diff --git a/flake.nix b/flake.nix
index 8f30908..e5c7897 100644
--- a/flake.nix
+++ b/flake.nix
@@ -54,18 +54,8 @@
       combine [
         complete.toolchain
       ];
-    # rs-platform = pkgs.makeRustPlatform {
-    #   cargo = rs-toolchain;
-    #   rustc = rs-toolchain;
-    # };
     crane-lib = (crane.mkLib nixpkgs.legacyPackages.${system}).overrideToolchain rs-toolchain;
     rs-programs = final: prev: {
-      # s10e-jrnl = rs-platform.buildRustPackage {
-      #   pname = "jrnl";
-      #   version = "0.0.1";
-      #   src = ./programs/jrnl;
-      #   cargoLock.lockFile = ./programs/jrnl/Cargo.lock;
-      # };
       s10e-jrnl = crane-lib.buildPackage {
         pname = "s10e-bs";
         version = "0.0.1";
diff --git a/programs/flip-bool/src/main.rs b/programs/flip-bool/src/main.rs
index 0b99ab8..8062888 100644
--- a/programs/flip-bool/src/main.rs
+++ b/programs/flip-bool/src/main.rs
@@ -1,7 +1,4 @@
-#![feature(iter_array_chunks)]
-#![feature(round_char_boundary)]
-#![feature(iter_collect_into)]
-#![feature(pattern)]
+#![feature(pattern, iter_array_chunks, round_char_boundary, iter_collect_into)]
 
 use std::{
     io::{Read, Write},
@@ -17,17 +14,16 @@ const BOOLS: &[[&str; 2]] = &[
     ["no", "yes"],
 ];
 
-fn main() {
+fn main() -> std::io::Result<()> {
     let mut input = String::new();
     let mut stdin = std::io::stdin();
     let mut stdout = std::io::stdout();
 
-    stdin.read_to_string(&mut input).unwrap();
+    stdin.read_to_string(&mut input)?;
 
     let bool_locs = find_bools(&input);
-    stdout
-        .write_all(replace_bools(&mut input, bool_locs).as_bytes())
-        .unwrap();
+
+    stdout.write_all(replace_bools(&mut input, bool_locs).as_bytes())
 }
 
 type BoolLocs = [[Vec<usize>; 2]; BOOL_COUNT];
@@ -96,14 +92,12 @@ fn find_bools(input: &str) -> [[Vec<usize>; 2]; BOOL_COUNT] {
                         && char_guard(
                             input[it.1.floor_char_boundary(it.0 - 1)..it.0]
                                 .chars()
-                                .last()
-                                .unwrap(),
+                                .last()?,
                         )
                         && char_guard(
                             input[(last_idx)..(input.ceil_char_boundary(last_idx + 1))]
                                 .chars()
-                                .last()
-                                .unwrap(),
+                                .last()?,
                         ))
                     .then_some(it.0)
                 })