feat: wire up the parser in the main function

src/main.rs

@@ -1,5 +1,30 @@
+use std::{env::args, fs::read_to_string, process::exit};
+
+use crate::frontend::parser::Parser;
+
 pub mod frontend;
 
 fn main() {
-    println!("Hello, world!");
+    let Some(path) = args().nth(1) else {
+        eprintln!("usage: compiler <file>");
+        exit(1);
+    };
+
+    let content = read_to_string(&path).unwrap_or_else(|err| {
+        eprintln!("error: failed to read source file ({:?})", err);
+        exit(1);
+    });
+
+    let mut parser = Parser::new(&content);
+    let module = parser.parse_module();
+
+    if let Some(errors) = parser.errors() {
+        for error in errors {
+            eprintln!("{:?}", error);
+        }
+
+        exit(1);
+    }
+
+    println!("{:#?}", module);
 }