Index: generic/predefined.h
===================================================================
diff -u -r05f4b42f7615ea410b7ac33093f5b8382ce7e8c5 -r48d5751e9aeb6a4f388f6531a9248c1847b22cae
--- generic/predefined.h	(.../predefined.h)	(revision 05f4b42f7615ea410b7ac33093f5b8382ce7e8c5)
+++ generic/predefined.h	(.../predefined.h)	(revision 48d5751e9aeb6a4f388f6531a9248c1847b22cae)
@@ -146,40 +146,39 @@
 "::xotcl2::Class create ::xotcl::MetaSlot\n"
 "::xotcl::relation ::xotcl::MetaSlot superclass ::xotcl2::Class\n"
 "::xotcl::MetaSlot create ::xotcl::Slot\n"
+"::xotcl::MetaSlot create ::xotcl::ObjectParameterSlot\n"
+"::xotcl::relation ::xotcl::ObjectParameterSlot superclass ::xotcl::Slot\n"
 "::xotcl::MetaSlot __invalidateobjectparameter\n"
-"proc ::xotcl::parameterFromSlot {slot name} {\n"
+"::xotcl::ObjectParameterSlot method toParameterSyntax {name} {\n"
 "set objparamdefinition $name\n"
 "set methodparamdefinition \"\"\n"
 "set objopts [list]\n"
 "set methodopts [list]\n"
-"if {[$slot exists required] && [$slot required]} {\n"
+"if {[info exists :required] && ${:required}} {\n"
 "lappend objopts required\n"
 "lappend methodopts required}\n"
-"if {[$slot exists type]} {\n"
-"set type [$slot type]\n"
-"if {[string match ::* $type]} {\n"
-"lappend objopts object type=$type\n"
-"lappend methodopts object type=$type} else {\n"
-"lappend objopts $type\n"
-"lappend methodopts $type}}\n"
-"if {[$slot exists multivalued] && [$slot multivalued]} {\n"
-"if {!([$slot exists type] && [$slot type] eq \"relation\")} {\n"
+"if {[info exists :type]} {\n"
+"if {[string match ::* ${:type}]} {\n"
+"lappend objopts object type=${:type}\n"
+"lappend methodopts object type=${:type}} else {\n"
+"lappend objopts ${:type}\n"
+"lappend methodopts ${:type}}}\n"
+"if {[info exists :multivalued] && ${:multivalued}} {\n"
+"if {!([info exists :type] && ${:type} eq \"relation\")} {\n"
 "lappend objopts multivalued} else {}}\n"
-"if {[$slot exists arg]} {\n"
-"lappend objopts arg=[$slot arg]\n"
-"lappend methodopts arg=[$slot arg]}\n"
-"if {[$slot exists default]} {\n"
-"set arg [::xotcl::setinstvar $slot default]\n"
+"if {[info exists :arg]} {\n"
+"lappend objopts arg=${:arg}\n"
+"lappend methodopts arg=${:arg}}\n"
+"if {[info exists :default]} {\n"
+"set arg ${:default}\n"
 "if {[string match {*\\[*\\]*} $arg]} {\n"
-"lappend objopts substdefault}} elseif {[$slot exists initcmd]} {\n"
-"set arg [::xotcl::setinstvar $slot initcmd]\n"
+"lappend objopts substdefault}} elseif {[info exists :initcmd]} {\n"
+"set arg ${:initcmd}\n"
 "lappend objopts initcmd}\n"
-"if {[$slot exists methodname]} {\n"
-"set methodname [$slot methodname]\n"
-"set slotname [$slot name]\n"
-"if {$methodname ne $slotname} {\n"
-"lappend objopts arg=$methodname\n"
-"lappend methodopts arg=$methodname}}\n"
+"if {[info exists :methodname]} {\n"
+"if {${:methodname} ne ${:name}} {\n"
+"lappend objopts arg=${:methodname}\n"
+"lappend methodopts arg=${:methodname}}}\n"
 "if {[llength $objopts] > 0} {\n"
 "append objparamdefinition :[join $objopts ,]}\n"
 "if {[llength $methodopts] > 0} {\n"
@@ -189,12 +188,11 @@
 "return [list oparam $objparamdefinition mparam $methodparamdefinition]}\n"
 "proc ::xotcl::parametersFromSlots {obj} {\n"
 "set parameterdefinitions [list]\n"
-"set slots [::xotcl2::objectInfo slotobjects $obj]\n"
-"foreach slot $slots {\n"
+"foreach slot [::xotcl2::objectInfo slotobjects $obj] {\n"
 "if {[::xotcl::is $obj type ::xotcl::Object] &&\n"
 "([$slot name] eq \"mixin\" || [$slot name] eq \"filter\")} continue\n"
 "set name [namespace tail $slot]\n"
-"array set \"\" [::xotcl::parameterFromSlot $slot $name]\n"
+"array set \"\" [$slot toParameterSyntax $name]\n"
 "lappend parameterdefinitions -$(oparam)}\n"
 "return $parameterdefinitions}\n"
 "::xotcl2::Object protected method objectparameter {} {\n"
@@ -207,6 +205,7 @@
 "arg:initcmd,optional\n"
 "return $parameterdefinitions}\n"
 "::xotcl::MetaSlot create ::xotcl::MethodParameterSlot\n"
+"::xotcl::relation ::xotcl::MethodParameterSlot superclass ::xotcl::Slot\n"
 "foreach cmd [info command ::xotcl::cmd::MethodParameterSlot::*] {\n"
 "::xotcl::alias ::xotcl::MethodParameterSlot [namespace tail $cmd] $cmd}\n"
 "::xotcl::MethodParameterSlot create ::xotcl::methodParameterSlot\n"
@@ -215,7 +214,7 @@
 "::xotcl2::Object create ${class}::slot}\n"
 "foreach att $definitions {\n"
 "if {[llength $att]>1} {foreach {att default} $att break}\n"
-"::xotcl::Slot create ${class}::slot::$att\n"
+"::xotcl::ObjectParameterSlot create ${class}::slot::$att\n"
 "if {[info exists default]} {\n"
 "::xotcl::setinstvar ${class}::slot::$att default $default\n"
 "unset default}\n"
@@ -231,42 +230,43 @@
 "unset default}}\n"
 "$class __invalidateobjectparameter}\n"
 "createBootstrapAttributeSlots ::xotcl::Slot {\n"
+"{name}\n"
+"{multivalued false}\n"
+"{required false}\n"
+"default\n"
+"type}\n"
+"createBootstrapAttributeSlots ::xotcl::ObjectParameterSlot {\n"
 "{name \"[namespace tail [::xotcl::self]]\"}\n"
 "{methodname}\n"
 "{domain \"[lindex [regexp -inline {^(.*)::slot::[^:]+$} [::xotcl::self]] 1]\"}\n"
 "{defaultmethods {get assign}}\n"
 "{manager \"[::xotcl::self]\"}\n"
-"{multivalued false}\n"
-"{per-object false}\n"
-"{forward-per-object}\n"
-"{required false}\n"
-"default\n"
-"type}\n"
-"::xotcl::alias ::xotcl::Slot get ::xotcl::setinstvar\n"
-"::xotcl::alias ::xotcl::Slot assign ::xotcl::setinstvar\n"
-"::xotcl::Slot public method add {obj prop value {pos 0}} {\n"
+"{per-object false}}\n"
+"::xotcl::alias ::xotcl::ObjectParameterSlot get ::xotcl::setinstvar\n"
+"::xotcl::alias ::xotcl::ObjectParameterSlot assign ::xotcl::setinstvar\n"
+"::xotcl::ObjectParameterSlot public method add {obj prop value {pos 0}} {\n"
 "if {![set :multivalued]} {\n"
 "error \"Property $prop of [set :domain]->$obj ist not multivalued\"}\n"
 "if {[$obj exists $prop]} {\n"
 "::xotcl::setinstvar $obj $prop [linsert [::xotcl::setinstvar $obj $prop] $pos $value]} else {\n"
 "::xotcl::setinstvar $obj $prop [list $value]}}\n"
-"::xotcl::Slot public method delete {-nocomplain:switch obj prop value} {\n"
+"::xotcl::ObjectParameterSlot public method delete {-nocomplain:switch obj prop value} {\n"
 "set old [::xotcl::setinstvar $obj $prop]\n"
 "set p [lsearch -glob $old $value]\n"
 "if {$p>-1} {::xotcl::setinstvar $obj $prop [lreplace $old $p $p]} else {\n"
 "error \"$value is not a $prop of $obj (valid are: $old)\"}}\n"
-"::xotcl::Slot method unknown {method args} {\n"
+"::xotcl::ObjectParameterSlot method unknown {method args} {\n"
 "set methods [list]\n"
 "foreach m [:info callable] {\n"
 "if {[::xotcl2::Object info callable $m] ne \"\"} continue\n"
 "if {[string match __* $m]} continue\n"
 "lappend methods $m}\n"
 "error \"Method '$method' unknown for slot [::xotcl::self]; valid are: {[lsort $methods]]}\"}\n"
-"::xotcl::Slot public method destroy {} {\n"
+"::xotcl::ObjectParameterSlot public method destroy {} {\n"
 "if {${:domain} ne \"\" && [::xotcl::is ${:domain} object]} {\n"
 "${:domain} __invalidateobjectparameter}\n"
 "next}\n"
-"::xotcl::Slot method init {args} {\n"
+"::xotcl::ObjectParameterSlot protected method init {args} {\n"
 "if {${:domain} eq \"\"} {\n"
 "set :domain [::xotcl::self callingobject]}\n"
 "if {${:domain} ne \"\"} {\n"
@@ -283,7 +283,7 @@
 "{multivalued true}\n"
 "{type relation}\n"
 "{elementtype ::xotcl2::Class}}\n"
-"::xotcl::relation ::xotcl::RelationSlot superclass ::xotcl::Slot\n"
+"::xotcl::relation ::xotcl::RelationSlot superclass ::xotcl::ObjectParameterSlot\n"
 "::xotcl::alias ::xotcl::RelationSlot assign ::xotcl::relation\n"
 "::xotcl::RelationSlot protected method init {} {\n"
 "if {${:type} ne \"relation\"} {\n"
@@ -322,26 +322,44 @@
 "::xotcl::alias           ${os}::Class::slot::superclass assign ::xotcl::relation\n"
 "::xotcl::RelationSlot create ${os}::Object::slot::class -multivalued false\n"
 "::xotcl::alias           ${os}::Object::slot::class assign ::xotcl::relation\n"
-"::xotcl::RelationSlot create ${os}::Object::slot::mixin \\\n"
-"-methodname object-mixin\n"
-"::xotcl::RelationSlot create ${os}::Object::slot::filter \\\n"
-"-elementtype \"\"\n"
-"::xotcl::RelationSlot create ${os}::Class::slot::mixin \\\n"
-"-methodname class-mixin\n"
-"::xotcl::RelationSlot create ${os}::Class::slot::filter \\\n"
+"::xotcl::RelationSlot create ${os}::Object::slot::mixin -methodname object-mixin\n"
+"::xotcl::RelationSlot create ${os}::Object::slot::filter -elementtype \"\"\n"
+"::xotcl::RelationSlot create ${os}::Class::slot::mixin -methodname class-mixin\n"
+"::xotcl::RelationSlot create ${os}::Class::slot::filter -elementtype \"\" \\\n"
 "-methodname filter-mixin\n"
 "::xotcl::RelationSlot create ${os}::Class::slot::object-mixin\n"
-"::xotcl::RelationSlot create ${os}::Class::slot::object-filter \\\n"
-"-elementtype \"\"}\n"
+"::xotcl::RelationSlot create ${os}::Class::slot::object-filter -elementtype \"\"}\n"
 "::xotcl::register_system_slots ::xotcl2\n"
+"proc ::xotcl::register_system_slots {} {}\n"
 "::xotcl::MetaSlot __invalidateobjectparameter\n"
-"::xotcl::MetaSlot create ::xotcl::Attribute -superclass ::xotcl::Slot\n"
+"::xotcl::MetaSlot create ::xotcl::Attribute -superclass ::xotcl::ObjectParameterSlot\n"
 "createBootstrapAttributeSlots ::xotcl::Attribute {\n"
 "{value_check once}\n"
 "initcmd\n"
 "valuecmd\n"
 "valuechangedcmd\n"
 "arg}\n"
+"::xotcl::Attribute object method createFromParameterSyntax {target value default:optional} {\n"
+"set opts [list]\n"
+"set colonPos [string first : $value]\n"
+"if {$colonPos == -1} {\n"
+"set name $value} else {\n"
+"set properties [string range $value [expr {$colonPos+1}] end]\n"
+"set name [string range $value 0 [expr {$colonPos -1}]]\n"
+"foreach property [split $properties ,] {\n"
+"if {$property eq \"required\"} {\n"
+"lappend opts -required 1} elseif {$property eq \"multivalued\"} {\n"
+"lappend opts -multivalued 1} elseif {[string match type=* $property]} {\n"
+"set type [string range $property 5 end]\n"
+"if {![string match ::* $type]} {set type ::$type}} elseif {[string match arg=* $property]} {\n"
+"set argument [string range $property 4 end]\n"
+"lappend opts -arg $argument} else {\n"
+"set type $property}}}\n"
+"if {[info exists type]} {\n"
+"lappend opts -type $type}\n"
+"if {[info exists default]} {\n"
+"lappend opts -default $default}\n"
+"::xotcl::Attribute create ${target}::slot::$name {*}$opts}\n"
 "::xotcl::Attribute method __default_from_cmd {obj cmd var sub op} {\n"
 "$obj trace remove variable $var $op [list [::xotcl::self] [::xotcl::self proc] $obj $cmd]\n"
 "::xotcl::setinstvar $obj $var [$obj eval $cmd]}\n"
@@ -375,15 +393,15 @@
 "append __initcmd [subst -nocommands {\n"
 "if {[:exists ${:name}]} {set :__oldvalue(${:name}) [set :${:name}]}\\n}]}\n"
 "return $__initcmd}\n"
-"::xotcl::Attribute method init {} {\n"
+"::xotcl::Attribute protected method init {} {\n"
 "next ;# do first ordinary slot initialization\n"
 "set __initcmd \"\"\n"
 "if {[:exists default]} {} elseif [:exists initcmd] {\n"
 "append __initcmd \":trace add variable [list ${:name}] read \\\n"
 "\\[list [::xotcl::self] __default_from_cmd \\[::xotcl::self\\] [list [set :initcmd]]\\]\\n\"} elseif [:exists valuecmd] {\n"
 "append __initcmd \":trace add variable [list ${:name}] read \\\n"
 "\\[list [::xotcl::self] __value_from_cmd \\[::xotcl::self\\] [list [set :valuecmd]]\\]\"}\n"
-"array set \"\" [::xotcl::parameterFromSlot [self] \"value\"]\n"
+"array set \"\" [:toParameterSyntax \"value\"]\n"
 "if {$(mparam) ne \"\"} {\n"
 "if {[info exists :multivalued] && ${:multivalued}} {\n"
 ":method assign [list obj var value:$(mparam),multivalued] {::xotcl::setinstvar $obj $var $value}\n"
@@ -394,83 +412,32 @@
 "\\[list [::xotcl::self] __value_changed_cmd \\[::xotcl::self\\] [list [set :valuechangedcmd]]\\]\"}\n"
 "if {$__initcmd ne \"\"} {\n"
 "set :initcmd $__initcmd}}\n"
-"::xotcl2::Class create ::xotcl::Slot::Nocheck {\n"
+"::xotcl2::Class create ::xotcl::ObjectParameterSlot::Nocheck {\n"
 ":method check_single_value args {;}\n"
 ":method check_multiple_values args {;}\n"
 ":method mk_type_checker args {return \"\"}}\n"
-"::xotcl2::Class create ::xotcl::Slot::Optimizer {\n"
+"::xotcl2::Class create ::xotcl::ObjectParameterSlot::Optimizer {\n"
 ":method method args  {::xotcl::next; :optimize}\n"
 ":method forward args {::xotcl::next; :optimize}\n"
-":method init args    {::xotcl::next; :optimize}\n"
+":protected method init args    {::xotcl::next; :optimize}\n"
 ":public method optimize {} {\n"
 "if {[set :multivalued]} return\n"
 "if {[set :defaultmethods] ne {get assign}} return\n"
-"if {[:info callable -which assign] ne \"::xotcl::Slot alias assign ::xotcl::setinstvar\"} return\n"
-"if {[:info callable -which get]    ne \"::xotcl::Slot alias get ::xotcl::setinstvar\"} return\n"
+"if {[:info callable -which assign] ne \"::xotcl::ObjectParameterSlot alias assign ::xotcl::setinstvar\"} return\n"
+"if {[:info callable -which get]    ne \"::xotcl::ObjectParameterSlot alias get ::xotcl::setinstvar\"} return\n"
 "::xotcl::setter ${:domain} {*}[expr {${:per-object} ? \"-per-object\" : \"\"}] ${:name}}}\n"
-"::xotcl::Attribute mixin add ::xotcl::Slot::Optimizer\n"
+"::xotcl::Attribute mixin add ::xotcl::ObjectParameterSlot::Optimizer\n"
 "::xotcl2::Class public method parameter arglist {\n"
 "if {![::xotcl::is [::xotcl::self]::slot object]} {\n"
 "::xotcl2::Object create [::xotcl::self]::slot}\n"
 "foreach arg $arglist {\n"
-"set l [llength $arg]\n"
-"set name [lindex $arg 0]\n"
-"set opts [list]\n"
-"set colonPos [string first : $name]\n"
-"if {$colonPos > -1} {\n"
-"set properties [string range $name [expr {$colonPos+1}] end]\n"
-"set name [string range $name 0 [expr {$colonPos -1}]]\n"
-"foreach property [split $properties ,] {\n"
-"if {$property eq \"required\"} {\n"
-"lappend opts -required 1} elseif {$property eq \"multivalued\"} {\n"
-"lappend opts -multivalued 1} elseif {[string match type=* $property]} {\n"
-"set type [string range $property 5 end]\n"
-"if {![string match ::* $type]} {set type ::$type}} elseif {[string match arg=* $property]} {\n"
-"set argument [string range $property 4 end]\n"
-"lappend opts -arg $argument} else {\n"
-"set type $property}}}\n"
-"if {[info exists type]} {\n"
-"lappend opts -type $type\n"
-"unset type}\n"
-"set cmd [list ::xotcl::Attribute create [::xotcl::self]::slot::$name {*}$opts]\n"
-"if {$l == 1} {\n"
-"eval $cmd} elseif {$l == 2} {\n"
-"lappend cmd -default [lindex $arg 1]\n"
-"eval $cmd} elseif {$l == 3 && [lindex $arg 1] eq \"-default\"} {\n"
-"lappend cmd -default [lindex $arg 2]\n"
-"eval $cmd} else {\n"
-"set paramstring [string range $arg [expr {[string length $name]+1}] end]\n"
-"if {[string match {[$\\[]*} $paramstring]} {\n"
-"lappend cmd -default $paramstring\n"
-"eval $cmd\n"
-"continue}\n"
-"set po ::xotcl2::Class::Parameter\n"
-"puts stderr \"deprecated parameter usage '$arg'; use '-slots {Attribute ...}' instead\"\n"
-"set cl [::xotcl::self]\n"
-"::xotcl::setinstvar $po name $name\n"
-"::xotcl::setinstvar $po cl [::xotcl::self]\n"
-"::eval $po configure [lrange $arg 1 end]\n"
-"if {[$po exists extra] || [$po exists setter] ||\n"
-"[$po exists getter] || [$po exists access]} {\n"
-"::xotcl::importvar $po extra setter getter access defaultParam\n"
-"if {![info exists extra]} {set extra \"\"}\n"
-"if {![info exists defaultParam]} {set defaultParam \"\"}\n"
-"if {![info exists setter]} {set setter set}\n"
-"if {![info exists getter]} {set getter set}\n"
-"if {![info exists access]} {set access ::xotcl::my}\n"
-"$cl public method $name args \"\n"
-"if {\\[llength \\$args] == 0} {\n"
-"return \\[$access $getter $extra $name\\]} else {\n"
-"return \\[eval $access $setter $extra $name \\$args $defaultParam \\]}\"\n"
-"foreach instvar {extra defaultParam setter getter access} {\n"
-"$po unset -nocomplain $instvar}} else {\n"
-".setter $name}}}\n"
+"::xotcl::Attribute createFromParameterSyntax [self] {*}$arg}\n"
 "::xotcl::setinstvar [::xotcl::self]::slot __parameter $arglist}\n"
 "proc createBootstrapAttributeSlots {} {}}\n"
 "::xotcl2::Class create ::xotcl::ScopedNew -superclass ::xotcl2::Class -parameter {\n"
 "{withclass ::xotcl2::Object}\n"
 "inobject}\n"
-"::xotcl::ScopedNew method init {} {\n"
+"::xotcl::ScopedNew protected method init {} {\n"
 ":public method new {-childof args} {\n"
 "::xotcl::importvar [::xotcl::self class] {inobject object} withclass\n"
 "if {![::xotcl::is $object object]} {\n"