Contents

# frozen_string_literal: true

require_relative 'designation'
require_relative 'any_value'
require_relative 'vocabulary'

module MiniKraken
  module Core
    # Representation of a MiniKraken logical variable.
    # It is a named slot that can be associated with one value at the time.
    # In relational programming, there is no explicit assignment expression.
    # A logical variable acquire a value through an algorithm called 
    # 'unification'.
    class LogVar
      include Designation # Mixin: Acquire name attribute

      # @return [String] Internal variable name used by MiniKraken
      attr_accessor :i_name

      # Create a logical variable with given name
      # @param aName [String] The name of the variable
      def initialize(aName)
        init_designation(aName)
        @i_name = name.dup
      end

      # Indicate whether this variable is fused with another one.
      # @return [Boolean]
      def fused?
        name != i_name
      end

      # @param [Core::Vocabulary]
      def quote(env)
        raise StandardError, "class #{env}" unless env.kind_of?(Vocabulary)

        val = env.quote_ref(self)
        unless val
          result = AnyValue.new(name, env, env.names_fused(name))
        else
          result = val
        end

        result
      end
    end # class
  end # module
end # module

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
mini_kraken-0.2.04	lib/mini_kraken/core/log_var.rb