.

README.md

@@ -10,8 +10,7 @@ because the operating system itself is the runtime.
 git clone https://github.com/knarkzel/knarkos
 cd knarkos 
 nix develop # or nix-shell
-cd os/
-cargo run
+just build
 ```
 
 ## Goals

lisp/Cargo.toml

@@ -3,6 +3,5 @@ name = "lisp"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
+nom = "7.1.3"

lisp/src/main.rs

@@ -1,3 +1,35 @@
+use nom::{
+    branch::alt,
+    bytes::complete::{tag, take_while_m_n},
+    combinator::{map, map_res},
+    sequence::tuple,
+    IResult,
+};
+
+enum Operator {
+    Plus,
+    Minus,
+    Times,
+    Divide,
+}
+
+// Atoms
+enum Atom {
+    Number(i32),
+    Operator(Operator),
+}
+
+fn parse_atom(input: &str) -> IResult<&str, Atom> {
+    map(
+        alt((
+            map(tag("+"), |_| Operator::Plus),
+            map(tag("-"), |_| Operator::Minus),
+            map(tag("*"), |_| Operator::Times),
+            map(tag("/"), |_| Operator::Divide),
+        )),
+        |operator| Atom::Operator(operator),
+    )(input)
+}
+
 fn main() {
-    println!("Hello, world!");
 }