feat: implement basic read-eval-print loop

src/main.rs

@@ -1,3 +1,30 @@
-fn main() {
-    println!("Hello, world!");
-}
+use rustyline::error::ReadlineError;
+use rustyline::{Editor, Result};
+
+fn main() -> Result<()> {
+    let mut rl = Editor::<()>::new()?;
+
+    loop {
+        let readline = rl.readline("» ");
+
+        match readline {
+            Ok(line) => {
+                println!("Line: {}", line);
+            },
+            Err(ReadlineError::Interrupted) => {
+                println!("CTRL-C");
+                break
+            },
+            Err(ReadlineError::Eof) => {
+                println!("CTRL-D");
+                break
+            },
+            Err(err) => {
+                println!("Error: {:?}", err);
+                break
+            }
+        }
+    }
+
+    Ok(())
+}