--- loncom/xml/run.pm	2001/11/29 19:03:58	1.21
+++ loncom/xml/run.pm	2002/04/10 14:46:30	1.25
@@ -1,6 +1,6 @@
 package Apache::run;
 #
-# $Id: run.pm,v 1.21 2001/11/29 19:03:58 www Exp $
+# $Id: run.pm,v 1.25 2002/04/10 14:46:30 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,40 +25,19 @@ package Apache::run;
 # http://www.lon-capa.org/
 #
 
-sub evaluateold {
-  my ($expression,$safeeval,$decls) = @_;
-# print "inside2 evaluate $decls with $expression<br />\n";
-# gerd's old method interpolates unset vars
-# $safeeval->reval('return qq('.$expression.');');
-  unless (defined $expression) { return ''; }
-  my $result = '';
-  $@='';
-  $safeeval->reval('$_=q|'.$expression.'|;');
-  if ($@ eq '') {
-    $safeeval->reval('{'.$decls.'$_=~s/(\$[A-Za-z]\w*)/(defined(eval($1))?eval($1):$1)/ge;}');
-    if ($@ eq '') {
-      $result = $safeeval->reval('return $_;');
-    } else {
-      &Apache::lonxml::error("substitution on:$expression:with:$decls:caused");
-    }
-  } else {
-    &Apache::lonxml::error("defining:$expression:caused");
-  }
-  if ($@ ne '') {&Apache::lonxml::error($@);}
-  return $result
-}
-
 $Apache::run::EVALUATE_STRING=<<'ENDEVALUATE';  
-  my %oldexpressions=();
-  while (!$oldexpressions{$_}) {
-    $oldexpressions{$_}=1;
+  my %_LONCAPA_INTERNAL_oldexpressions=();
+  my $i=0;
+  while (!$_LONCAPA_INTERNAL_oldexpressions{$_}) {
+    $_LONCAPA_INTERNAL_oldexpressions{$_}=1;
     $_ =~s/((?:\$|\&)(?:[\#|\$]*[A-Za-z][\w]*|\{[A-Za-z][\w]*\}))([\[\{][^\$\&\]\}]+[\]\}])*?(\([^\$\&\)]+\))*?(?=[^\[\{\(]|$)/eval(defined(eval($1.$2))?eval('$1.$2.$3'):'$1.$2.$3')/seg;
+    if ($i++ > 10 ) { last; }
   }
 ENDEVALUATE
 
 sub evaluate {
   my ($expression,$safeeval,$decls) = @_;
-  unless (defined $expression) { return ''; }
+  unless (defined($expression)) { return ''; }
   if (!$Apache::lonxml::evaluate) { return $expression; }
   my $result = '';
   $@='';
@@ -80,8 +59,8 @@ sub run {
   $@='';
   my (@result)=$safeeval->reval($code);
   if ($@ ne '' && !$hideerrors) {
-    &Apache::lonxml::error(":$code:caused");
-    &Apache::lonxml::error($@);
+    # Put in newline to make display of code easier to read.
+    &Apache::lonxml::error(":$@: occured while running :\n$code");
   }
   if ( $#result < '1') {
     return $result[0];
@@ -99,11 +78,11 @@ sub dump {
       if ($safeeval->reval('defined($'.$symname.')')) {
 	$dump.='$'.$symname.'='.$safeeval->reval('$'.$symname)."\n";
       }	
-      if ($safeeval->reval('defined @'.$symname)) {
+      if ($safeeval->reval('defined(@'.$symname.')')) {
 	$dump.='@'.$symname.'=('.
 	  $safeeval->reval('join(",",@'.$symname.')').")\n";
       }
-      if ($safeeval->reval('defined %'.$symname)) {
+      if ($safeeval->reval('defined(%'.$symname.')')) {
 	$dump.='%'.$symname.'=(';
 	$dump.=$safeeval->reval('join(",",map { $_."=>".$'.
 				$symname.'{$_} } sort keys %'.