WIP generating Python module is optional

Cargo.toml

@@ -26,6 +26,7 @@ markdown = ["termimad"]
 repl = ["rustyline", "rustyline-derive", "ansi_term"]
 repl-wasm = ["wasm-bindgen", "js-sys", "serde_repr"]
 doc = [ "comrak" ]
+python-module = [ "pyo3" ]
 
 [build-dependencies]
 lalrpop = "0.19.6"
@@ -66,7 +67,7 @@ comrak = { version = "0.12.1", optional = true, features = [] }
 once_cell = "1.14.0"
 typed-arena = "2.0.1"
 
-pyo3 = { version = "0.17.3", features = ["extension-module"] }
+pyo3 = { version = "0.17.3", optional = true, features = ["extension-module"] }
 
 [dev-dependencies]
 pretty_assertions = "1.2.1"

pyproject.toml

@@ -0,0 +1,7 @@
+[build-system]
+requires = ["maturin>=0.14,<0.15"]
+build-backend = "maturin"
+
+[tool.maturin]
+cargo-extra-args = "--features python-module"
+

src/lib.rs

@@ -10,6 +10,7 @@ pub mod parser;
 pub mod position;
 pub mod pretty;
 pub mod program;
+#[cfg(feature = "python-module")]
 pub mod python;
 pub mod repl;
 pub mod serialize;