[WWcvs] pg: Make fractions stringify with parentheses properly

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

Log Message:
-----------
Make fractions stringify with parentheses properly

Modified Files:
--------------
    pg/macros:
        contextFraction.pl

Revision Data
-------------
Index: contextFraction.pl
===================================================================
RCS file: /webwork/cvs/system/pg/macros/contextFraction.pl,v
retrieving revision 1.6
retrieving revision 1.7
diff -Lmacros/contextFraction.pl -Lmacros/contextFraction.pl -u -r1.6 -r1.7
--- macros/contextFraction.pl
+++ macros/contextFraction.pl
@@ -771,6 +771,12 @@
   return $n;
 }
 
+sub pdot {
+  my $self = shift; my $n = $self->string;
+  $n = '('.$n.')' if $n =~ m![^0-9]!;  #  add parens if not just a number
+  return $n;
+}
+
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