https://github.com/woodruffw/dreck

A stupid parser for trailing arguments.
https://github.com/woodruffw/dreck

argument-parser option-parser ruby type-checking

Last synced: 13 days ago
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A stupid parser for trailing arguments.

• Host: GitHub
• URL: https://github.com/woodruffw/dreck
• Owner: woodruffw
• License: other
• Created: 2017-06-22T05:17:48.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2020-11-09T00:46:35.000Z (about 4 years ago)
• Last Synced: 2024-12-19T10:17:29.043Z (15 days ago)
• Topics: argument-parser, option-parser, ruby, type-checking
• Language: Ruby
• Homepage: https://rubygems.org/gems/dreck
• Size: 38.1 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
dreck

=====

![license](https://raster.shields.io/badge/license-MIT%20with%20restrictions-green.png)

[![Build Status](https://img.shields.io/github/workflow/status/woodruffw/dreck/CI/master)](https://github.com/woodruffw/dreck/actions?query=workflow%3ACI)

[![Gem Version](https://badge.fury.io/rb/dreck.svg)](https://badge.fury.io/rb/dreck)

A stupid parser for trailing arguments.

### Motivation

There are lots of good argument parsers for Ruby:

[OptionParser](https://ruby-doc.org/stdlib/libdoc/optparse/rdoc/OptionParser.html),

[Slop](https://github.com/leejarvis/slop), [trollop](https://manageiq.github.io/trollop/),

[cocaine](https://github.com/thoughtbot/cocaine), etc.

Most of these are great for parsing and typechecking options, but none provide a good

interface to the arguments that often *trail* the options.

Dreck does exactly that. Give it a specification of arguments (and their

types) to expect, and it will give you a nicely typechecked result.

### Installation

```bash

$ gem install dreck

```

### Usage

Dreck is best used in conjunction with an option parser like

[Slop](https://github.com/leejarvis/slop), which can provide an array of

arguments with options already filtered out:

```ruby

opts = Slop.parse do |s|

  # ...

end

opts.args # => [ "/dev/urandom", "/dev/sda", "512" ]

results = Dreck.parse opts.args, strict: true do

  file   :input

  symbol :output

  int    :blocksize

end

results[:input] # => "/dev/urandom"

results[:output] # => :"/dev/sda"

results[:blocksize] # => 512

```

Lists are also supported:

```ruby

result = Dreck.parse opts.args do

  string :uuid

  list   :file, :inputs, count: 2

  list   :int, :nums

end

result[:uuid] # => "01aa84ab-5b2c-4861-adc9-fcc6990a5ca5"

result[:inputs] # => ["/tmp/foo", "/tmp/bar"]

result[:nums] # => [1, 2, 3, 4, 5]

```

### TODO

* Guarding against multiple unbound lists/unbound list before scalar types

* Custom types?