What is it?
With Dialekt you can easily define properties for DSL objects that support nice accessor methods, type checking and transformation.
Dialekt is based on Docile, which is a great tool to create DSLs in Ruby. However, you will soon find yourself creating lots of repetetive code to implement your DSL accessors. Dialekt aims to simplify this task.
Example
Let's assume you want to create a build tool called Backscratcher (sort of a small rake to scratch an itch :-) that uses a DSL for configuration. Your tool supports tasks and dependencies between tasks, and tasks can be grouped into namespaces. You start by creating a model and using Dialekt to define the properties.
require "dialekt"
require "forwardable"
module Backscratcher
extend Forwardable
class Task
attr_reader :name
# Create a set property containing strings
dsl_set :dependencies, value_type: String
def initialize(name:)
@name = name
end
end
class FileTask < Task
end
class Namespace
attr_reader :name
# Create a tasks hash with string keys
dsl_map :tasks, key_type: String, value_type: Task do
# Create an accessor for task entries
entry :task, value_factory: ->(key:) { Task.new(name: key) }
# Create an accessor for file task entries
entry :file, value_type: FileTask, value_factory: ->(key:) { FileTask.new(name: key) }
end
# Create a namespace hash with string keys
dsl_map :namespaces, key_type: String, value_type: Namespace do
# Create an accessor for namespace entries
entry :namespace, value_factory: ->(key:) { Namespace.new(name: key) }
end
def initialize(name:)
@name = name
@namespaces = {}
@tasks = {}
end
end
# Make some methods available in the root namespace for convenience
def_delegators :root, :namespace, :task, :file
def root
@root ||= Namespace.new(name: "")
end
end
include BackscratcherYou now have a DSL for your build tool giving you methods to create namespaces, tasks and dependencies. Dialekt will handle the definition of accessores, type checking, creating new collection entries and applying DSL configurations:
task "build" do
dependency "db:create"
dependency "db:load"
end
file "test.txt"
namespace "db" do
task "create"
task "load" do
dependencies ["db:create"]
end
end