feat: bring flay's transformer to rustpython-unparser

Author: jvllmr

Cargo.toml

@@ -9,6 +9,9 @@ description = "A complete unparser for RustPython ASTs"
 license-file = "LICENSE"
 rust-version = "1.72.1"
 
+[features]
+transformer = []
+
 [dependencies]
 rustpython-ast = { version = ">=0.4.0" }
 rustpython-literal = ">=0.4.0"

README.md

@@ -34,3 +34,7 @@ fn main() {
     // ...
 }
 ```
+
+# Transformer
+
+This crate also contains a transformer trait for easy transformation of ASTs with the possibility of removing nodes. Enable the `transformer` feature to use it. It is similar to rustpython-ast's visitor, with the difference that a visit functions always return `Option<...>` and statements/expressions are passed as mutable.

src/lib.rs

@@ -1,7 +1,8 @@
 pub mod unparser;
 mod utils;
 pub use crate::unparser::Unparser;
-
+#[cfg(feature = "transformer")]
+pub mod transformer;
 #[cfg(test)]
 mod tests {
     use super::*;