work

src/main.rs

@@ -7,6 +7,13 @@ mod ir;
 mod parser;
 
 fn main() {
-    parser::main();
+    let arg = std::env::args_os().nth(1);
+    if let Some(path) = arg {
+        let file = std::fs::read_to_string(path).expect("failed to read file");
+        println!("{file}");
+        parser::parse_file(&file);
+    } else {
+        parser::run_stdin();
+    }
     // compiler::main();
 }