lib/open_classes/array.rb in tbpgr_utils-0.0.16 vs lib/open_classes/array.rb in tbpgr_utils-0.0.17

@@ -62,20 +62,22 @@
     ret
   end
 
   # Arrays loop together select.
   #
+  # together_select has aliases [:tselect, :together_find_all, :tfindall]
+  #
   # if you want to single Array return
   #   firsts = [1, 2, 3, 4]
   #   seconds =  [4, 2, 3, 1]
   #   ret = [firsts, seconds].together_select{|first, second|first == second}
   #   print ret # => output  [[2, 3], [2, 3]]
   #
   # if you want to multi Array return
   #   firsts = [1, 2, 3, 4]
   #   seconds =  [4, 2, 3, 1]
-  #   ret = [firsts, seconds].together_select{|first, second|[first.odd?, second.even?}
+  #   ret = [firsts, seconds].together_select{|first, second|[first.odd?, second.even?]}
   #   print ret # => output  [[1, 3], [4, 2]]
   def together_select
     if_not_contain_array_rails_type_error
     ret = []
     first.each_with_index do |i_v, i|
@@ -84,12 +86,56 @@
       ret = set_together_each_return_select(ret, each_ret, i)
     end
     ret
   end
 
+  # Arrays loop together reduce.
+  #
+  # together_reduce has aliases [:treduce, :together_inject, :tinject]
+  #
+  # if you want to single return
+  #   firsts = [1, 2, 3, 4]
+  #   seconds =  [4, 2, 3, 1]
+  #   ret = [firsts, seconds].together_reduce{|memo, first, second|memo + first + second}
+  #   print ret # => output  20
+  #
+  # if you want to single return with init value
+  #   firsts = [1, 2, 3, 4]
+  #   seconds =  [4, 2, 3, 1]
+  #   ret = [firsts, seconds].together_reduce(10){|memo, first, second|memo + first + second}
+  #   print ret # => output  30
+  #
+  # if you want to single return with init string value
+  #   firsts = %w{a b c}
+  #   seconds =  %w{1 2 3}
+  #   ret = [firsts, seconds].together_reduce('start-'){|memo, first, second|memo + first + second}
+  #   print ret # => output 'start-a1b2c3'
+  #
+  # if you want to single return with init Array value
+  #   firsts = [1, 2, 3, 4]
+  #   seconds =  [4, 2, 3, 1]
+  #   ret = [firsts, seconds].together_reduce([]){|memo, first, second|memo << first + second}
+  #   print ret # => output [5, 4, 6, 5]
+  #
+  # if you want to single return with init Hash value
+  #   firsts = [1, 2, 3, 4]
+  #   seconds =  [4, 2, 3, 1]
+  #   ret = [firsts, seconds].together_reduce({}){|memo, first, second|memo[first] = second;memo}
+  #   print ret # => output {1=>4, 2=>2, 3=>3, 4=>1}
+  def together_reduce(init = nil)
+    if_not_contain_array_rails_type_error
+    memo = initial_memo init
+    first.each_with_index do |i_v, i|
+      eval_each_str = get_args_str_for_together i
+      memo = instance_eval "yield(memo, #{eval_each_str})"
+    end
+    memo
+  end
+
   alias_methods [:together_collect, :tmap, :tcollect], :together_map
   alias_methods [:together_find_all, :tselect, :tfindall], :together_select
+  alias_methods [:together_inject, :treduce, :tinject], :together_reduce
 
   private
 
   def if_not_contain_array_rails_type_error
     each { |f|fail TypeError, "you have to use [Array1, Array2, ...] | #{f.class} is invalid" unless f.class == Array }
@@ -123,9 +169,14 @@
       each_ret = tmp_each_ret
     end
     size.times { |i|ret << [] } if index == 0
     (0..(size - 1)).each { |i|ret[i] << self[i][index] if each_ret[i] }
     ret
+  end
+
+  def initial_memo(init)
+    return init unless init.nil?
+    first.first.is_a?(Numeric) ? 0 : first.first.is_a?(String) ? '' : nil
   end
 
   def together_return_multi?(list)
     (list.class == Array && list.size == size).to_bool
   end