Class: Rns::Namespace

Inherits:
Object
  • Object
show all
Defined in:
lib/rns.rb

Overview

An internal class used to support Kernel#Rns in returning namespaces

Class Method Summary collapse

Class Method Details

.import(imports) ⇒ Object

Imports methods from objects into this namespace class as private instance methods.



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# File 'lib/rns.rb', line 41

def import(imports)
  ns_methods = instance_methods.map(&:to_sym)
  @_import_hash = array_to_key_value_tuples(imports).reduce({}) do |h, (obj, methods)|
    if !obj.frozen?
      raise ImportError, "#{obj} cannot be imported into Namespace because it is not frozen"
    elsif !obj.class.frozen?
      raise ImportError, "#{obj} cannot be imported into Namespace because its class is not frozen"
    end

    (methods || obj.public_methods(false)).each do |method|
      if ns_methods.include? method
        raise ImportError, "cannot override #{method} with an import"
      end
      h[method.to_sym] = obj.method(method)
    end

    h
  end

  file, line = import_call_site(caller)
  @_import_hash.each do |method, _|
    # eval is needed because:
    #   * Module#define_method can't delegate to methods that accept blocks
    #   * method_missing can, but then imported methods are available publicly
    module_eval(delegate_to_hash_source(method, :@_import_hash), file, line - 1)
    private method
  end
end