rustell wip

Author: functora

rust/rustell/rustfmt.toml

@@ -1 +1,2 @@
 edition = "2024"
+max_width = 88

rust/rustell/src/main.rs

@@ -1,3 +1,42 @@
+use chumsky::prelude::*;
+use std::io::{self, Read};
+
+#[derive(Clone, Debug)]
+pub enum Stmt {
+    Expr,
+    Loop(Vec<Stmt>),
+}
+
+fn parser<'a>() -> impl Parser<'a, &'a str, Vec<Stmt>> {
+    let expr = just("expr"); // TODO
+
+    let block = recursive(|block| {
+        let indent = just(' ')
+            .repeated()
+            .configure(|cfg, parent_indent| cfg.exactly(*parent_indent));
+
+        let expr_stmt = expr.then_ignore(text::newline()).to(Stmt::Expr);
+        let control_flow = just("loop:")
+            .then(text::newline())
+            .ignore_then(block)
+            .map(Stmt::Loop);
+        let stmt = expr_stmt.or(control_flow);
+
+        text::whitespace()
+            .count()
+            .ignore_with_ctx(stmt.separated_by(indent).collect())
+    });
+
+    block.with_ctx(0)
+}
+
 fn main() {
-    println!("Hello, world!");
+    let mut src = String::new();
+    io::stdin()
+        .read_to_string(&mut src)
+        .expect("Failed to read stdin");
+    match parser().parse(src.trim()).into_result() {
+        Ok(ast) => println!("{:#?}", ast),
+        Err(errs) => errs.into_iter().for_each(|e| println!("{e:?}")),
+    };
 }