1  # coding: utf-8
   2  # frozen_string_literal: true
   3 
   4 
   5 
   6  module Umu
   7 
   8  module Value
   9 
  10  module Core
  11 
  12  module Product
  13 
  14  class Abstract < Object
  15      include Enumerable
  16 
  17      attr_reader :fst_obj, :snd_obj, :tail_objs
  18 
  19 
  20      def initialize(fst_obj, snd_obj, tail_objs)
  21          ASSERT.kind_of fst_obj,   ::Object
  22          ASSERT.kind_of snd_obj,   ::Object
  23          ASSERT.kind_of tail_objs, ::Array
  24 
  25          super()
  26 
  27          @fst_obj   = fst_obj
  28          @snd_obj   = snd_obj
  29          @tail_objs = tail_objs
  30      end
  31 
  32 
  33      def objs
  34          [self.fst_obj, self.snd_obj] + self.tail_objs
  35      end
  36 
  37 
  38      def arity
  39          2 + self.tail_objs.size
  40      end
  41 
  42 
  43      def each
  44          yield self.fst_obj
  45 
  46          yield self.snd_obj
  47 
  48          self.tail_objs.each do |obj|
  49              yield obj
  50          end
  51      end
  52 
  53 
  54      def select_by_number(sel_num, loc, env)
  55          ASSERT.kind_of sel_num,     ::Integer
  56          ASSERT.kind_of loc,         LOC::Entry
  57 
  58          value = case sel_num
  59              when 1
  60                  self.fst_obj
  61              when 2
  62                  self.snd_obj
  63              else
  64                  unless 3 <= sel_num && sel_num <= self.arity
  65                      raise X::SelectionError.new(
  66                          loc,
  67                          env,
  68                          "Selector expected 1..%d, but %d",
  69                              self.arity, sel_num
  70                      )
  71                  end
  72 
  73                  self.tail_objs[sel_num - 3]
  74              end
  75 
  76          ASSERT.kind_of value, VC::Top
  77      end
  78  end
  79 
  80  end # Umu::Value::Core::Product
  81 
  82  end # Umu::Value::Core
  83 
  84  end # Umu::Value
  85 
  86  end # Umu