CLI: Simplify extractCommandNameArgument

Author: Geod24

source/dub/commandline.d

@@ -82,21 +82,16 @@ CommandGroup[] getCommands() @safe pure nothrow
 		args = a list of string arguments that will be processed
 
 	Returns:
-		A structure with two members. `value` is the command name
-		`remaining` is a list of unprocessed arguments
+		The command name that was found (may be null).
 */
-auto extractCommandNameArgument(string[] args)
+string commandNameArgument(ref string[] args)
 {
-	struct Result {
-		string value;
-		string[] remaining;
-	}
-
 	if (args.length >= 1 && !args[0].startsWith("-") && !args[0].canFind(":")) {
-		return Result(args[0], args[1 .. $]);
+		const result = args[0];
+		args = args[1 .. $];
+		return result;
 	}
-
-	return Result(null, args);
+	return null;
 }
 
 /// test extractCommandNameArgument usage
@@ -448,7 +443,8 @@ int runDubCommandLine(string[] args)
 
 	auto common_args = new CommandArgs(args[1..$]);
 
-	try handler.prepareOptions(common_args);
+	try
+		args = handler.prepareOptions(common_args);
 	catch (Exception e) {
 		logError("Error processing arguments: %s", e.msg);
 		logDiagnostic("Full exception: %s", e.toString().sanitize);
@@ -464,14 +460,12 @@ int runDubCommandLine(string[] args)
 
 	// extract the command
 	args = common_args.extractAllRemainingArgs();
-
-	auto command_name_argument = extractCommandNameArgument(args);
-
-	auto command_args = new CommandArgs(command_name_argument.remaining);
+	const command_name = commandNameArgument(args);
+	auto command_args = new CommandArgs(args);
 	Command cmd;
 
 	try {
-		cmd = handler.prepareCommand(command_name_argument.value, command_args);
+		cmd = handler.prepareCommand(command_name, command_args);
 	} catch (Exception e) {
 		logError("Error processing arguments: %s", e.msg);
 		logDiagnostic("Full exception: %s", e.toString().sanitize);
@@ -482,14 +476,14 @@ int runDubCommandLine(string[] args)
 	if (cmd is null) {
 		logInfoNoTag("USAGE: dub [--version] [<command>] [<options...>] [-- [<application arguments...>]]");
 		logInfoNoTag("");
-		logError("Unknown command: %s", command_name_argument.value);
+		logError("Unknown command: %s", command_name);
 		import std.algorithm.iteration : filter;
 		import std.uni : toUpper;
 		foreach (CommandGroup key; handler.commandGroups)
 		{
 			foreach (Command command; key.commands)
 			{
-				if (levenshteinDistance(command_name_argument.value, command.name) < 4) {
+				if (levenshteinDistance(command_name, command.name) < 4) {
 					logInfo("Did you mean '%s'?", command.name);
 				}
 			}