[WWcvs] pg: Fixed a problem with redefine when used with classes that store

[dpvc v. a. <we...@ma...>]

Log Message:
-----------
Fixed a problem with redefine when used with classes that store their
data in a on-standard form (i.e., by overridding the create()
method).  Now they can define uncreate() to get the original data back
for use with redefine().

Modified Files:
--------------
    pg/lib/Parser/Context:
        Constants.pm
        Variables.pm
    pg/lib/Value/Context:
        Data.pm

Revision Data
-------------
Index: Constants.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser/Context/Constants.pm,v
retrieving revision 1.3
retrieving revision 1.4
diff -Llib/Parser/Context/Constants.pm -Llib/Parser/Context/Constants.pm -u -r1.3 -r1.4
--- lib/Parser/Context/Constants.pm
+++ lib/Parser/Context/Constants.pm
@@ -16,12 +16,13 @@
 }
 
 #
-#  Create data for constants
+#  Create/Uncreate data for constants
 #
 sub create {
   my $self = shift; my $value = shift;
   return {value => $value, keepName => 1};
 }
+sub uncreate {shift; (shift)->{value}}
 
 #
 #  Return a constant's value
Index: Variables.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser/Context/Variables.pm,v
retrieving revision 1.8
retrieving revision 1.9
diff -Llib/Parser/Context/Variables.pm -Llib/Parser/Context/Variables.pm -u -r1.8 -r1.9
--- lib/Parser/Context/Variables.pm
+++ lib/Parser/Context/Variables.pm
@@ -61,6 +61,7 @@
   }
   return {type => $value, @extra};
 }
+sub uncreate {shift; (shift)->{type}};
 
 #
 #  Return a variable's type
Index: Data.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Value/Context/Data.pm,v
retrieving revision 1.7
retrieving revision 1.8
diff -Llib/Value/Context/Data.pm -Llib/Value/Context/Data.pm -u -r1.7 -r1.8
--- lib/Value/Context/Data.pm
+++ lib/Value/Context/Data.pm
@@ -26,6 +26,7 @@
 #
 sub init {}
 sub create {shift; shift}
+sub uncreate {shift; shift}
 
 #
 #  Sort names so that they can be joined for regexp matching
@@ -158,7 +159,7 @@
     Value::Error("No definition for %s '%s' in the given context",$self->{name},$y)
       unless $from->{$self->{dataName}}{$y};
     push(@remove,$x) if $self->get($x);
-    push(@data,$x => $from->{$self->{dataName}}{$y});
+    push(@data,$x => $self->uncreate($from->{$self->{dataName}}{$y}));
   }
   $self->remove(@remove);
   $self->add(@data);