zargs

name

zargs

description

Add zero-dependency argument parsing to Java CLI applications using the zargs pattern — an enum-based argument parser. Use when adding CLI argument parsing, command-line option handling, or adding options to a Java project. Triggers on "zargs", "argument parsing", "CLI arguments", "command-line options", "parse arguments", "add options", or requests to add argument/option parsing to a Java CLI application without external dependencies.

Add zero-dependency argument parsing to a Java CLI application using $ARGUMENTS. Apply all rules below.

What is zargs

zargs is a zero-dependency, enum-based argument parsing pattern for Java CLI applications. It is not a library or dependency — it is a set of conventions and code patterns to apply directly when generating argument parsing code.

• Reference: https://github.com/AdamBien/zeeds/blob/main/zargs
• Requires: Java 21+

Argument Enum Pattern

Define an enum where each constant represents a CLI option. The enum provides matching, lookup, and usage generation:

import java.util.stream.Collectors;
import java.util.stream.Stream;

public enum Arg {
    HELP("-help", "Show this help"),
    VERBOSE("-verbose", "Enable verbose output"),
    OUTPUT("-output", "Specify output file");

    final String option;
    final String description;

    Arg(String option, String description) {
        this.option = option;
        .description = description;
    }

      {
         .option.equals(value)
            || value.startsWith(.option + );
    }

     Arg  {
         Stream.of(values())
            .filter(a -> a.matches(value))
            .findFirst()
            .orElse();
    }

     String  {
         Stream.of(values())
            .map(a -> .formatted(a.option, a.description))
            .collect(Collectors.joining());
    }
}