lib/raindrops/struct.rb

   1 # -*- encoding: binary -*-
   2
   3 class Raindrops::Struct
   4
   5   def self.new(*members)
   6     members = members.map { |x| x.to_sym }.freeze
   7     str = <<EOS
   8 def initialize(*values)
   9   (MEMBERS.size >= values.size) or raise ArgumentError, "too many arguments"
  10   @raindrops = Raindrops.new(MEMBERS.size)
  11   values.each_with_index { |val,i| @raindrops[i] = values[i] }
  12 end
  13
  14 def initialize_copy(src)
  15   @raindrops = src.instance_variable_get(:@raindrops).dup
  16 end
  17
  18 def []=(index, value)
  19   @raindrops[index] = value
  20 end
  21
  22 def [](index)
  23   @raindrops[index]
  24 end
  25
  26 def to_hash
  27   ary = @raindrops.to_ary
  28   rv = {}
  29   MEMBERS.each_with_index { |member, i| rv[member] = ary[i] }
  30   rv
  31 end
  32 EOS
  33
  34     members.each_with_index do |member, i|
  35       str << "def incr_#{member}; @raindrops.incr(#{i}); end; " \
  36              "def decr_#{member}; @raindrops.decr(#{i}); end; " \
  37              "def #{member}; @raindrops[#{i}]; end; " \
  38              "def #{member}=(val); @raindrops[#{i}] = val; end; "
  39     end
  40
  41     klass = Class.new
  42     klass.const_set(:MEMBERS, members)
  43     klass.class_eval(str)
  44     klass
  45   end
  46
  47 end