Index: tests/parameters.test
===================================================================
diff -u -r3a246dd237252e81aa7f4a37cba2affb0b9ecf00 -r58c1880b874484f218afa0275b0998e25d4282f0
--- tests/parameters.test	(.../parameters.test)	(revision 3a246dd237252e81aa7f4a37cba2affb0b9ecf00)
+++ tests/parameters.test	(.../parameters.test)	(revision 58c1880b874484f218afa0275b0998e25d4282f0)
@@ -249,7 +249,7 @@
   C create c1
  
   ? {C eval :objectparameter} \
-      "-a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
+      "-a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
 
   ? {c1 eval :objectparameter} \
       "::c1: unable to dispatch method 'objectparameter'"
@@ -276,7 +276,7 @@
       "::D::slot::d ::C::slot::a ::C::slot::b ::C::slot::c"
   
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
 }
 
 #######################################################
@@ -293,29 +293,29 @@
   D mixin M
 
   ? {D eval :objectparameter} \
-      "-b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
+      "-b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
     "mixin added"
 
   M mixin M2
 
   ? {D eval :objectparameter} \
-      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
+      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
     "transitive mixin added"
   D mixin ""
   #we should have again the old interface
 
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
 
   C mixin M
   ? {D eval :objectparameter} \
-      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
+      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" \
     "mixin added"
   C mixin ""
   #we should have again the old interface
   
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" 
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional" 
 }
 
 #######################################################
@@ -688,10 +688,33 @@
   Class create D -superclass C -attributes d
 
   Class create M
+  Class create M2
   D create d1 -d 1
   C create c1 -mixin M
+  C create c2 -mixin {{M -guard true}}
+  C create c3 -mixin {M ::M2}
+  C create c4 -mixin {{M -guard 1} M2}
+  C create c5 -mixin {M {M2 -guard 2}}
   Object create o
-  
+
+  ? {c1 info mixin classes} ::M
+  ? {c1 info mixin guard ::M} ""
+
+  ? {c2 info mixin classes} ::M
+  ? {c2 info mixin guard ::M} "true"
+
+  ? {c3 info mixin classes} {::M ::M2}
+  ? {c3 info mixin guard M} ""
+  ? {c3 info mixin guard M2} ""
+
+  ? {c4 info mixin classes} {::M ::M2}
+  ? {c4 info mixin guard M} "1"
+  ? {c4 info mixin guard M2} ""
+
+  ? {c5 info mixin classes} {::M ::M2}
+  ? {c5 info mixin guard M} ""
+  ? {c5 info mixin guard M2} "2"
+
   D public method foo-base     {x:baseclass} {return $x}
   D public method foo-class    {x:class} {return $x}
   D public method foo-object   {x:object} {return $x}
@@ -1596,7 +1619,7 @@
 
   ? {C info slots -closure} "::C::slot::a1 ::nx::Object::slot::volatile ::nx::Object::slot::noinit ::nx::Object::slot::mixin ::nx::Object::slot::__initcmd ::nx::Object::slot::class ::nx::Object::slot::filter"
 
-  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
+  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
 
   #
   # invalidate object parameter and expect that the per-class mixin
@@ -1610,7 +1633,7 @@
 
   ? {C info slots -closure} "::C::slot::a1 ::nx::Object::slot::volatile ::nx::Object::slot::noinit ::nx::Object::slot::mixin ::nx::Object::slot::__initcmd ::nx::Object::slot::class ::nx::Object::slot::filter"
 
-  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:class,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
+  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinspec,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:alias,1..n __initcmd:initcmd,optional"
 
   # should not require b1
   ? {C create c2} ::c2