`class Builder`

A builder for constructing environments using a DSL.

Definitions

`def self.for(*facets, **values, &block)`

Create a new environment with facets and values.

Signature

parameter　facets　Array(Module): Modules to include in the environment.
parameter　values　Hash: Key-value pairs to define as methods.
parameter　block　Proc: A block for additional configuration.
returns　Module: The constructed environment module.

Implementation

def self.for(*facets, **values, &block)
	top = ::Module.new
	
	builder = self.new(top)
	
	facets.each do |facet|
		builder.include(facet)
	end
	
	values.each do |key, value|
		if value.is_a?(::Proc)
			builder.method_missing(key, &value)
		else
			builder.method_missing(key, value)
		end
	end
	
	# This allows for a convenient syntax, e.g.:
	#
	# 	Builder.for do
	# 		foo 42
	# 	end
	#
	# or:
	#
	# 	Builder.for do |builder|
	# 		builder.foo 42
	# 	end 
	if block_given?
		if block.arity == 0
			builder.instance_exec(&block)
		else
			yield builder
		end
	end
	
	return top
end

`def initialize(facet = ::Module.new)`

Initialize a new builder.

Signature

parameter　facet　Module: The module to build into, defaults to a new Module.

Implementation

def initialize(facet = ::Module.new)
	@facet = facet
end

`def include(target)`

Include a module or other includable object into the environment.

Signature

parameter　target　Module: The module to include.

Implementation

def include(target)
	if target.class == ::Module
		@facet.include(target)
	elsif target.respond_to?(:included)
		target.included(@facet)
	else
		::Kernel.raise ::ArgumentError, "Cannot include #{target.inspect} into #{@facet.inspect}!"
	end
end

`def method_missing(name, argument = nil, &block)`

Define methods dynamically on the environment.

Signature

parameter　name　Symbol: The method name to define.
parameter　argument　Object: The value to return from the method.
parameter　block　Proc: A block to use as the method implementation.

Implementation

def method_missing(name, argument = nil, &block)
	if block
		@facet.define_method(name, &block)
	else
		@facet.define_method(name){argument}
	end
end