[ruby-dev:16061] Re: New Struct

なかだです。

At Mon, 25 Feb 2002 12:31:28 +0900,
Shin-ichiro HARA <[e-mail]> wrote:
> で、こんなのが組み込みクラスであったら（Struct と呼べないか
> もしれないが）いいと思いません？
> 
> foo = Struct.new(:name => "matz", :age => 104)
> p foo.type #=> Struct
> p foo.name #=> "matz"
> p foo.age  #=> 104

# 年くいすぎ。:)

> もちろん name, age は特異メソッドで。

ostructがすごくそれっぽいような気がします。

そういえば、しばらく前にOpenStructでSymbolをキーに使えるように
してみたのがありました。


Index: ostruct.rb
===================================================================
RCS file: /cvs/ruby/src/ruby/lib/ostruct.rb,v
retrieving revision 1.1.1.1
diff -u -2 -p -r1.1.1.1 ostruct.rb
--- ostruct.rb	1998/01/16 12:19:17	1.1.1.1
+++ ostruct.rb	2002/01/10 11:04:36
@@ -9,47 +9,50 @@
 # p s
 
-class OpenStruct
+class OpenStruct < Hash
+  class << self
+    alias [] new
+  end
+
   def initialize(hash=nil)
-    @table = {}
     if hash
-      for k,v in hash
-	@table[k] = v
-      end
+      hash.inject(self) {|s,(k,v)| self[k.intern] = v}
     end
   end
 
   def method_missing(mid, *args)
-    mname = mid.id2name
     len = args.length
-    if mname =~ /=$/
-      if len != 1
+    if (mname = mid.to_s).sub!(/=\z/, '')
+      unless len == 1
 	raise ArgumentError, "wrong # of arguments (#{len} for 1)", caller(1)
       end
-      mname.chop!
-      @table[mname] = args[0]
+      ret = self[mname.intern] = args[0]
     elsif args.length == 0
-      @table[mname]
+      ret = self[mid]
     else
       raise NameError, "undefined method `#{mname}'", caller(1)
     end
+    mname = mname.intern
+    class << self; self; end.class_eval do
+      define_method(mname, proc {self[mname]})
+      define_method("#{mname}=", proc {|v| self[mname] = v})
+    end
+    ret
   end
-  
-  def delete_field(name)
-    if name.type == Fixnum
-      name = name.id2name
+
+  def delete(name)
+    class << self
+      remove_method(name.to_s)
+      remove_method(name.to_s+"=")
     end
-    @table.delete name
+    super name.intern
   end
+  alias delete_field delete
 
   def inspect
     str = "<#{self.type}"
-    for k,v in @table
-      str += " "
-      str += k
-      str += "="
-      str += v.inspect
+    for k,v in self
+      str << " #{k}=#{v.inspect}"
     end
-    str += ">"
-    str
+    str << ">"
   end
 end


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦