[WWcvs] pg: Fixed problem with minus signs in formulas that are turned into perl

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

Log Message:
-----------
Fixed problem with minus signs in formulas that are turned into perl
mode.  Perl needs extra spaces to avoid problems with -e type operators.

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

Revision Data
-------------
Index: Default.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser/Context/Default.pm,v
retrieving revision 1.26
retrieving revision 1.27
diff -Llib/Parser/Context/Default.pm -Llib/Parser/Context/Default.pm -u -r1.26 -r1.27
--- lib/Parser/Context/Default.pm
+++ lib/Parser/Context/Default.pm
@@ -18,7 +18,7 @@
            class => 'Parser::BOP::add'},
 
    '-' => {precedence => 1, associativity => 'left', type => 'both', string => '-',
-           class => 'Parser::BOP::subtract', rightparens => 'same'},
+           perl => '- ', class => 'Parser::BOP::subtract', rightparens => 'same'},
 
    '><'=> {precedence => 2, associativity => 'left', type => 'bin',
            string => ' >< ', TeX => '\times ', perl => ' x ', fullparens => 1,
@@ -57,7 +57,7 @@
    'u+'=> {precedence => 6, associativity => 'left', type => 'unary', string => '+',
            class => 'Parser::UOP::plus', hidden => 1, allowInfinite => 1, nofractionparens => 1},
 
-   'u-'=> {precedence => 6, associativity => 'left', type => 'unary', string => '-',
+   'u-'=> {precedence => 6, associativity => 'left', type => 'unary', string => '-', perl => '- ',
            class => 'Parser::UOP::minus', hidden => 1, allowInfinite => 1, nofractionparens => 1},
 
    '^' => {precedence => 7, associativity => 'right', type => 'bin', string => '^', perl => '**',