# Any-sexpr
This is an S-Expression parser and formatter with the following goals:
* Offering direct access to the tokenizer, `anysexpr::parse`, but also
`anysexpr::read` to build an in-memory tree easily.
* Good error reporting (precise location information and
messages).
* (Future) Make the data constructors for `anysexpr::read`
parametrizable (generic), e.g. like in the `sexpr_parser` crate.
* Streaming: allow to read from and print to file handles lazily, for
use e.g. in communications. This currently works by using
`anysexpr::parse` directly for input, or creating tokens to print
via a custom loop for output. Future: more possibilities, e.g. turn
a tree into a token stream, or parameterize with a tree that's
generated on demand while printing.
* (Future) Support various s-expression variants (R*RS, Guile, Clojure,
Common Lisp, ..) via runtime (and compile-time?) settings.
* (Perhaps) be usable on microcontrollers (small code, no-std?).
The author is quite new to Rust. There will be API guideline entries
not currently being followed, help in that area is as welcome as in
other areas.
## Usage
See [examples/main.rs](examples/main.rs).
## Todo
* string escape features on printing
* inexact and complex numbers
* performance tuning?, perhaps do not use genawaiter?
* better error behaviour: parser should return errors but try to make
it possible to continue?
* more tests (large test corpora, fuzzing round trips)
* handle Guile, Clojure and other syntax versions
* parametrization (generics) for tree generation / mapping (also/vs. Serde?)
* lazy features as mentioned above
* some level of support for pretty-printing
Orthogonally:
* examine the `lexpr` crate in more detail (missed when researching
existing crates before starting this project)
## Contact
Christian Jaeger <ch@christianjaeger.ch>