Index: lib/perl/cqpwebCEQL.pm
===================================================================
--- lib/perl/cqpwebCEQL.pm	(revision 338)
+++ lib/perl/cqpwebCEQL.pm	(working copy)
@@ -94,9 +94,13 @@
 
 
 # override lemma_pattern rule to provide support for {book/V} notation
+## *** local patch: modify lemma_pattern to allow negation ***
 sub lemma_pattern {
   my ($self, $lemma) = @_;
   
+  # condition is negated if lemma begins with ! (but not if ! is the only character)
+  my $neg = ($lemma =~ s/^!(?=.)//) ? "!" : ""; # $neg can be interpolated in to the generated CQP queries
+  
   # split lemma into headword pattern and optional simple POS constraint
   my ($hw, $tag, $extra) = split /(?<!\\)\//, $lemma;
   die "Only a single ''/'' separator is allowed between the first and second search terms in a {.../...} search.\n"
@@ -124,24 +128,60 @@
     my $attr = $self->GetParam("combo_attribute");
     if (defined $attr) {
       $regexp =~ s/^"//; $regexp =~ s/"$//; # remove double quotes around regexp so it can be combined with POS constraint
-      return "$attr=\"($regexp)_${tag_regexp}\"";
+      return "$attr${neg}=\"($regexp)_${tag_regexp}\"";
     }
     else {
       my $first_attr = $self->GetParam("lemma_attribute")
         or die "Searches of the form {.../...} are not available.\n";
       my $second_attr = $self->GetParam("simple_pos_attribute")
         or die "Searches of the form {.../...} are not available.\n";
-      return "($first_attr=$regexp & $second_attr=\"${tag_regexp}\")";
+      return "${neg}($first_attr=$regexp & $second_attr=\"${tag_regexp}\")";
     }
   }
   else {
     # no simple POS specified => match the normal lemma attribute.
     my $attr = $self->GetParam("lemma_attribute")
       or die "Searches of the form {...} are not available.\n";
-    return "$attr=$regexp";
+    return "$attr${neg}=$regexp";
   }
 }
 
+
+## *** local patch: also override wordform_pattern, pos_tag and simple_pos to support negated constraints ***
+sub wordform_pattern {
+  my ($self, $wf) = @_;
+  my $neg = ($wf =~ s/^!(?=.)//) ? "!" : ""; # $neg can be interpolated in to the generated CQP queries
+  my $regexp = $self->Call("wildcard_pattern", $wf);
+  return "word${neg}=$regexp";
+}
+
+sub pos_tag {
+  my ($self, $tag) = @_;
+  my $neg = ($tag =~ s/^!(?=.)//) ? "!" : ""; # $neg can be interpolated in to the generated CQP queries
+  my $attr = $self->GetParam("pos_attribute")
+    or die "no attribute defined for part-of-speech tags (internal error)\n";
+  my $regexp = $self->Call("wildcard_pattern", $tag);
+  return "$attr${neg}=$regexp";
+}
+
+sub simple_pos {
+  my ($self, $tag) = @_;
+  my $neg = ($tag =~ s/^!(?=.)//) ? "!" : ""; # $neg can be interpolated in to the generated CQP queries
+  my $attr = $self->GetParam("simple_pos_attribute") || $self->GetParam("pos_attribute")
+    or die "no attribute defined for part-of-speech tags (internal error)\n";
+  my $lookup = $self->GetParam("simple_pos");
+  die "no simple part-of-speech tags are available for this corpus\n"
+    unless ref($lookup) eq "HASH";
+  my $regexp = $lookup->{$tag};
+  if (not defined $regexp) {
+    my @valid_tags = sort keys %$lookup;
+    die "'' $tag '' is not a valid simple part-of-speech tag (available tags: '' @valid_tags '')\n";
+  }
+  return "$attr${neg}=\"$regexp\"";
+}
+
+
+
 =head1 COPYRIGHT
 
 Copyright (C) 1999-2008 Stefan Evert [http::/purl.org/stefan.evert]