Kebab

WIP. Public API is subject to change.

Installation

Add the dependency to your shard.yml:

dependencies:
  kebab:
    github: DanielGilchrist/kebab

Then run shards install.

Quick example

require "kebab"

@[Kebab::Command(summary: "Greet someone")]
struct Greet
  include Kebab::Parseable

  @[Kebab::Argument(description: "Name to greet")]
  getter name : String

  @[Kebab::Option(short: 'l', description: "Make it loud")]
  getter? loud : Bool = false
end

case result = Greet.parse # args default to ARGV
in Greet
  message = "Hello, #{result.name}!"
  message = message.upcase if result.loud?
  puts message
in Kebab::Help
  puts result        # the user passed --help
in Kebab::Errors
  STDERR.puts result # parsing failed
  exit(1)
end

When a command owns its logic, give it a def run and dispatch with Type.run, which parses, runs on success, and writes help and errors for you.

Examples

Runnable walkthroughs in examples/:

• examples/parsing/: kebab as a pure parser, no def run.
• examples/command/: single-command pattern with Type.run.
• examples/subcommands/: multi-level command tree.
• examples/errors/: typed error dispatch in parsing mode.
• examples/suggestions/: in-command error handlers with "did you mean" hints.
• examples/completions/: generating fish, bash, and zsh completions.
• examples/global/: options usable anywhere in a command's subtree with global: true.
• examples/collections/: repeated options, value groups, converters, and variadic arity.
• examples/counting/: counting flag occurrences with count: true, like -vvv.
• examples/testing/: testing commands with parse, injected dependencies, and captured IO.

API docs

Generate them with crystal docs from the repo root.