diff --git a/ChangeLog b/ChangeLog
index 23590086e2..2a132fe2ca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+Thu Feb  5 23:56:55 2004  Tanaka Akira  <akr@m17n.org>
+
+	* lib/prettyprint.rb (PrettyPrint#seplist): added.
+
+	* lib/pp.rb (PPMethods#pp_object): use seplist.
+	  (PPMethods#pp_hash): ditto.
+	  (Array#pretty_print): ditto.
+	  (Struct#pretty_print): ditto.
+	  (MatchData#pretty_print): ditto.
+
+	* lib/set.rb (Set#pretty_print): use seplist.
+
 Wed Feb  4 22:39:46 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (rb_stat_mode): should not sign-expand, so backout.
diff --git a/lib/pp.rb b/lib/pp.rb
index 8d8e640275..81a453d9ab 100644
--- a/lib/pp.rb
+++ b/lib/pp.rb
@@ -203,10 +203,9 @@ class PP < PrettyPrint
 
     def pp_object(obj)
       object_address_group(obj) {
-        obj.pretty_print_instance_variables.each {|v|
-          v = v.to_s if Symbol === v
-          text ',' unless first?
+        seplist(obj.pretty_print_instance_variables, lambda { text ',' }) {|v|
           breakable
+          v = v.to_s if Symbol === v
           text v
           text '='
           group(1) {
@@ -219,8 +218,7 @@ class PP < PrettyPrint
 
     def pp_hash(obj)
       group(1, '{', '}') {
-        obj.each {|k, v|
-          comma_breakable unless first?
+        seplist(obj, nil, :each_pair) {|k, v|
           group {
             pp k
             text '=>'
@@ -279,8 +277,7 @@ end
 class Array
   def pretty_print(q)
     q.group(1, '[', ']') {
-      self.each {|v|
-        q.comma_breakable unless q.first?
+      q.seplist(self) {|v|
         q.pp v
       }
     }
@@ -310,8 +307,7 @@ end
 class Struct
   def pretty_print(q)
     q.group(1, '#<struct ' + self.class.name, '>') {
-      self.members.each {|member|
-        q.text "," unless q.first?
+      q.seplist(self.members, lambda { q.text "," }) {|member|
         q.breakable
         q.text member.to_s
         q.text '='
@@ -420,8 +416,7 @@ class MatchData
   def pretty_print(q)
     q.object_group(self) {
       q.breakable
-      1.upto(self.size) {|i|
-        q.breakable unless q.first?
+      q.seplist(1..self.size, lambda { q.breakable }) {|i|
         q.pp self[i-1]
       }
     }
diff --git a/lib/prettyprint.rb b/lib/prettyprint.rb
index 70b6da7924..6f2c8ea7cc 100644
--- a/lib/prettyprint.rb
+++ b/lib/prettyprint.rb
@@ -159,6 +159,19 @@ class PrettyPrint
     @group_stack.last
   end
 
+  def seplist(list, sep=nil, iter_method=:each)
+    sep ||= lambda { comma_breakable }
+    first = true
+    list.__send__(iter_method) {|*v|
+      if first
+        first = false
+      else
+        sep.call
+      end
+      yield(*v)
+    }
+  end
+
   def first?
     current_group.first?
   end
diff --git a/lib/set.rb b/lib/set.rb
index a19a4f3b55..e9c6931b14 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -418,14 +418,7 @@ class Set
   def pretty_print(pp)	# :nodoc:
     pp.text sprintf('#<%s: {', self.class.name)
     pp.nest(1) {
-      first = true
-      each { |o|
-	if first
-	  first = false
-	else
-	  pp.text ","
-	  pp.breakable
-	end
+      pp.seplist(self) { |o|
 	pp.pp o
       }
     }