Re:Show HN: Pest – Fast parser generator written in Rust
by dikaiosune on Sunday August 27, 2017 @03:42PM
(#15112328)
There's actually a parser for rust called syn, and it's very useful for procedural macros, as the current API exposes a stream of tokens, not a full AST.
[ Parent
| on HN ]
Re:Show HN: Pest – Fast parser generator written in Rust
by steveklabnik on Sunday August 27, 2017 @04:03PM
(#15112409)
To elaborate a bit on that, exposing an AST directly means that you're tied to that version of the AST; this was considered really hard for compatibility over versions. Token streams are much easier to define an interface for, and more flexible: you're not just stuck with whatever AST representation we'd have given you.
For example: https://doc.rust-lang.org/book/first-edition/procedural-macr...