# $Id: Serializer.xotcl,v 1.19 2007/10/05 09:06:00 neumann Exp $
package require XOTcl
package provide xotcl::serializer 1.0

# For the time being, we require classical XOTcl.

# TODO: separate into two packages (i.e. make one XOTcl specific
# serializer package, and (a) load this package on a load of this
# package (when ::xotcl::Object is defined), and (b) load it from
# "xotcl1.tcl", when the serializer is alreaded loaded.

namespace eval ::xotcl::serializer {

  namespace import ::nx::*

  @ @File {
    description {
      This package provides the class Serializer, which can be used to
      generate a snapshot of the current state of the workspace
      in the form of XOTcl source code.
    }
    authors {
      Gustaf Neumann, Gustaf.Neumann@wu-wien.ac.at
    }
    date { $Date: 2007/10/05 09:06:00 $ }
  }
  
  @ Serializer proc all {
		 ?-ignoreVarsRE RE? 
		 "provide regular expression; matching vars are ignored"
		 ?-ignore obj1 obj2 ...? 
		 "provide a list of objects to be omitted"} {
    Description {
      Serialize all objects and classes that are currently 
      defined (except the specified omissions and the current
	       Serializer object). 
      <p>Examples:<@br>
      <@pre class='code'>Serializer all -ignoreVarsRE {::b$}</@pre>
      Do not serialize any instance variable named b (of any object).<p>
      <@pre class='code'>Serializer all -ignoreVarsRE {^::o1::.*text.*$|^::o2::x$}</@pre>
      Do not serialize any variable of c1 whose name contains 
      the string "text" and do not serialze the variable x of o2.<p>
      <@pre class='code'>Serializer all -ignore obj1 obj2 ... </@pre>
      do not serizalze the specified objects
    }
    return "script"
  }
  
  @ Serializer proc deepSerialize {
		   ?-ignoreVarsRE&nbsp;RE? 
		   "provide regular expression; matching vars are ignored"
		   ?-ignore&nbsp;obj1&nbsp;obj2&nbsp;...? 
		   "provide a list of objects to be omitted"
		   ?-map&nbsp;list? "translate object names in serialized code"
		   objs "Objects to be serialized"
				 } {
    Description {
      Serialize object with all child objects (deep operation) 
      except the specified omissions. For the description of 
      <@tt>ignore</@tt> and <@tt>igonoreVarsRE</@tt> see 
      <@tt>Serizalizer all</@tt>. <@tt>map</@tt> can be used
      in addition to provide pairs of old-string and new-string
      (like in the tcl command <@tt>string map</@tt>). This option
      can be used to regenerate the serialized object under a different
      object or under an different name, or to translate relative
      object names in the serialized code.<p>
      
      Examples:  
      <@pre class='code'>Serializer deepSerialize -map {::a::b ::x::y} ::a::b::c</@pre>
      Serialize the object <@tt>c</@tt> which is a child of <@tt>a::b</@tt>; 
      the object will be reinitialized as object <@tt>::x::y::c</@tt>,
      all references <@tt>::a::b</@tt> will be replaced by <@tt>::x::y</@tt>.<p>
      
      <@pre class='code'>Serializer deepSerialize -map {::a::b [self]} ::a::b::c</@pre>
      The serizalized object can be reinstantiated under some current object,
      under which the script is evaluated.<p>
      
      <@pre class='code'>Serializer deepSerialize -map {::a::b::c ${var} ::a::b::c}</@pre>
      The serizalized object will be reinstantiated under a name specified
      by the variable <@tt>var<@tt> in the recreation context.
    }
    return "script"
  }
  
  @ Serializer proc methodSerialize {
		     object "object or class"
		     method "name of method"
		     prefix "either empty or 'inst' (latter for instprocs)"
				   } {
    Description {
      Serialize the specified method. In order to serialize 
      an instproc, <@tt>prefix</@tt> should be 'inst'; to serialze
      procs, it should be empty.<p> 
      
      Examples:
      <@pre class='code'>Serializer methodSerialize Serializer deepSerialize ""</@pre>
      This command serializes the proc <@tt>deepSerialize</@tt> 
      of the Class <@tt>Serializer</@tt>.<p>
      
      <@pre class='code'>Serializer methodSerialize Serializer serialize inst</@pre>
      This command serializes the instproc <@tt>serialize</@tt> 
      of the Class <@tt>Serializer</@tt>.<p>
    }
    return {Script, which can be used to recreate the specified method}
  }
  @ Serializer proc exportMethods {
	list "list of methods of the form 'object proc|instproc methodname'" 
      } {
    Description {
      This method can be used to specify methods that should be
      exported in every <@tt>Serializer all<@/tt>. The rationale
      behind this is that the serializer does not serialize objects
      from the ::xotcl:: namespace, which is used for XOTcl internals
      and volatile objects. It is however often useful to define
      methods on ::xotcl::Class or ::xotcl::Objects, which should
      be exported. One can export procs, instprocs, forward and instforward<p>
      Example:
      <@pre class='code'>      Serializer exportMethods {
	::xotcl::Object instproc __split_arguments
	::xotcl::Object instproc __make_doc
	::xotcl::Object instproc ad_proc
	::xotcl::Class  instproc ad_instproc
	::xotcl::Object forward  expr
      }<@/pre>
    }
  }
  
  
  @ Serializer instproc serialize {entity "Object or Class"} {
    Description {
      Serialize the specified object or class.
    }
    return {Object or Class with all currently defined methods, 
      variables, invariants, filters and mixins}
  }

  ###########################################################################
  # Serializer Class, independent from Object System
  ###########################################################################

  Class create Serializer -parameter {ignoreVarsRE} {
    
    :method ignore args {
      # Ignore the objects passed via args.
      # :skip is used for filtering only in the topological sort.
      foreach element $args { 
        foreach o [Serializer allChildren $element] {
          set :skip($o) 1
        }
      }
    }
    
    :method init {} {
      # Never serialize the (volatile) serializer object
      :ignore [self]
    }

    :method warn msg {
      if {[info command ns_log] ne ""} {
        ns_log Notice $msg
      } else {
        puts stderr "!!! $msg"
      }
    }

    :method addPostCmd {cmd} {
      if {$cmd ne ""} {append :post_cmds $cmd "\n"}
    }
    
    :method setObjectSystemSerializer {o serializer} {
      set :serializer($o) $serializer
    }

    :method isExportedObject {o} {
      # Check, whether o is exported. For exported objects.
      # we export the object tree.
      set oo $o
      while {1} {
        if {[[self class] exists exportObjects($o)]} {
          return 1
        }
        # we do this for object trees without object-less namespaces
        if {![::xotcl::is $o object]} {
          return 0
        }
        set o [$o info parent]
      }
    }
    
    :method topoSort {set all} {
      if {[array exists :s]} {array unset :s}
      if {[array exists :level]} {array unset :level}

      foreach c $set {
        if {!$all &&
            [string match "::xotcl::*" $c] && 
            ![:isExportedObject $c]} continue
        if {[info exists :skip($c)]} continue
        set :s($c) 1
      }
      set stratum 0
      while {1} {
        set set [array names :s]
        if {[llength $set] == 0} break
        incr stratum
        # :warn "$stratum set=$set"
        set :level($stratum) {}
        foreach c $set {
          set oss [set :serializer($c)]
          if {[$oss needsNothing $c [self]]} {
            lappend :level($stratum) $c
          }
        }
        if {[set :level($stratum)] eq ""} {
          set :level($stratum) $set
          :warn "Cyclic dependency in $set"
        }
        foreach i [set :level($stratum)] {unset :s($i)}
      }
    }

    :method needsOneOf list {
      foreach e $list {if {[info exists :s($e)]} {return 1}}
      return 0
    }
    
    :method serialize-objects {list all} {
      set :post_cmds ""

      # register for introspection purposes "trace" under a different
      # name for every object system
      foreach oss [ObjectSystemSerializer info instances] {
        $oss registerTrace 1
      }

      :topoSort $list $all
      #foreach i [lsort [array names :level]] { :warn "$i: [set :level($i)]"}
      set result ""
      foreach l [lsort -integer [array names :level]] {
        foreach i [set :level($l)] {
          #.warn "serialize $i"
          #append result "# Stratum $l\n"
          set oss [set :serializer($i)]
          append result [$oss serialize $i [self]] \n
        }
      }
      foreach e $list {
        set namespace($e) 1
        set namespace([namespace qualifiers $e]) 1
      }
      # remove "trace" from all object systems
      foreach oss [ObjectSystemSerializer info instances] {
        $oss registerTrace 0
      }
      
      # Handling of variable traces: traces might require a 
      # different topological sort, which is hard to handle.
      # Similar as with filters, we deactivate the variable
      # traces during initialization. This happens by
      # (1) replacing the XOTcl's trace method by a no-op
      # (2) collecting variable traces through collect-var-traces
      # (3) re-activating the traces after variable initialization
      
      set exports ""
      set pre_cmds ""
      
      # delete ::xotcl from the namespace list, if it exists...
      catch {unset namespace(::xotcl)}
      foreach ns [array name namespace] {
        if {![namespace exists $ns]} continue
        if {![::xotcl::is $ns object]} {
          append pre_cmds "namespace eval $ns {}\n"
        } elseif {$ns ne [namespace origin $ns] } {
          append pre_cmds "namespace eval $ns {}\n"
        }
        set exp [namespace eval $ns {namespace export}]
        if {$exp ne ""} {
          append exports "namespace eval $ns {namespace export $exp}" \n
        }
      }
      return $pre_cmds$result${:post_cmds}$exports
    }

    :method deepSerialize o {
      # assumes $o to be fully qualified
      set instances [Serializer allChildren $o] 
      foreach oss [ObjectSystemSerializer info instances] {
        $oss registerSerializer [self] $instances
      }
      :serialize-objects $instances 1
    }

    ###############################
    # class object specfic methods
    ###############################

    :object method allChildren o {
      # return o and all its children fully qualified
      set set [::nx::core::dispatch $o -objscope ::xotcl::self]
      foreach c [$o info children] {
        lappend set {*}[:allChildren $c]
      }
      return $set
    }

    :object method exportMethods list {
      foreach {o p m} $list {set :exportMethods([list $o $p $m]) 1}
    }

    :object method exportObjects list {
      foreach o $list {set :exportObjects($o) 1}
    }

    :object method exportedMethods {} {array names :exportMethods}
    :object method exportedObjects {} {array names :exportObjects}

    :object method resetPattern {} {array unset :ignorePattern}
    :object method addPattern {p} {set :ignorePattern($p) 1}
    
    :object method checkExportedMethods {} {
      foreach k [array names :exportMethods] {
        foreach {o p m} $k break
        set ok 0
        foreach p [array names :ignorePattern] {
          if {[string match $p $o]} {
            set ok 1; break
          }
        }
        if {!$ok} {
          error "method export is only for classes in\
		[join [array names :ignorePattern] {, }] not for $o"
        }
      }
    }

    :object method checkExportedObject {} {
      foreach o [array names :exportObjects] {
        if {![::xotcl::is $o object]} {
          puts stderr "Serializer exportObject: ignore non-existing object $o"
          unset :exportObjects($o)
        } else {
          # add all child objects
          foreach o [:allChildren $element] {
            set :exportObjects($o) 1
          }
        }
      }
    }

    :object method all {-ignoreVarsRE -ignore} {

      # don't filter anything during serialization
      set filterstate [::nx::core::configure filter off]
      set s [:new -childof [self] -volatile]
      if {[info exists ignoreVarsRE]} {$s ignoreVarsRE $ignoreVarsRE}
      if {[info exists ignore]} {$s ignore $ignore}

      set r [subst {
        set ::xotcl::__filterstate \[::nx::core::configure filter off\]
        #::xotcl::Slot mixin add ::xotcl::Slot::Nocheck
        ::nx::core::configure softrecreate [::nx::core::configure softrecreate]
        ::xotcl::setExitHandler [list [::xotcl::getExitHandler]]
      }]\n
      :resetPattern
      set instances [list]
      foreach oss [ObjectSystemSerializer info instances] {
        append r [$oss serialize-all-start $s]
        lappend instances {*}[$oss instances $s]
      }

      # provide error messages for invalid exports
      :checkExportedMethods

      # export the objects and classes
      #$s warn "export objects = [array names :exportObjects]"
      #$s warn "export objects = [array names :exportMethods]"
      
      append r [$s serialize-objects $instances 0] 

      foreach oss [ObjectSystemSerializer info instances] {
        append r [$oss serialize-all-end $s]
      }

      append r {
        #::xotcl::Slot mixin delete ::xotcl::Slot::Nocheck
        ::nx::core::configure filter $::xotcl::__filterstate
        unset ::xotcl::__filterstate
      }
      ::nx::core::configure filter $filterstate
      return $r
    }

    :object method methodSerialize {object method prefix} {
      set s [:new -childof [self] -volatile]
      concat $object [$s method-serialize $object $method $prefix]
    }

    :object method deepSerialize {-ignoreVarsRE -ignore -map args} {
      :resetPattern
      set s [:new -childof [self] -volatile]
      if {[info exists ignoreVarsRE]} {$s ignoreVarsRE $ignoreVarsRE}
      if {[info exists ignore]} {$s ignore $ignore}
      
      foreach o $args {
        append r [$s deepSerialize [$o]]
      }
      if {[info exists map]} {return [string map $map $r]}
      return $r
    }

    # include Serializer in the serialized code
    :exportObjects [self]
    
  }

  
  ###########################################################################
  # Object System specific serializer
  ###########################################################################

  Class create ObjectSystemSerializer {
    
    :method init {} {
      # Include object system serializers and the meta-class in "Serializer all"
      Serializer exportObjects [self class]
      Serializer exportObjects [self]
    }

    #
    # Methods to be executed at the begin and end of serialize all
    #
    :method serialize-all-start {s} {
      :getExported
      return [:serializeExportedMethods $s]
    }

    :method serialize-all-end {s} {
      set cmd ""
      foreach o [list ${:rootClass} ${:rootMetaClass}] {
        append cmd \
            [:frameWorkCmd ::nx::core::relation $o object-mixin] \
            [:frameWorkCmd ::nx::core::relation $o class-mixin] \
            [:frameWorkCmd ::nx::core::assertion $o object-invar] \
            [:frameWorkCmd ::nx::core::assertion $o class-invar]
      }
      return $cmd
    }
    
    :method registerTrace {on} {
      if {$on} {
        ::nx::core::alias ${:rootClass}  __trace__ -objscope ::trace
      } else {
        ::nx::core::method ${:rootClass} __trace__ {} {}
      }
    }

    #
    # Handle association between objects and responsible serializers
    #
    :method registerSerializer {s instances} {
      # Communicate responsibility to serializer object $s
      foreach i $instances {
        if {![::xotcl::is $i type ${:rootClass}]} continue
        $s setObjectSystemSerializer $i [self]
      }
    }

    :method instances {s} {
      # Compute all instances, for which we are responsible and
      # notify serializer object $s
      set instances [list]
      foreach i [${:rootClass} info instances -closure] {
        if {[:matchesIgnorePattern $i] && ![info exists :exportObjects($i)]} {
          continue
        }
        $s setObjectSystemSerializer $i [self]
        lappend instances $i
      }
      #$s warn "[self] handled instances: $instances"
      return $instances
    }

    :method getExported {} {
      #
      # get exported objects and methods from main Serializer for
      # which this object specific serializer is responsible
      #
      foreach k [Serializer exportedMethods] {
        foreach {o p m} $k break
        if {[::xotcl::is $o type ${:rootClass}]} {set :exportMethods($k) 1}
      }
      foreach o [Serializer exportedObjects] {
        if {[::xotcl::is $o type ${:rootClass}]} {set :exportObjects($o) 1}
      }
      foreach p [array names :ignorePattern] {Serializer addPattern $p}
    }
    

    ###############################
    # general method serialization
    ###############################    

    :method classify {o} {
      if {[::xotcl::is $o type ${:rootMetaClass}]} \
          {return Class} {return Object}
    }

    :method collectVars o {
      set setcmd [list]
      foreach v [lsort [$o info vars]] {
        if {![info exists :ignoreVarsRE] || ![regexp [set :ignoreVarsRE] ${o}::$v]} {
          if {[$o eval [list ::array exists :$v]]} {
            lappend setcmd [list array set :$v [$o eval [list array get :$v]]]
          } else {
            lappend setcmd [list set :$v [::nx::core::setvar $o $v]]
          }
        }
      }
      return $setcmd
    }

    :method frameWorkCmd {cmd o relation -unless} {
      set v [$cmd $o $relation]
      if {$v eq ""} {return ""}
      if {[info exists unless] && $v eq $unless} {return ""}
      return [list $cmd $o $relation $v]\n
    }

    :method serializeExportedMethods {s} {
      set r ""
      foreach k [array names :exportMethods] {
        foreach {o p m} $k break
        if {![:methodExists $o $p $m]} {
          $s warn "Method does not exist: $o $p $m"
          continue
        }
        append methods($o) [:serializeExportedMethod $o $p $m]\n
      }
      foreach o [array names methods] {set ($o) 1}
      foreach o [list ${:rootClass} ${:rootMetaClass}] {
        if {[info exists ($o)]} {unset ($o)}
      }
      foreach o [concat ${:rootClass} ${:rootMetaClass} [array names ""]] {
        if {![info exists methods($o)]} continue
        append r \n $methods($o)
      }
      #puts stderr "[self] ... exportedMethods <$r\n>"
      return "$r\n"
    }

    ###############################
    # general object serialization
    ###############################

    :method serialize {objectOrClass s} {
      :[:classify $objectOrClass]-serialize $objectOrClass $s
    }

    :method matchesIgnorePattern {o} {
      foreach p [array names :ignorePattern] {
        if {[string match $p $o]} {return 1}
      }
      return 0
    }

    :method collect-var-traces {o s} {
      foreach v [$o info vars] {
        set t [$o __trace__ info variable $v]
        if {$t ne ""} {
          foreach ops $t { 
            foreach {op cmd} $ops break
            # save traces in post_cmds
            $s addPostCmd [list $o trace add variable $v $op $cmd]

            # remove trace from object
            $o trace remove variable $v $op $cmd
          }
        }
      }
    }

    ###############################
    # general dependency handling 
    ###############################

    :method needsNothing {x s} {
      return [:[:classify $x]-needsNothing $x $s]
    }

    :method Class-needsNothing {x s} {
      if {![:Object-needsNothing $x $s]} {return 0}
      set scs [$x info superclass]
      if {[$s needsOneOf $scs]} {return 0}
      if {[$s needsOneOf [::nx::core::relation $x class-mixin]]} {return 0}
      foreach sc $scs {if {[$s needsOneOf [$sc info slots]]} {return 0}}
      return 1
    }

    :method Object-needsNothing {x s} {
      set p [$x info parent]
      if {$p ne "::"  && [$s needsOneOf $p]} {return 0}
      if {[$s needsOneOf [$x info class]]}  {return 0}
      if {[$s needsOneOf [[$x info class] info slots]]}  {return 0}
      return 1
    }
    
  }

  ###########################################################################
  # next specific serializer
  ###########################################################################

  ObjectSystemSerializer create Serializer2 {
    
    set :rootClass ::nx::Object
    set :rootMetaClass ::nx::Class
    array set :ignorePattern [list "::nx::*" 1 "::xotcl::*" 1]

    :method serialize-all-start {s} {
      if {[info command ::Object] ne "" && [namespace origin ::Object] eq "::nx::Object"} {
        set intro "package require next; namespace import -force ::nx::*"
      } else {
        set intro ""
      }
      return "$intro\n[next]"
    }

    ###############################
    # next method serialization
    ###############################

    :method methodExists {object kind name} {
      expr {[$object info method type $name] != ""}
    }

    :method serializeExportedMethod {object kind name} {
      # todo: object modifier is missing
      return [:method-serialize $object $name ""]
    }

    :method method-serialize {o m modifier} {
      if {![::xotcl::is $o class]} {set modifier ""}
      return [$o {*}$modifier info method definition $m]
    }

    ###############################
    # next object serialization
    ###############################

    :method Object-serialize {o s} {
      :collect-var-traces $o $s
      append cmd [list [$o info class] create \
                      [::nx::core::dispatch $o -objscope ::xotcl::self]]

      append cmd " -noinit\n"
      foreach i [lsort [::nx::core::cmd::ObjectInfo::methods $o]] {
        append cmd [:method-serialize $o $i "object"] "\n"
      }
      append cmd \
          [list $o eval [join [:collectVars $o] "\n   "]]\n \
          [:frameWorkCmd ::nx::core::relation $o object-mixin] \
          [:frameWorkCmd ::nx::core::assertion $o object-invar]

      if {[::xotcl::is $o type ::xotcl::Slot]} {
        # Slots needs to be initialized to ensure
        # __invalidateobjectparameter to be called
        append cmd [list $o eval :init] \n
      }

      $s addPostCmd [:frameWorkCmd ::nx::core::relation $o object-filter]
      return $cmd
    }

    ###############################
    # next class serialization
    ###############################
    
    :method Class-serialize {o s} {

      set cmd [:Object-serialize $o $s]
      foreach i [lsort [::nx::core::cmd::ClassInfo::methods $o]] {
        append cmd [:method-serialize $o $i ""] "\n"
      }
      append cmd \
          [:frameWorkCmd ::nx::core::relation $o superclass -unless ${:rootClass}] \
          [:frameWorkCmd ::nx::core::relation $o class-mixin] \
          [:frameWorkCmd ::nx::core::assertion $o class-invar]
      
      $s addPostCmd [:frameWorkCmd ::nx::core::relation $o class-filter]
      return $cmd\n
    }

    # register serialize a global method
    ::nx::Object method serialize {} {
      ::Serializer deepSerialize [self]
    }
    
  }



  ###########################################################################
  # XOTcl specific serializer
  ###########################################################################

  ObjectSystemSerializer create Serializer1 {
    
    set :rootClass ::xotcl::Object
    set :rootMetaClass ::xotcl::Class
    array set :ignorePattern [list "::xotcl::*" 1]

    :method serialize-all-start {s} {
      set intro "package require XOTcl"
      if {[info command ::Object] ne "" && [namespace origin ::Object] eq "::xotcl::Object"} {
        set intro "namespace import -force ::xotcl::*"
      }
      return "$intro\n::xotcl::Object instproc trace args {}\n[next]"
    }

    :method serialize-all-end {s} {
      return "[next]\n::nx::core::alias ::xotcl::Object trace -objscope ::trace\n"
    }


    ###############################
    # XOTcl method serialization
    ###############################

    :method methodExists {object kind name} {
      switch $kind {
        proc - instproc {
          return [expr {[$object info ${kind}s $name] ne ""}]
        }
        forward - instforward {
          return [expr {[$object info ${kind} $name] ne ""}]
        }
      }
    }

    :method serializeExportedMethod {object kind name} {
      set code ""
      switch $kind {
        proc - instproc {
          if {[$object info ${kind}s $name] ne ""} {
            set prefix [expr {$kind eq "proc" ? "" : "inst"}] 
            set code [:method-serialize $object $name $prefix]\n
          }
        }
        forward - instforward {
          if {[$object info $kind $name] ne ""} {
            set code [concat [list $object] $kind $name [$object info $kind -definition $name]]\n
          }
        }
      }
      return $code
    }

    :method method-serialize {o m prefix} {
      set arglist [list]
      foreach v [$o info ${prefix}args $m] {
        if {[$o info ${prefix}default $m $v x]} {
          lappend arglist [list $v $x] } {lappend arglist $v}
      }
      lappend r $o ${prefix}proc $m \
          [concat [$o info ${prefix}nonposargs $m] $arglist] \
          [$o info ${prefix}body $m]
      foreach p {pre post} {
        if {[$o info ${prefix}$p $m] ne ""} {lappend r [$o info ${prefix}$p $m]}
      }
      return $r
    }

    ###############################
    # XOTcl object serialization
    ###############################

    :method Object-serialize {o s} {
      :collect-var-traces $o $s
      append cmd [list [$o info class] create [::nx::core::dispatch $o -objscope ::xotcl::self]]
      # slots needs to be initialized when optimized, since
      # parametercmds are not serialized
      append cmd " -noinit\n"
      foreach i [::nx::core::cmd::ObjectInfo::methods $o -methodtype scripted] {
        append cmd [:method-serialize $o $i ""] "\n"
      }
      foreach i [::nx::core::cmd::ObjectInfo::methods $o -methodtype forward] {
        append cmd [concat [list $o] forward $i [$o info forward -definition $i]] "\n"
      }
      foreach i [::nx::core::cmd::ObjectInfo::methods $o -methodtype setter] {
        append cmd [list $o parametercmd $i] "\n"
      }
      append cmd \
          [list $o eval [join [:collectVars $o] "\n   "]] \n \
          [:frameWorkCmd ::nx::core::relation $o object-mixin] \
          [:frameWorkCmd ::nx::core::assertion $o object-invar]

      $s addPostCmd [:frameWorkCmd ::nx::core::relation $o object-filter]

      return $cmd
    }

    ###############################
    # XOTcl class serialization
    ###############################
    
    :method Class-serialize {o s} {
      set cmd [:Object-serialize $o $s]
      foreach i [$o info instprocs] {
        append cmd [:method-serialize $o $i inst] "\n"
      }
      foreach i [$o info instforward] {
        append cmd [concat [list $o] instforward $i [$o info instforward -definition $i]] "\n"
      }
      foreach i [$o info instparametercmd] {
        append cmd [list $o instparametercmd $i] "\n"
      }
      # provide limited support for exporting aliases for XOTcl objects
      foreach i [::nx::core::cmd::ClassInfo::methods $o -methodtype alias] {
        set xotcl2Def [::nx::core::cmd::ClassInfo::method $o definition $i]
        set objscope   [lindex $xotcl2Def end-2]
        set methodName [lindex $xotcl2Def end-1]
        set cmdName    [lindex $xotcl2Def end]
        if {$objscope ne "-objscope"} {set objscope ""}
        append cmd [list ::nx::core::alias $o $methodName {*}$objscope $cmdName]\n
      }
      append cmd \
          [:frameWorkCmd ::nx::core::relation $o superclass -unless ${:rootClass}] \
          [:frameWorkCmd ::nx::core::relation $o class-mixin] \
          [:frameWorkCmd ::nx::core::assertion $o class-invar]

      $s addPostCmd [:frameWorkCmd ::nx::core::relation $o class-filter]
      return $cmd
    }

    # register serialize a global method for XOTcl
    ::xotcl::Object instproc serialize {} {
      ::Serializer deepSerialize [self]
    }

    
    # include this method in the serialized code
    #Serializer exportMethods {
    #  ::xotcl::Object instproc contains
    #}
  }


  namespace export Serializer
  namespace eval :: "namespace import -force [namespace current]::*"
}