diff options
Diffstat (limited to 'compiler/rustc_ast/src/tokenstream.rs')
| -rw-r--r-- | compiler/rustc_ast/src/tokenstream.rs | 13 |
1 files changed, 1 insertions, 12 deletions
diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs index adc3056cc29..239735456ad 100644 --- a/compiler/rustc_ast/src/tokenstream.rs +++ b/compiler/rustc_ast/src/tokenstream.rs @@ -28,18 +28,7 @@ use smallvec::{smallvec, SmallVec}; use std::borrow::Cow; use std::{cmp, fmt, iter}; -/// When the main Rust parser encounters a syntax-extension invocation, it -/// parses the arguments to the invocation as a token tree. This is a very -/// loose structure, such that all sorts of different AST fragments can -/// be passed to syntax extensions using a uniform type. -/// -/// If the syntax extension is an MBE macro, it will attempt to match its -/// LHS token tree against the provided token tree, and if it finds a -/// match, will transcribe the RHS token tree, splicing in any captured -/// `macro_parser::matched_nonterminals` into the `SubstNt`s it finds. -/// -/// The RHS of an MBE macro is the only place `SubstNt`s are substituted. -/// Nothing special happens to misnamed or misplaced `SubstNt`s. +/// Part of a `TokenStream`. #[derive(Debug, Clone, PartialEq, Encodable, Decodable, HashStable_Generic)] pub enum TokenTree { /// A single token. Should never be `OpenDelim` or `CloseDelim`, because |