use commandr

dub.sdl

@@ -3,4 +3,5 @@ description "A minimal D application."
 authors "tanya"
 copyright "Copyright © 2025, tanya"
 license "MPL-2.0"
+dependency "commandr" version="~>1.1.0"
 dependency "taggedalgebraic" version="~>0.11.23"

dub.selections.json

@@ -1,6 +1,7 @@
 {
 	"fileVersion": 1,
 	"versions": {
+		"commandr": "1.1.0",
 		"taggedalgebraic": "0.11.23"
 	}
 }

src/main.d

@@ -3,6 +3,8 @@ import std.file;
 import std.conv;
 import std.exception;
 
+import commandr;
+
 import token;
 import tokentype;
 import scanner;
@@ -44,12 +46,11 @@ void runPrompt(){
 }
 
 int main(string[] argv){
-	if(argv.length > 2){
-		writeln("Usage: jlox [script]");
-		return 1;
-	}
-	if(argv.length == 2)
-		runFile(argv[1]);
+	auto args = new Program("lox")
+		.add(new Argument("path").optional.acceptsFiles)
+		.parse(argv);
+	if(args.arg("path"))
+		runFile(args.arg("path"));
 	else
 		runPrompt();
 	return 0;