Results for args-functional

functional argument parsing based on callbacks that supply lists of all args

Curry functions and methods at will, reorder, define placeholders anywhere, positional and named args

Strip the first token off a string, pass remainder of string as arg to function identified by first token

Value Value is a library for defining immutable value objects in Ruby. A value object is an object whose equality to other objects is determined by its value, not its identity, think dates and amounts of money. A value object should also be immutable, as you don’t want the date “2013-04-22” itself to change but the current date to change from “2013-04-22” to “2013-04-23”. That is, you don’t want entries in a calendar for 2013-04-22 to move to 2013-04-23 simply because the current date changes from 2013-04-22 to 2013-04-23. A value object consists of one or more attributes stored in instance variables. Value sets up an #initialize method for you that let’s you set these attributes, as, value objects being immutable, this’ll be your only chance to do so. Value also adds equality checks ‹#==› and ‹#eql?› (which are themselves equivalent), a ‹#hash› method, a nice ‹#inspect› method, and a protected attribute reader for each attribute. You may of course add any additional methods that your value object will benefit from. That’s basically all there’s too it. Let’s now look at using the Value library. § Usage You create value object class by invoking ‹#Value› inside the class (module) you wish to make into a value object class. Let’s create a class that represent points on a plane: class Point Value :x, :y end A ‹Point› is thus a value object consisting of two sub-values ‹x› and ‹y› (the coordinates). Just from invoking ‹#Value›, a ‹Point› object will have a constructor that takes two arguments to set instance variables ‹@x› and ‹@y›, equality checks ‹#==› and ‹#eql?› (which are the same), a ‹#hash› method, a nice ‹#inspect› method, and two protected attribute readers ‹#x› and ‹#y›. We can thus already creat ‹Point›s: origo = Point.new(0, 0) The default of making the attribute readers protected is often good practice, but for a ‹Point› it probably makes sense to be able to access its coordinates: class Point public(*attributes) end This’ll make all attributes of ‹Point› public. You can of course choose to only make certain attributes public: class Point public :x end Note that this public is standard Ruby functionality. Adding a method to ‹Point› is of course also possible and very much Rubyish: class Point def distance(other) Math.sqrt((other.x - x)**2 + (other.y - y)**2) end end For some value object classes you might want to support optional attributes. This is done by providing a default value for the attribute, like so: class Money Value :amount, [:currency, :USD] end Here, the ‹currency› attribute will default to ‹:USD›. You can create ‹Money› via dollars = Money.new(2) but also kronor = Money.new(2, :SEK) All required attributes must come before any optional attributes. Splat attributes are also supported: class List Value :'*elements' end empty = List.new suits = List.new(:spades, :hearts, :diamonds, :clubs) Splat attributes are optional. Finally, block attributes are also available: class Block Value :'&block' end block = Block.new{ |e| e * 2 } Block attributes are optional. Comparison beyond ‹#==› is possible by specifingy the ‹:comparable› option to ‹#Value›, listing one or more attributes that should be included in the comparison: class Vector Value :a, :b, :comparable => :a end Note that equality (‹#==› and ‹#eql?›) is always defined based on all attributes, regardless of arguments to ‹:comparable›. Here we say that comparisons between ‹Vector›s should be made between the values of the ‹a› attribute only. We can also make comparisons between all attributes of a value object: class Vector Value :a, :b, :comparable => true end To sum things up, let’s use all possible arguments to ‹#Value› at once: class Method Value :file, :line, [:name, 'unnamed'], :'*args', :'&block', :comparable => [:file, :line] end A ‹Method› consists of file and line information, a possible name, some arguments, possibly a block, and is comparable on the file and line on which they appear. Check out the {full API documentation}¹ for a more explicit description, should you need it or should you want to extend it. ¹ See http://disu.se/software/value/api/ § Financing Currently, most of my time is spent at my day job and in my rather busy private life. Please motivate me to spend time on this piece of software by donating some of your money to this project. Yeah, I realize that requesting money to develop software is a bit, well, capitalistic of me. But please realize that I live in a capitalistic society and I need money to have other people give me the things that I need to continue living under the rules of said society. So, if you feel that this piece of software has helped you out enough to warrant a reward, please PayPal a donation to now@disu.se¹. Thanks! Your support won’t go unnoticed! ¹ Send a donation: https://www.paypal.com/cgi-bin/webscr?cmd=_donations&business=now%40disu%2ese&item_name=Value § Reporting Bugs Please report any bugs that you encounter to the {issue tracker}¹. ¹ See https://github.com/now/value/issues § Authors Nikolai Weibull wrote the code, the tests, the manual pages, and this README. § Licensing Value is free software: you may redistribute it and/or modify it under the terms of the {GNU Lesser General Public License, version 3}¹ or later², as published by the {Free Software Foundation}³. ¹ See http://disu.se/licenses/lgpl-3.0/ ² See http://gnu.org/licenses/ ³ See http://fsf.org/

# Rake::ToolkitProgram Create toolkit programs easily with `Rake` and `OptionParser` syntax. Bash completions and usage help are baked in. ## Installation Add this line to your application's Gemfile: ```ruby gem 'rake-toolkit_program' ``` And then execute: $ bundle Or install it yourself as: $ gem install rake-toolkit_program ## Quickstart * Shebang it up (in a file named `awesome_tool.rb`) ```ruby #!/usr/bin/env ruby ``` * Require the library ```ruby require 'rake/toolkit_program' ``` * Make your life easier ```ruby Program = Rake::ToolkitProgram ``` * Define your command tasks ```ruby Program.command_tasks do desc "Build it" task 'build' do # Ruby code here end desc "Test it" task 'test' => ['build'] do # Rake syntax ↑↑↑↑↑↑↑ for dependencies # Ruby code here end end ``` You can use `Program.args` in your tasks to access the other arguments on the command line. For argument parsing integrated into the help provided by the program, see the use of `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` below. * Wire the mainline ```ruby Program.run(on_error: :exit_program!) if $0 == __FILE__ ``` * In the shell, prepare to run the program (UNIX/Linux systems only) ```console $ chmod +x awesome_tool.rb $ ./awesome_tool.rb --install-completions Completions installed in /home/rtweeks/.bashrc Source /home/rtweeks/.bash-complete/awesome_tool.rb-completions for immediate availability. $ source /home/rtweeks/.bash-complete/awesome_tool.rb-completions ``` * Ask for help ```console $ ./awesome_tool.rb help *** ./awesome_tool.rb Toolkit Program *** . . . ``` ## Usage Let's look at a short sample toolkit program -- put this in `awesome.rb`: ```ruby #!/usr/bin/env ruby require 'rake/toolkit_program' require 'ostruct' ToolkitProgram = Rake::ToolkitProgram ToolkitProgram.title = "My Awesome Toolkit of Awesome" ToolkitProgram.command_tasks do desc <<-END_DESC.dedent Fooing myself I'm not sure what I'm doing, but I'm definitely fooing! END_DESC task :foo do a = ToolkitProgram.args puts "I'm fooed#{' on a ' if a.implement}#{a.implement}" end.parse_args(into: OpenStruct.new) do |parser, args| parser.no_positional_args! parser.on('-i', '--implement IMPLEMENT', 'An implement on which to be fooed') do |val| args.implement = val end end end if __FILE__ == $0 ToolkitProgram.run(on_error: :exit_program!) end ``` Make sure to `chmod +x awesome.rb`! What does this support? $ ./awesome.rb foo I'm fooed $ ./awesome.rb --help *** My Awesome Toolkit of Awesome *** Usage: ./awesome.rb COMMAND [OPTION ...] Avaliable options vary depending on the command given. For details of a particular command, use: ./awesome.rb help COMMAND Commands: foo Fooing myself help Show a list of commands or details of one command Use help COMMAND to get more help on a specific command. $ ./awesome.rb help foo *** My Awesome Toolkit of Awesome *** Usage: ./awesome.rb foo [OPTION ...] Fooing myself I'm not sure what I'm doing, but I'm definitely fooing! Options: -i, --implement IMPLEMENT An implement on which to be fooed $ ./awesome.rb --install-completions Completions installed in /home/rtweeks/.bashrc Source /home/rtweeks/.bash-complete/awesome.rb-completions for immediate availability. $ source /home/rtweeks/.bash-complete/awesome.rb-completions $ ./awesome.rb <tab><tab> foo help $ ./awesome.rb f<tab> ↳ ./awesome.rb foo $ ./awesome.rb foo <tab> ↳ ./awesome.rb foo -- $ ./awesome.rb foo --<tab><tab> --help --implement $ ./awesome.rb foo --i<tab> ↳ ./awesome.rb foo --implement $ ./awesome.rb foo --implement <tab><tab> --help awesome.rb $ ./awesome.rb foo --implement spoon I'm fooed on a spoon ### Defining Toolkit Commands Just define tasks in the block of `Rake::ToolkitProgram.command_tasks` with `task` (i.e. `Rake::DSL#task`). If `desc` is used to provide a description, the task will become visible in help and completions. When a command task is initially defined, positional arguments to the command are available as an `Array` through `Rake::ToolkitProgram.args`. ### Option Parsing This gem extends `Rake::Task` with a `#parse_args` method that creates a `Rake::ToolkitProgram::CommandOptionParser` (derived from the standard library's `OptionParser`) and an argument accumulator and `yield`s them to its block. * The arguments accumulated through the `Rake::ToolkitProgram::CommandOptionParser` are available to the task in `Rake::ToolkitProgram.args`, replacing the normal `Array` of positional arguments. * Use the `into:` keyword of `#parse_args` to provide a custom argument accumulator object for the associated command. The default argument accumulator constructor can be defined with `Rake::ToolkitProgram.default_parsed_args`. Without either of these, the default accumulator is a `Hash`. * Options defined using `OptionParser#on` (or any of the variants) will print in the help for the associated command. ### Positional Arguments Accessing positional arguments given after the command name depends on whether or not `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` has been called on the command task. If this method is not called, positional arguments will be an `Array` accessible through `Rake::ToolkitProgram.args`. When `Rake::Task(Rake::ToolkitProgram::TaskExt)#parse_args` is used: * `Rake::ToolkitProgram::CommandOptionParser#capture_positionals` can be used to define how positional arguments are accumulated. * If the argument accumulator is a `Hash`, the default (without calling this method) is to assign the `Array` of positional arguments to the `nil` key of the `Hash`. * For other types of accumulators, the positional arguments are only accessible if `Rake::ToolkitProgram::CommandOptionParser#capture_positionals` is used to define how they are captured. * If a block is given to this method, the block of the method will receive the `Array` of positional arguments. If it is passed an argument value, that value is used as the key under which to store the positional arguments if the argument accumulator is a `Hash`. * `Rake::ToolkitProgram::CommandOptionParser#expect_positional_cardinality` can be used to set a rule for the count of positional arguments. This will affect the _usage_ presented in the help for the associated command. * `Rake::ToolkitProgram::CommandOptionParser#map_positional_args` may be used to transform (or otherwise process) positional arguments one at a time and in the context of options and/or arguments appearing earlier on the command line. ### Convenience Methods * `Rake::Task(Rake::ToolkitProgram::TaskExt)#prohibit_args` is a quick way, for commands that accept no options or positional arguments, to declare this so the help and bash completions reflect this. It is equivalent to using `#parse_args` and telling the parser `parser.expect_positional_cardinality(0)`. * `Rake::ToolkitProgram::CommandOptionParser#no_positional_args!` is a shortcut for calling `#expect_positional_cardinality(0)` on the same object. * `Rake::Task(Rake::ToolkitProgram::TaskExt)#invalid_args!` and `Rake::ToolkitProgram::CommandOptionParser#invalid_args!` are convenient ways to raise `Rake::ToolkitProgram::InvalidCommandLine` with a message. ## OptionParser in Rubies Before and After v2.4 The `OptionParser` class was extended in Ruby 2.4 to simplify capturing options into a `Hash` or other container implementing `#[]=` in a similar way. This gem supports that, but it means that behavior varies somewhat between the pre-2.4 era and the 2.4+ era. To have consistent behavior across that version change, the recommendation is to use a `Struct`, `OpenStruct`, or custom class to hold program options rather than `Hash`. ## Development After checking out the repo, run `bin/setup` to install dependencies. You can also run `bin/console` for an interactive prompt that will allow you to experiment. To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org). To run the tests, use `rake`, `rake test`, or `rspec spec`. Tests can only be run on systems that support `Kernel#fork`, as this is used to present a pristine and isolated environment for setting up the tool. If run using Ruby 2.3 or earlier, some tests will be pending because functionality expects Ruby 2.4's `OptionParser`. ## Contributing Bug reports and pull requests are welcome on GitHub at https://github.com/PayTrace/rake-toolkit_program. For further details on contributing, see [CONTRIBUTING.md](./CONTRIBUTING.md).

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