[WWcvs] pg: Updates to make mode=>'frac' properly emulate the original num_cmp

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

Log Message:
-----------
Updates to make mode=>'frac' properly emulate the original num_cmp
behavior (it now allows decimals and fractions instead of requiring a
fraction).  There is also a new LimitedNumeric-StrictFraction context
(not currently used) that disallows decimals and requires fractions.

Modified Files:
--------------
    pg/lib/Parser:
        Number.pm
    pg/lib/Parser/Legacy:
        LimitedNumeric.pm

Revision Data
-------------
Index: Number.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser/Number.pm,v
retrieving revision 1.10
retrieving revision 1.11
diff -Llib/Parser/Number.pm -Llib/Parser/Number.pm -u -r1.10 -r1.11
--- lib/Parser/Number.pm
+++ lib/Parser/Number.pm
@@ -15,9 +15,10 @@
   return $equation->{context}{parser}{Complex}->new($equation,$value,$ref)
     if (ref($value) eq 'ARRAY');
   $value = $value->value while Value::isReal($value);
-  $value = $value + 0; # format the value as a number, just in case
   $num = bless {
-    value => $value, type => $Value::Type{number}, isConstant => 1,
+    value => $value + 0, # format the value as a number, just in case
+    value_string => $value, # for decimal checking, etc.
+    type => $Value::Type{number}, isConstant => 1,
     ref => $ref, equation => $equation,
   }, $class;
   my $x = Value::Real->make($value);
@@ -79,7 +80,7 @@
 sub _NoDecimals {
   my $self = shift;
   $self->Error("You are not allowed to type decimal numbers in this problem")
-    unless $self->{value} =~ m/^[-+]?[0-9]+$/;
+    unless $self->{value_string} =~ m/^[-+]?[0-9]+$/;
 }
 
 
Index: LimitedNumeric.pm
===================================================================
RCS file: /webwork/cvs/system/pg/lib/Parser/Legacy/LimitedNumeric.pm,v
retrieving revision 1.2
retrieving revision 1.3
diff -Llib/Parser/Legacy/LimitedNumeric.pm -Llib/Parser/Legacy/LimitedNumeric.pm -u -r1.2 -r1.3
--- lib/Parser/Legacy/LimitedNumeric.pm
+++ lib/Parser/Legacy/LimitedNumeric.pm
@@ -10,6 +10,12 @@
 #      Context("LimiteNumeric");
 #      Context("LimitedNumeric-Fraction");
 #
+#  There is also a third version, which is a strict fraction
+#  mode (not in the original num_cmp) where ONLY fractions
+#  can be entered (not decimals).
+#
+#      Context("LimitedNumeric-StrictFraction");
+#
 
 
 #
@@ -23,7 +29,7 @@
   $self->SUPER::_check;
   my $uop = $self->{def}{string} || $self->{uop};
   $self->Error("You can only use '%s' with (non-negative) numbers",$uop)
-    unless $self->{op}->class =~ /Number|DIVIDE/;
+    unless $self->{op}->class =~ /Number|INTEGER|DIVIDE/;
 }
 
 sub class {'MINUS'};
@@ -40,13 +46,25 @@
   my $self = shift;
   $self->SUPER::_check;
   my $bop = $self->{def}{string} || $self->{bop};
-  $self->Error("You can only use '%s' between (non-negative) numbers",$bop)
-    unless $self->{lop}->class =~ /Number|MINUS/ &&
-           $self->{rop}->class eq 'Number';
+  $self->Error("You can only use '%s' between (non-negative) integers",$bop)
+    unless $self->{lop}->class =~ /INTEGER|MINUS/ &&
+           $self->{rop}->class eq 'INTEGER';
 }
 
 sub class {'DIVIDE'};
 
+#
+#  Distinguish integers from decimals
+#
+package Parser::Legacy::LimitedNumeric::Number;
+our @ISA = qw(Parser::Number);
+
+sub class {
+  my $self = shift;
+  return "INTEGER" if $self->{value_string} =~ m/^[-+]?[0-9]+$/;
+  return "Number";
+}
+
 
 package Parser::Legacy::LimitedNumeric;
 
@@ -66,7 +84,7 @@
 
 #
 #  For the Fraction versions, allow the modified division, and
-#  make sure numbers are just integers
+#  make sure numbers used in fractions are just integers
 #
 $context = $Parser::Context::Default::context{Numeric}->copy;
 $Parser::Context::Default::context{'LimitedNumeric-Fraction'} = $context;
@@ -82,6 +100,13 @@
 );
 $context->parens->undefine('|','{','[');
 $context->functions->disable('All');
+$context->{parser}{Number} = "Parser::Legacy::LimitedNumeric::Number";
+
+#
+#  For strict fractions, don't allow decimal numbers
+#
+$context = $context->copy;
+$Parser::Context::Default::context{'LimitedNumeric-StrictFraction'} = $context;
 Parser::Number::NoDecimals($context);
 
 1;