Prepare parser for function definitions

src/parser/func_defs.rs

@@ -0,0 +1,11 @@
+use chumsky::prelude::*;
+
+use crate::ast::{Expr, FuncDef};
+
+use super::basic::Error;
+
+pub fn func_def(
+    expr: impl Parser<char, Expr, Error = Error>,
+) -> BoxedParser<'static, char, FuncDef, Error> {
+    todo().boxed()
+}