { $crate::token::EqEq }; - (>=) => { $crate::token::Ge }; - (>) => { $crate::token::Gt }; - (<=) => { $crate::token::Le }; - (<) => { $crate::token::Lt }; - (*=) => { $crate::token::MulEq }; - (!=) => { $crate::token::Ne }; - (|) => { $crate::token::Or }; - (|=) => { $crate::token::OrEq }; - (||) => { $crate::token::OrOr }; - (#) => { $crate::token::Pound }; - (?) => { $crate::token::Question }; - (->) => { $crate::token::RArrow }; - (<-) => { $crate::token::LArrow }; - (%) => { $crate::token::Rem }; - (%=) => { $crate::token::RemEq }; - (=>) => { $crate::token::FatArrow }; - (;) => { $crate::token::Semi }; - (<<) => { $crate::token::Shl }; - (<<=) => { $crate::token::ShlEq }; - (>>) => { $crate::token::Shr }; - (>>=) => { $crate::token::ShrEq }; - (*) => { $crate::token::Star }; - (-) => { $crate::token::Sub }; - (-=) => { $crate::token::SubEq }; - (~) => { $crate::token::Tilde }; - (_) => { $crate::token::Underscore }; - } - }; -} - -// Old rustc does not permit `await` appearing anywhere in the source file. -// https://github.com/rust-lang/rust/issues/57919 -// We put the Token![await] rule in a place that is not lexed by old rustc. -#[cfg(not(syn_omit_await_from_token_macro))] -include!("await.rs"); // export_token_macro![(await)]; -#[cfg(syn_omit_await_from_token_macro)] -export_token_macro![]; - -// Not public API. -#[doc(hidden)] -#[cfg(feature = "parsing")] -pub mod parsing { - use proc_macro2::{Spacing, Span}; - - use crate::buffer::Cursor; - use crate::error::{Error, Result}; - use crate::parse::ParseStream; - use crate::span::FromSpans; - - pub fn keyword(input: ParseStream, token: &str) -> Result<Span> { - input.step(|cursor| { - if let Some((ident, rest)) = cursor.ident() { - if ident == token { - return Ok((ident.span(), rest)); - } - } - Err(cursor.error(format!("expected `{}`", token))) - }) - } - - pub fn peek_keyword(cursor: Cursor, token: &str) -> bool { - if let Some((ident, _rest)) = cursor.ident() { - ident == token - } else { - false - } - } - - pub fn punct<S: FromSpans>(input: ParseStream, token: &str) -> Result<S> { - let mut spans = [input.span(); 3]; - punct_helper(input, token, &mut spans)?; - Ok(S::from_spans(&spans)) - } - - fn punct_helper(input: ParseStream, token: &str, spans: &mut [Span; 3]) -> Result<()> { - input.step(|cursor| { - let mut cursor = *cursor; - assert!(token.len() <= spans.len()); - - for (i, ch) in token.chars().enumerate() { - match cursor.punct() { - Some((punct, rest)) => { - spans[i] = punct.span(); - if punct.as_char() != ch { - break; - } else if i == token.len() - 1 { - return Ok(((), rest)); - } else if punct.spacing() != Spacing::Joint { - break; - } - cursor = rest; - } - None => break, - } - } - - Err(Error::new(spans[0], format!("expected `{}`", token))) - }) - } - - pub fn peek_punct(mut cursor: Cursor, token: &str) -> bool { - for (i, ch) in token.chars().enumerate() { - match cursor.punct() { - Some((punct, rest)) => { - if punct.as_char() != ch { - break; - } else if i == token.len() - 1 { - return true; - } else if punct.spacing() != Spacing::Joint { - break; - } - cursor = rest; - } - None => break, - } - } - false - } -} - -// Not public API. -#[doc(hidden)] -#[cfg(feature = "printing")] -pub mod printing { - use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream}; - use quote::TokenStreamExt; - - pub fn punct(s: &str, spans: &[Span], tokens: &mut TokenStream) { - assert_eq!(s.len(), spans.len()); - - let mut chars = s.chars(); - let mut spans = spans.iter(); - let ch = chars.next_back().unwrap(); - let span = spans.next_back().unwrap(); - for (ch, span) in chars.zip(spans) { - let mut op = Punct::new(ch, Spacing::Joint); - op.set_span(*span); - tokens.append(op); - } - - let mut op = Punct::new(ch, Spacing::Alone); - op.set_span(*span); - tokens.append(op); - } - - pub fn keyword(s: &str, span: Span, tokens: &mut TokenStream) { - tokens.append(Ident::new(s, span)); - } - - pub fn delim<F>(s: &str, span: Span, tokens: &mut TokenStream, f: F) - where - F: FnOnce(&mut TokenStream), - { - let delim = match s { - "(" => Delimiter::Parenthesis, - "[" => Delimiter::Bracket, - "{" => Delimiter::Brace, - " " => Delimiter::None, - _ => panic!("unknown delimiter: {}", s), - }; - let mut inner = TokenStream::new(); - f(&mut inner); - let mut g = Group::new(delim, inner); - g.set_span(span); - tokens.append(g); - } -} |