[WWcvs] pg: Allow the perlFunction method to produce functions that return formulas when not all the variables are used as arguments.

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

Log Message:
-----------
Allow the perlFunction method to produce functions that return
formulas when not all the variables are used as arguments.

For example:

    Formula("x+y")->perlFunction('f',['x']);
    $f = f(2);

would produce the equivalent of

    $f = Formula("2+y");

Using the substitute method is more efficient, but this now does the
right thing rather than generate error messages.

Modified Files:
--------------
    pg/lib:
        Parser.pm

Revision Data
-------------
Index: Parser.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser.pm,v
retrieving revision 1.50
retrieving revision 1.51
diff -Llib/Parser.pm -Llib/Parser.pm -u -r1.50 -r1.51
--- lib/Parser.pm
+++ lib/Parser.pm
@@ -706,11 +706,15 @@
 sub perlFunction {
   my $self = shift; my $name = shift || ''; my $vars = shift;
   $vars = [sort(keys %{$self->{variables}})] unless $vars;
-  my $n = scalar(@{$vars}); my $vnames = '';
+  $vars = [$vars] unless ref($vars) eq 'ARRAY';
+  my $n = scalar(@{$vars}); my $vnames = ''; my %isArg;
   if ($n > 0) {
-    my @v = (); foreach my $x (@{$vars}) {CORE::push(@v,"\$".$x)}
+    my @v = ();
+    foreach my $x (@{$vars}) {CORE::push(@v,"\$".$x); $isArg{$x} = 1}
     $vnames = "my (".join(',',@v).") = \@_;";
   }
+  foreach my $x (keys %{$self->{variables}})
+    {$vnames .= "\n      my \$$x = main::Formula('$x');" unless $isArg{$x}}
   my $context = $self->context;
   my $fn = eval
    "package main;