pub use BinOpToken::*; pub use LitKind::*; pub use Nonterminal::*; pub use TokenKind::*; use crate::ast; use crate::ptr::P; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::sync::Lrc; use rustc_macros::HashStable_Generic; use rustc_span::symbol::{kw, sym}; use rustc_span::symbol::{Ident, Symbol}; use rustc_span::{self, edition::Edition, Span, DUMMY_SP}; use std::borrow::Cow; use std::{fmt, mem}; #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)] pub enum CommentKind { Line, Block, } #[derive(Clone, PartialEq, Encodable, Decodable, Hash, Debug, Copy)] #[derive(HashStable_Generic)] pub enum BinOpToken { Plus, Minus, Star, Slash, Percent, Caret, And, Or, Shl, Shr, } /// Describes how a sequence of token trees is delimited. /// Cannot use `proc_macro::Delimiter` directly because this /// structure should implement some additional traits. /// The `None` variant is also renamed to `Invisible` to be /// less confusing and better convey the semantics. #[derive(Copy, Clone, Debug, PartialEq, Eq)] #[derive(Encodable, Decodable, Hash, HashStable_Generic)] pub enum Delimiter { /// `( ... )` Parenthesis, /// `{ ... }` Brace, /// `[ ... ]` Bracket, /// `Ø ... Ø` /// An invisible delimiter, that may, for example, appear around tokens coming from a /// "macro variable" `$var`. It is important to preserve operator priorities in cases like /// `$var * 3` where `$var` is `1 + 2`. /// Invisible delimiters might not survive roundtrip of a token stream through a string. Invisible, } #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)] pub enum LitKind { Bool, // AST only, must never appear in a `Token` Byte, Char, Integer, Float, Str, StrRaw(u8), // raw string delimited by `n` hash symbols ByteStr, ByteStrRaw(u8), // raw byte string delimited by `n` hash symbols Err, } /// A literal token. #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)] pub struct Lit { pub kind: LitKind, pub symbol: Symbol, pub suffix: Option, } impl fmt::Display for Lit { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let Lit { kind, symbol, suffix } = *self; match kind { Byte => write!(f, "b'{}'", symbol)?, Char => write!(f, "'{}'", symbol)?, Str => write!(f, "\"{}\"", symbol)?, StrRaw(n) => write!( f, "r{delim}\"{string}\"{delim}", delim = "#".repeat(n as usize), string = symbol )?, ByteStr => write!(f, "b\"{}\"", symbol)?, ByteStrRaw(n) => write!( f, "br{delim}\"{string}\"{delim}", delim = "#".repeat(n as usize), string = symbol )?, Integer | Float | Bool | Err => write!(f, "{}", symbol)?, } if let Some(suffix) = suffix { write!(f, "{}", suffix)?; } Ok(()) } } impl LitKind { /// An English article for the literal token kind. pub fn article(self) -> &'static str { match self { Integer | Err => "an", _ => "a", } } pub fn descr(self) -> &'static str { match self { Bool => panic!("literal token contains `Lit::Bool`"), Byte => "byte", Char => "char", Integer => "integer", Float => "float", Str | StrRaw(..) => "string", ByteStr | ByteStrRaw(..) => "byte string", Err => "error", } } pub(crate) fn may_have_suffix(self) -> bool { matches!(self, Integer | Float | Err) } } impl Lit { pub fn new(kind: LitKind, symbol: Symbol, suffix: Option) -> Lit { Lit { kind, symbol, suffix } } } pub fn ident_can_begin_expr(name: Symbol, span: Span, is_raw: bool) -> bool { let ident_token = Token::new(Ident(name, is_raw), span); !ident_token.is_reserved_ident() || ident_token.is_path_segment_keyword() || [ kw::Async, kw::Do, kw::Box, kw::Break, kw::Const, kw::Continue, kw::False, kw::For, kw::If, kw::Let, kw::Loop, kw::Match, kw::Move, kw::Return, kw::True, kw::Try, kw::Unsafe, kw::While, kw::Yield, kw::Static, ] .contains(&name) } fn ident_can_begin_type(name: Symbol, span: Span, is_raw: bool) -> bool { let ident_token = Token::new(Ident(name, is_raw), span); !ident_token.is_reserved_ident() || ident_token.is_path_segment_keyword() || [kw::Underscore, kw::For, kw::Impl, kw::Fn, kw::Unsafe, kw::Extern, kw::Typeof, kw::Dyn] .contains(&name) } #[derive(Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)] pub enum TokenKind { /* Expression-operator symbols. */ Eq, Lt, Le, EqEq, Ne, Ge, Gt, AndAnd, OrOr, Not, Tilde, BinOp(BinOpToken), BinOpEq(BinOpToken), /* Structural symbols */ At, Dot, DotDot, DotDotDot, DotDotEq, Comma, Semi, Colon, ModSep, RArrow, LArrow, FatArrow, Pound, Dollar, Question, /// Used by proc macros for representing lifetimes, not generated by lexer right now. SingleQuote, /// An opening delimiter (e.g., `{`). OpenDelim(Delimiter), /// A closing delimiter (e.g., `}`). CloseDelim(Delimiter), /* Literals */ Literal(Lit), /// Identifier token. /// Do not forget about `NtIdent` when you want to match on identifiers. /// It's recommended to use `Token::(ident,uninterpolate,uninterpolated_span)` to /// treat regular and interpolated identifiers in the same way. Ident(Symbol, /* is_raw */ bool), /// Lifetime identifier token. /// Do not forget about `NtLifetime` when you want to match on lifetime identifiers. /// It's recommended to use `Token::(lifetime,uninterpolate,uninterpolated_span)` to /// treat regular and interpolated lifetime identifiers in the same way. Lifetime(Symbol), /// An embedded AST node, as produced by a macro. This only exists for /// historical reasons. We'd like to get rid of it, for multiple reasons. /// - It's conceptually very strange. Saying a token can contain an AST /// node is like saying, in natural language, that a word can contain a /// sentence. /// - It requires special handling in a bunch of places in the parser. /// - It prevents `Token` from implementing `Copy`. /// It adds complexity and likely slows things down. Please don't add new /// occurrences of this token kind! Interpolated(Lrc), /// A doc comment token. /// `Symbol` is the doc comment's data excluding its "quotes" (`///`, `/**`, etc) /// similarly to symbols in string literal tokens. DocComment(CommentKind, ast::AttrStyle, Symbol), Eof, } // `TokenKind` is used a lot. Make sure it doesn't unintentionally get bigger. #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] rustc_data_structures::static_assert_size!(TokenKind, 16); #[derive(Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)] pub struct Token { pub kind: TokenKind, pub span: Span, } impl TokenKind { pub fn lit(kind: LitKind, symbol: Symbol, suffix: Option) -> TokenKind { Literal(Lit::new(kind, symbol, suffix)) } // An approximation to proc-macro-style single-character operators used by rustc parser. // If the operator token can be broken into two tokens, the first of which is single-character, // then this function performs that operation, otherwise it returns `None`. pub fn break_two_token_op(&self) -> Option<(TokenKind, TokenKind)> { Some(match *self { Le => (Lt, Eq), EqEq => (Eq, Eq), Ne => (Not, Eq), Ge => (Gt, Eq), AndAnd => (BinOp(And), BinOp(And)), OrOr => (BinOp(Or), BinOp(Or)), BinOp(Shl) => (Lt, Lt), BinOp(Shr) => (Gt, Gt), BinOpEq(Plus) => (BinOp(Plus), Eq), BinOpEq(Minus) => (BinOp(Minus), Eq), BinOpEq(Star) => (BinOp(Star), Eq), BinOpEq(Slash) => (BinOp(Slash), Eq), BinOpEq(Percent) => (BinOp(Percent), Eq), BinOpEq(Caret) => (BinOp(Caret), Eq), BinOpEq(And) => (BinOp(And), Eq), BinOpEq(Or) => (BinOp(Or), Eq), BinOpEq(Shl) => (Lt, Le), BinOpEq(Shr) => (Gt, Ge), DotDot => (Dot, Dot), DotDotDot => (Dot, DotDot), ModSep => (Colon, Colon), RArrow => (BinOp(Minus), Gt), LArrow => (Lt, BinOp(Minus)), FatArrow => (Eq, Gt), _ => return None, }) } /// Returns tokens that are likely to be typed accidentally instead of the current token. /// Enables better error recovery when the wrong token is found. pub fn similar_tokens(&self) -> Option> { match *self { Comma => Some(vec![Dot, Lt, Semi]), Semi => Some(vec![Colon, Comma]), FatArrow => Some(vec![Eq, RArrow]), _ => None, } } pub fn should_end_const_arg(&self) -> bool { matches!(self, Gt | Ge | BinOp(Shr) | BinOpEq(Shr)) } } impl Token { pub fn new(kind: TokenKind, span: Span) -> Self { Token { kind, span } } /// Some token that will be thrown away later. pub fn dummy() -> Self { Token::new(TokenKind::Question, DUMMY_SP) } /// Recovers a `Token` from an `Ident`. This creates a raw identifier if necessary. pub fn from_ast_ident(ident: Ident) -> Self { Token::new(Ident(ident.name, ident.is_raw_guess()), ident.span) } /// Return this token by value and leave a dummy token in its place. pub fn take(&mut self) -> Self { mem::replace(self, Token::dummy()) } /// For interpolated tokens, returns a span of the fragment to which the interpolated /// token refers. For all other tokens this is just a regular span. /// It is particularly important to use this for identifiers and lifetimes /// for which spans affect name resolution and edition checks. /// Note that keywords are also identifiers, so they should use this /// if they keep spans or perform edition checks. pub fn uninterpolated_span(&self) -> Span { match &self.kind { Interpolated(nt) => nt.span(), _ => self.span, } } pub fn is_op(&self) -> bool { !matches!( self.kind, OpenDelim(..) | CloseDelim(..) | Literal(..) | DocComment(..) | Ident(..) | Lifetime(..) | Interpolated(..) | Eof ) } pub fn is_like_plus(&self) -> bool { matches!(self.kind, BinOp(Plus) | BinOpEq(Plus)) } /// Returns `true` if the token can appear at the start of an expression. pub fn can_begin_expr(&self) -> bool { match self.uninterpolate().kind { Ident(name, is_raw) => ident_can_begin_expr(name, self.span, is_raw), // value name or keyword OpenDelim(..) | // tuple, array or block Literal(..) | // literal Not | // operator not BinOp(Minus) | // unary minus BinOp(Star) | // dereference BinOp(Or) | OrOr | // closure BinOp(And) | // reference AndAnd | // double reference // DotDotDot is no longer supported, but we need some way to display the error DotDot | DotDotDot | DotDotEq | // range notation Lt | BinOp(Shl) | // associated path ModSep | // global path Lifetime(..) | // labeled loop Pound => true, // expression attributes Interpolated(ref nt) => matches!(**nt, NtLiteral(..) | NtExpr(..) | NtBlock(..) | NtPath(..)), _ => false, } } /// Returns `true` if the token can appear at the start of a type. pub fn can_begin_type(&self) -> bool { match self.uninterpolate().kind { Ident(name, is_raw) => ident_can_begin_type(name, self.span, is_raw), // type name or keyword OpenDelim(Delimiter::Parenthesis) | // tuple OpenDelim(Delimiter::Bracket) | // array Not | // never BinOp(Star) | // raw pointer BinOp(And) | // reference AndAnd | // double reference Question | // maybe bound in trait object Lifetime(..) | // lifetime bound in trait object Lt | BinOp(Shl) | // associated path ModSep => true, // global path Interpolated(ref nt) => matches!(**nt, NtTy(..) | NtPath(..)), _ => false, } } /// Returns `true` if the token can appear at the start of a const param. pub fn can_begin_const_arg(&self) -> bool { match self.kind { OpenDelim(Delimiter::Brace) => true, Interpolated(ref nt) => matches!(**nt, NtExpr(..) | NtBlock(..) | NtLiteral(..)), _ => self.can_begin_literal_maybe_minus(), } } /// Returns `true` if the token can appear at the start of a generic bound. pub fn can_begin_bound(&self) -> bool { self.is_path_start() || self.is_lifetime() || self.is_keyword(kw::For) || self == &Question || self == &OpenDelim(Delimiter::Parenthesis) } /// Returns `true` if the token is any literal. pub fn is_lit(&self) -> bool { matches!(self.kind, Literal(..)) } /// Returns `true` if the token is any literal, a minus (which can prefix a literal, /// for example a '-42', or one of the boolean idents). /// /// In other words, would this token be a valid start of `parse_literal_maybe_minus`? /// /// Keep this in sync with and `Lit::from_token`, excluding unary negation. pub fn can_begin_literal_maybe_minus(&self) -> bool { match self.uninterpolate().kind { Literal(..) | BinOp(Minus) => true, Ident(name, false) if name.is_bool_lit() => true, Interpolated(ref nt) => match &**nt { NtLiteral(_) => true, NtExpr(e) => match &e.kind { ast::ExprKind::Lit(_) => true, ast::ExprKind::Unary(ast::UnOp::Neg, e) => { matches!(&e.kind, ast::ExprKind::Lit(_)) } _ => false, }, _ => false, }, _ => false, } } // A convenience function for matching on identifiers during parsing. // Turns interpolated identifier (`$i: ident`) or lifetime (`$l: lifetime`) token // into the regular identifier or lifetime token it refers to, // otherwise returns the original token. pub fn uninterpolate(&self) -> Cow<'_, Token> { match &self.kind { Interpolated(nt) => match **nt { NtIdent(ident, is_raw) => { Cow::Owned(Token::new(Ident(ident.name, is_raw), ident.span)) } NtLifetime(ident) => Cow::Owned(Token::new(Lifetime(ident.name), ident.span)), _ => Cow::Borrowed(self), }, _ => Cow::Borrowed(self), } } /// Returns an identifier if this token is an identifier. #[inline] pub fn ident(&self) -> Option<(Ident, /* is_raw */ bool)> { // We avoid using `Token::uninterpolate` here because it's slow. match &self.kind { &Ident(name, is_raw) => Some((Ident::new(name, self.span), is_raw)), Interpolated(nt) => match **nt { NtIdent(ident, is_raw) => Some((ident, is_raw)), _ => None, }, _ => None, } } /// Returns a lifetime identifier if this token is a lifetime. #[inline] pub fn lifetime(&self) -> Option { // We avoid using `Token::uninterpolate` here because it's slow. match &self.kind { &Lifetime(name) => Some(Ident::new(name, self.span)), Interpolated(nt) => match **nt { NtLifetime(ident) => Some(ident), _ => None, }, _ => None, } } /// Returns `true` if the token is an identifier. pub fn is_ident(&self) -> bool { self.ident().is_some() } /// Returns `true` if the token is a lifetime. pub fn is_lifetime(&self) -> bool { self.lifetime().is_some() } /// Returns `true` if the token is an identifier whose name is the given /// string slice. pub fn is_ident_named(&self, name: Symbol) -> bool { self.ident().map_or(false, |(ident, _)| ident.name == name) } /// Returns `true` if the token is an interpolated path. fn is_path(&self) -> bool { if let Interpolated(ref nt) = self.kind && let NtPath(..) = **nt { return true; } false } /// Would `maybe_whole_expr` in `parser.rs` return `Ok(..)`? /// That is, is this a pre-parsed expression dropped into the token stream /// (which happens while parsing the result of macro expansion)? pub fn is_whole_expr(&self) -> bool { if let Interpolated(ref nt) = self.kind && let NtExpr(_) | NtLiteral(_) | NtPath(_) | NtBlock(_) = **nt { return true; } false } // Is the token an interpolated block (`$b:block`)? pub fn is_whole_block(&self) -> bool { if let Interpolated(ref nt) = self.kind && let NtBlock(..) = **nt { return true; } false } /// Returns `true` if the token is either the `mut` or `const` keyword. pub fn is_mutability(&self) -> bool { self.is_keyword(kw::Mut) || self.is_keyword(kw::Const) } pub fn is_qpath_start(&self) -> bool { self == &Lt || self == &BinOp(Shl) } pub fn is_path_start(&self) -> bool { self == &ModSep || self.is_qpath_start() || self.is_path() || self.is_path_segment_keyword() || self.is_ident() && !self.is_reserved_ident() } /// Returns `true` if the token is a given keyword, `kw`. pub fn is_keyword(&self, kw: Symbol) -> bool { self.is_non_raw_ident_where(|id| id.name == kw) } pub fn is_path_segment_keyword(&self) -> bool { self.is_non_raw_ident_where(Ident::is_path_segment_keyword) } // Returns true for reserved identifiers used internally for elided lifetimes, // unnamed method parameters, crate root module, error recovery etc. pub fn is_special_ident(&self) -> bool { self.is_non_raw_ident_where(Ident::is_special) } /// Returns `true` if the token is a keyword used in the language. pub fn is_used_keyword(&self) -> bool { self.is_non_raw_ident_where(Ident::is_used_keyword) } /// Returns `true` if the token is a keyword reserved for possible future use. pub fn is_unused_keyword(&self) -> bool { self.is_non_raw_ident_where(Ident::is_unused_keyword) } /// Returns `true` if the token is either a special identifier or a keyword. pub fn is_reserved_ident(&self) -> bool { self.is_non_raw_ident_where(Ident::is_reserved) } /// Returns `true` if the token is the identifier `true` or `false`. pub fn is_bool_lit(&self) -> bool { self.is_non_raw_ident_where(|id| id.name.is_bool_lit()) } pub fn is_numeric_lit(&self) -> bool { matches!( self.kind, Literal(Lit { kind: LitKind::Integer, .. }) | Literal(Lit { kind: LitKind::Float, .. }) ) } /// Returns `true` if the token is a non-raw identifier for which `pred` holds. pub fn is_non_raw_ident_where(&self, pred: impl FnOnce(Ident) -> bool) -> bool { match self.ident() { Some((id, false)) => pred(id), _ => false, } } pub fn glue(&self, joint: &Token) -> Option { let kind = match self.kind { Eq => match joint.kind { Eq => EqEq, Gt => FatArrow, _ => return None, }, Lt => match joint.kind { Eq => Le, Lt => BinOp(Shl), Le => BinOpEq(Shl), BinOp(Minus) => LArrow, _ => return None, }, Gt => match joint.kind { Eq => Ge, Gt => BinOp(Shr), Ge => BinOpEq(Shr), _ => return None, }, Not => match joint.kind { Eq => Ne, _ => return None, }, BinOp(op) => match joint.kind { Eq => BinOpEq(op), BinOp(And) if op == And => AndAnd, BinOp(Or) if op == Or => OrOr, Gt if op == Minus => RArrow, _ => return None, }, Dot => match joint.kind { Dot => DotDot, DotDot => DotDotDot, _ => return None, }, DotDot => match joint.kind { Dot => DotDotDot, Eq => DotDotEq, _ => return None, }, Colon => match joint.kind { Colon => ModSep, _ => return None, }, SingleQuote => match joint.kind { Ident(name, false) => Lifetime(Symbol::intern(&format!("'{}", name))), _ => return None, }, Le | EqEq | Ne | Ge | AndAnd | OrOr | Tilde | BinOpEq(..) | At | DotDotDot | DotDotEq | Comma | Semi | ModSep | RArrow | LArrow | FatArrow | Pound | Dollar | Question | OpenDelim(..) | CloseDelim(..) | Literal(..) | Ident(..) | Lifetime(..) | Interpolated(..) | DocComment(..) | Eof => return None, }; Some(Token::new(kind, self.span.to(joint.span))) } } impl PartialEq for Token { fn eq(&self, rhs: &TokenKind) -> bool { self.kind == *rhs } } #[derive(Clone, Encodable, Decodable)] /// For interpolation during macro expansion. pub enum Nonterminal { NtItem(P), NtBlock(P), NtStmt(P), NtPat(P), NtExpr(P), NtTy(P), NtIdent(Ident, /* is_raw */ bool), NtLifetime(Ident), NtLiteral(P), /// Stuff inside brackets for attributes NtMeta(P), NtPath(P), NtVis(P), } // `Nonterminal` is used a lot. Make sure it doesn't unintentionally get bigger. #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] rustc_data_structures::static_assert_size!(Nonterminal, 16); #[derive(Debug, Copy, Clone, PartialEq, Encodable, Decodable)] pub enum NonterminalKind { Item, Block, Stmt, PatParam { /// Keep track of whether the user used `:pat_param` or `:pat` and we inferred it from the /// edition of the span. This is used for diagnostics. inferred: bool, }, PatWithOr, Expr, Ty, Ident, Lifetime, Literal, Meta, Path, Vis, TT, } impl NonterminalKind { /// The `edition` closure is used to get the edition for the given symbol. Doing /// `span.edition()` is expensive, so we do it lazily. pub fn from_symbol( symbol: Symbol, edition: impl FnOnce() -> Edition, ) -> Option { Some(match symbol { sym::item => NonterminalKind::Item, sym::block => NonterminalKind::Block, sym::stmt => NonterminalKind::Stmt, sym::pat => match edition() { Edition::Edition2015 | Edition::Edition2018 => { NonterminalKind::PatParam { inferred: true } } Edition::Edition2021 | Edition::Edition2024 => NonterminalKind::PatWithOr, }, sym::pat_param => NonterminalKind::PatParam { inferred: false }, sym::expr => NonterminalKind::Expr, sym::ty => NonterminalKind::Ty, sym::ident => NonterminalKind::Ident, sym::lifetime => NonterminalKind::Lifetime, sym::literal => NonterminalKind::Literal, sym::meta => NonterminalKind::Meta, sym::path => NonterminalKind::Path, sym::vis => NonterminalKind::Vis, sym::tt => NonterminalKind::TT, _ => return None, }) } fn symbol(self) -> Symbol { match self { NonterminalKind::Item => sym::item, NonterminalKind::Block => sym::block, NonterminalKind::Stmt => sym::stmt, NonterminalKind::PatParam { inferred: false } => sym::pat_param, NonterminalKind::PatParam { inferred: true } | NonterminalKind::PatWithOr => sym::pat, NonterminalKind::Expr => sym::expr, NonterminalKind::Ty => sym::ty, NonterminalKind::Ident => sym::ident, NonterminalKind::Lifetime => sym::lifetime, NonterminalKind::Literal => sym::literal, NonterminalKind::Meta => sym::meta, NonterminalKind::Path => sym::path, NonterminalKind::Vis => sym::vis, NonterminalKind::TT => sym::tt, } } } impl fmt::Display for NonterminalKind { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "{}", self.symbol()) } } impl Nonterminal { pub fn span(&self) -> Span { match self { NtItem(item) => item.span, NtBlock(block) => block.span, NtStmt(stmt) => stmt.span, NtPat(pat) => pat.span, NtExpr(expr) | NtLiteral(expr) => expr.span, NtTy(ty) => ty.span, NtIdent(ident, _) | NtLifetime(ident) => ident.span, NtMeta(attr_item) => attr_item.span(), NtPath(path) => path.span, NtVis(vis) => vis.span, } } } impl PartialEq for Nonterminal { fn eq(&self, rhs: &Self) -> bool { match (self, rhs) { (NtIdent(ident_lhs, is_raw_lhs), NtIdent(ident_rhs, is_raw_rhs)) => { ident_lhs == ident_rhs && is_raw_lhs == is_raw_rhs } (NtLifetime(ident_lhs), NtLifetime(ident_rhs)) => ident_lhs == ident_rhs, // FIXME: Assume that all "complex" nonterminal are not equal, we can't compare them // correctly based on data from AST. This will prevent them from matching each other // in macros. The comparison will become possible only when each nonterminal has an // attached token stream from which it was parsed. _ => false, } } } impl fmt::Debug for Nonterminal { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match *self { NtItem(..) => f.pad("NtItem(..)"), NtBlock(..) => f.pad("NtBlock(..)"), NtStmt(..) => f.pad("NtStmt(..)"), NtPat(..) => f.pad("NtPat(..)"), NtExpr(..) => f.pad("NtExpr(..)"), NtTy(..) => f.pad("NtTy(..)"), NtIdent(..) => f.pad("NtIdent(..)"), NtLiteral(..) => f.pad("NtLiteral(..)"), NtMeta(..) => f.pad("NtMeta(..)"), NtPath(..) => f.pad("NtPath(..)"), NtVis(..) => f.pad("NtVis(..)"), NtLifetime(..) => f.pad("NtLifetime(..)"), } } } impl HashStable for Nonterminal where CTX: crate::HashStableContext, { fn hash_stable(&self, _hcx: &mut CTX, _hasher: &mut StableHasher) { panic!("interpolated tokens should not be present in the HIR") } }