src/lib.rs

@@ -0,0 +1,12 @@
+use std::error::Error;
+
+mod card;
+mod hand;
+mod deck;
+mod gamestate;
+
+pub fn run() -> Result<(), Box<dyn Error>> {
+    println!("Hello, world!");
+
+    Ok(())
+}

src/main.rs

@@ -1,3 +1,8 @@
-fn main() {
-    println!("Hello, world!");
+use blackjack::run;
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    run()?;
+
+    Ok(())
 }