--- loncom/homework/response.pm	2006/10/17 17:09:44	1.148
+++ loncom/homework/response.pm	2006/12/15 22:11:43	1.156
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # various response type definitons response definition
 #
-# $Id: response.pm,v 1.148 2006/10/17 17:09:44 albertel Exp $
+# $Id: response.pm,v 1.156 2006/12/15 22:11:43 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,6 +30,7 @@ package Apache::response;
 use strict;
 use Apache::lonlocal;
 use Apache::lonnet;
+use Apache::lonmaxima();
 
 BEGIN {
     &Apache::lonxml::register('Apache::response',('responseparam','parameter','dataresponse','customresponse','mathresponse'));
@@ -306,7 +307,7 @@ sub handle_previous {
 }
 
 sub view_or_modify {
-    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
     my $myself=0;
     if ( ($name eq $env{'user.name'}) && ($domain eq $env{'user.domain'}) ) {
 	$myself=1;
@@ -340,7 +341,7 @@ sub end_dataresponse {
     if ( $target eq 'web' ) {
     } elsif ($target eq 'grade' ) {
 	if ( defined $env{'form.submitted'}) {
-	    my ($symb,$courseid,$domain,$name)=&Apache::lonxml::whichuser();
+	    my ($symb,$courseid,$domain,$name)=&Apache::lonnet::whichuser();
 	    my $allowed=&Apache::lonnet::allowed('mgr',$courseid);
 	    if ($allowed) {
 		&Apache::response::setup_params('dataresponse',$safeeval);
@@ -373,7 +374,7 @@ sub start_customresponse {
   	if (  &Apache::response::show_answer() ) {
 	    my $answer = &Apache::lonxml::get_param('answerdisplay',$parstack,
 						   $safeeval);
-	    $Apache::inputtags::answertxt{$id}=$answer;
+	    $Apache::inputtags::answertxt{$id}=[$answer];
 	}
     } elsif ($target eq 'edit') {
 	$result.=&Apache::edit::tag_start($target,$token);
@@ -464,17 +465,23 @@ sub start_mathresponse {
   	if (  &Apache::response::show_answer() ) {
 	    my $answer = &Apache::lonxml::get_param('answerdisplay',$parstack,
 						   $safeeval);
-	    $Apache::inputtags::answertxt{$id}=$answer;
+	    $Apache::inputtags::answertxt{$id}=[$answer];
 	}
     } elsif ($target eq 'edit') {
 	$result.=&Apache::edit::tag_start($target,$token);
 	$result.=&Apache::edit::text_arg('String to display for answer:',
 					 'answerdisplay',$token);
+	$result.=&Apache::edit::select_arg('Algebra System:',
+					   'cas',
+					   ['maxima'],
+					   $token);
+	$result.=&Apache::edit::text_arg('Argument Array:',
+					 'args',$token);
 	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
     } elsif ($target eq 'modified') {
 	my $constructtag;
 	$constructtag=&Apache::edit::get_new_args($token,$parstack,
-						  $safeeval,'answerdisplay');
+						  $safeeval,'answerdisplay','cas','args');
 	if ($constructtag) {
 	    $result = &Apache::edit::rebuild_tag($token);
 	    $result.=&Apache::edit::handle_insert();
@@ -494,8 +501,7 @@ sub end_mathresponse {
     my $id=$Apache::inputtags::response[-1];
     if ( $target eq 'grade' && &Apache::response::submitted() ) {
 	my $response = &Apache::response::getresponse();
-	if ( $response =~ /[^\s]/ && 
-	     $Apache::response::custom_answer_type eq 'loncapa/perl') {
+	if ( $response =~ /[^\s]/ ) {
 	    if (!$Apache::lonxml::default_homework_loaded) {
 		&Apache::lonxml::default_homework_load($safeeval);
 	    }
@@ -504,10 +510,12 @@ sub end_mathresponse {
 	    $Apache::lonhomework::results{"resource.$part.$id.submission"}=
 		$response;
 	    my $error;
-	    ${$safeeval->varglob('LONCAPA::mathresponse_submission')}=
-		$response;
-	    
-	    my $award = &Apache::run::run('{ my $submission=$LONCAPA::mathresponse_submission;'.$Apache::response::custom_answer.'}',$safeeval);
+	    my $award;
+	    my $cas = &Apache::lonxml::get_param('cas',$parstack,$safeeval);
+            if ($cas eq 'maxima') {
+                my $args = [&Apache::lonxml::get_param_var('args',$parstack,$safeeval)];
+                $award=&Apache::lonmaxima::maxima_run($Apache::response::custom_answer,$response,$args);
+            }
 	    if (!&Apache::inputtags::valid_award($award)) {
 		$error = $award;
 		$award = 'ERROR';
@@ -527,6 +535,28 @@ sub end_mathresponse {
     return $result;
 }
 
+sub implicit_multiplication {
+    my ($expression)=@_;
+# Escape scientific notation, so 3e8 does not become 3*e*8
+# 3e8 -> 3&8; 3e-8 -> 3&-8; 3E+8 -> e&+8
+    $expression=~s/(\d+)e([\+\-]*\d+)/$1\&\($2\)/gsi;
+# 3x10^8 -> 3&8; 3*10^-8 -> 3&-8
+    $expression=~s/(\d+)(?:x|\*)10(?:\^|\*\*)([\+\-]*\d+)/$1\&\($2\)/gsi;
+# Fill in multiplication signs
+# a b -> a*b;3 b -> 3*b;3 4 -> 3*4
+    $expression=~s/(\w)\s+(\w)/$1\*$2/gs;
+# )( -> )*(; ) ( -> )*(
+    $expression=~s/\)\s*\(/\)\*\(/gs;
+# 3a -> 3*a; 3( -> 3*(; 3 ( -> 3*(; 3A -> 3*A
+    $expression=~s/(\d)\s*([a-zA-Z\(])/$1\*$2/gs;
+# a ( -> a*(
+    $expression=~s/(\w)\s+\(/$1\*\(/gs;
+# )a -> )*a; )3 -> )*3; ) 3 -> )*3
+    $expression=~s/\)\s*(\w)/\)\*$1/gs;
+# 3&8 -> 3e8; 3&-4 -> 3e-4
+    $expression=~s/(\d+)\&\(([\+\-]*\d+)\)/$1e$2/gs;
+    return $expression;
+}
 
 sub start_answer {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
@@ -776,7 +806,7 @@ sub answer_footer {
 
 sub showallfoils {
     if (defined($env{'form.showallfoils'})) {
-	my ($symb)=&Apache::lonxml::whichuser();
+	my ($symb)=&Apache::lonnet::whichuser();
 	if (($env{'request.state'} eq 'construct') || 
 	    ($env{'user.adv'} && $symb eq '')      ||
             ($Apache::lonhomework::viewgrades) ) {
@@ -998,7 +1028,7 @@ sub submitted {
 }
 
 sub add_to_gradingqueue {
-    my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    my ($symb,$courseid,$domain,$name) = &Apache::lonnet::whichuser();
     if (   $courseid eq ''
 	|| $symb eq ''
 	|| $env{'request.state'} eq 'construct'