RubyGems.org

trope

0.0.0

# Trope **[Documentation][docs] - [Gem][gems] - [Source][source]** Prototyping language that transcompiles into pure Ruby code. 1. Build your concept in Trope. 2. Write specs. 3. Transcompile into Ruby. 4. Destroy Trope files. 5. Red, green, refactor. ## Install > NOTE: Trope is not released yet, the gem is just a placeholder. ### Bundler: `gem 'trope'` ### RubyGems: `gem install trope` ## Example Create `library.trope`: ```ruby object Book attr name <String> -!wd 'Unnamed book' attr isbn <Integer> -w attr library <Library> -w do before write { @library.books.delete(self) unless @library.nil? } after write { @library.books.push(self) unless @library.books.include?(self) } end end object Library attr books <Array> -d Array.new meth add_book do |attributes_or_book <Hash, Book>| book = attributes_or_book.is_a?(Book) ? attributes_or_book : Book.new(attributes_or_book) book.library = self @books << book end end ``` Now generate the Ruby code: ```sh $ trope compile libary.trope ``` Those 15 lines will be transcompiled into the following pure Ruby code in `library.rb`: ```ruby class Book class Error < RuntimeError; end class InvalidAttributesError < Error def to_s 'attributes must be a Hash or respond to #to_h' end end class MissingAttributeError < Error def initialize(attr_name, attr_class) @name, @class = attr_name.to_s, attr_class.to_s end def to_s "attribute '#@name' does not exist for #@class" end end class MissingNameError < Error def to_s 'name cannot be nil' end end class InvalidNameError < Error def to_s 'name must be an instance of String or respond to :to_s' end end class InvalidIsbnError < Error def to_s 'isbn must be an instance of Integer or respond to :to_i' end end class MissingLibraryError < Error def to_s 'library cannot be nil' end end class InvalidLibraryError < Error def to_s 'library must be an instance of Library' end end attr_reader *(@@_attributes = [:name, :isbn, :library]) def initialize(attributes={}) raise InvalidAttributesError unless attributes.is_a?(Hash) || attributes.respond_to?(:to_h) attributes = attributes.to_h unless attributes.is_a?(Hash) raise MissingNameError if attributes.has_key?(:name) && attributes[:name].nil? attributes[:name] = 'Unnamed book' unless attributes.has_key?(:name) attributes.each do |name, value| raise MissingAttributeError.new(name, self.class) unless @@_attributes.include?(name.to_sym) setter_method = "#{name}=" setter_method = "_#{setter_method}" unless self.class.method_defined?(setter_method) send(setter_method, value) end end def name=(value) raise MissingNameError if value.nil? raise InvalidNameError unless value.is_a?(String) || value.respond_to?(:to_s) value = value.to_i unless value.is_a?(Integer) @name = value end def isbn=(value) raise InvalidIsbnError unless value.is_a?(Integer) || value.respond_to?(:to_i) value = value.to_i unless value.is_a?(Integer) @isbn = value end def library=(value) raise InvalidLibraryError unless value.is_a?(Library) || value.nil? @library.books.delete(self) unless @library.nil? @library = value @library.books.push(self) unless @library.books.include?(self) @library end end class Library class Error < RuntimeError; end class InvalidAttributesError < Error def to_s 'attributes must be an instance of Hash or respond to #to_h' end end class MissingAttributeError < Error def initialize(attr_name, attr_class) @name, @class = attr_name.to_s, attr_class.to_s end def to_s "attribute '#@name' does not exist for #@class" end end class InvalidBooksError < Error def to_s 'books must be an instance of Array or respond to #to_a' end end attr_reader *(@@_attributes = [:books]) def initialize(attributes={}) raise InvalidAttributesError unless attributes.is_a?(Hash) || attributes.respond_to?(:to_h) attributes = attributes.to_h unless attributes.is_a?(Hash) attributes[:books] = Array.new unless attributes.has_key?(:books) attributes.each do |name, value| raise MissingAttributeError.new(name, self.class) unless @@_attributes.include?(name.to_sym) setter_method = "#{name}=" setter_method = "_#{setter_method}" unless self.class.method_defined?(setter_method) send(setter_method, value) end end def add_book(attributes_or_book={}) raise InvalidAttributesError unless attributes_or_book.is_a?(Hash) || attributes_or_book.respond_to?(:to_h) || attributes_or_book.is_a?(Book) attributes_or_book = attributes_or_book.to_h unless attributes_or_book.is_a?(Hash) || attributes_or_book.is_a?(Book) book = attributes_or_book.is_a?(Book) ? attributes_or_book : Book.new(attributes_or_book) book.library = self @books << book end protected def _books=(value) raise InvalidBooksError unless value.is_a?(Array) || value.respond_to?(:to_a) value = value.to_a unless value.is_a?(Array) @books = value end end ``` Using the transcompiled Ruby code will produce the expected results: ```ruby p library = Library.new # => #<Library:0x007fc55c0ce418 @books=[]> p library.add_book name: 'Book 1', isbn: 1 # => [#<Book:0x007fc55c0cde78 @name=0, @isbn=1, @library=#<Library:0x007fc55c0ce418 @books=[...]>>] p library # => #<Library:0x007fc55c0ce418 @books=[#<Book:0x007fc55c0cde78 @name=0, @isbn=1, @library=#<Library:0x007fc55c0ce418 ...>>]> p library.books.first # => #<Book:0x007fc55c0cde78 @name=0, @isbn=1, @library=#<Library:0x007fc55c0ce418 @books=[#<Book:0x007fc55c0cde78 ...>]>> p library.books.first.isbn = nil # => nil p library.books.first.name = nil # => Book::MissingNameError: name cannot be nil p library.books.first.library = nil # => Book::MissingLibraryError: library cannot be nil p library.books.first.isbn = ['array'] # => Book::InvalidIsbnError: isbn must be an instance of Integer or respond to :to_i p library = Library.new(books: 123) # => Library::InvalidBooksError: books must be an instance of Array or respond to #to_a ``` ### Breakdown ```ruby object Book attr name <String> -!wd 'Unnamed book' end ``` This says that I have an object `Book` that has an attribute `name` (`attr name`) that must either be an instance/subclass of `String` or be able to convert to an instance of `String` using `#to_s` (`<String>`). It is a required attribute that can never be set to nil (`!`), has a writer method (`w`), and defaults to 'Unnamed book'. The minus sign (`-`) indicates a 'switch' or 'option', must like most *nix command line programs. The example could also have been written like so: ```ruby object Book attr name <String> -! -w -d 'Unnamed book' end ``` The above examples will transcompile into the following: ```ruby class Book class Error < RuntimeError; end class InvalidAttributesError < Error def to_s 'attributes must be a Hash or respond to #to_h' end end class MissingAttributeError < Error def initialize(attr_name, attr_class) @name, @class = attr_name.to_s, attr_class.to_s end def to_s "attribute '#@name' does not exist for #@class" end end class MissingNameError < Error def to_s 'name cannot be nil' end end class InvalidNameError < Error def to_s 'name must be an instance of String or respond to :to_s' end end attr_reader *(@@_attributes = [:name]) @@_required_attributes = [:name] def initialize(attributes={}) raise InvalidAttributesError unless attributes.is_a?(Hash) || attributes.respond_to?(:to_h) attributes = attributes.to_h unless attributes.is_a?(Hash) raise MissingNameError if attributes.has_key?(:name) && attributes[:name].nil? attributes[:name] = 'Unnamed book' unless attributes.has_key?(:name) attributes.each do |name, value| raise MissingAttributeError.new(name, self.class) unless @@_attributes.include?(name.to_sym) setter_method = "#{name}=" setter_method = "_#{setter_method}" unless self.class.method_defined?(setter_method) send(setter_method, value) end end def name=(value) raise MissingNameError if value.nil? raise InvalidNameError unless value.is_a?(String) || value.respond_to?(:to_s) value = value.to_i unless value.is_a?(Integer) @name = value end end ``` ## Contributing * Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet * Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it * Fork the project * Start a feature/bugfix branch * Commit and push until you are happy with your contribution * Make sure to add tests for it. This is important so I don't break it in a future version unintentionally. * Please try not to mess with the Rakefile, VERSION, or Gemfile. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it. ## Copyright Copyright © 2012 Ryan Scott Lewis <ryan@rynet.us>. The MIT License (MIT) - See LICENSE for further details. [docs]: http://rubydoc.info/gems/trope/frames [gems]: https://rubygems.org/gems/trope [source]: https://github.com/RyanScottLewis/trope

installgem install trope
Authors

Ryan Scott Lewis

699 total downloads 699 for this version
Owners

5815438e3cb72c2e4104e835861f26b2

Gemfile
gem 'trope', '~> 0.0.0'
Versions
  1. 0.0.0 December 1, 2012 (14.5 KB)