do proper quoting of unusual entity names in the dot

diff --git a/lib/Text/Tradition/Stemma.pm b/lib/Text/Tradition/Stemma.pm
index 16dad09..61ecb52 100644 (file)
--- a/lib/Text/Tradition/Stemma.pm
+++ b/lib/Text/Tradition/Stemma.pm
@@ -192,12 +192,13 @@ sub as_dot {
                push( @dotlines, _make_dotline( $n, 'label' => $ltext ) );
         } else {
                # Use the default display settings.
+               $n = _dotquote( $n );
             push( @dotlines, "  $n;" );
         }
     }
     # Add each of our edges.
     foreach my $e ( $self->graph->edges ) {
-       my( $from, $to ) = @$e;
+       my( $from, $to ) = map { _dotquote( $_ ) } @$e;
        push( @dotlines, "  $from -> $to;" );
     }
     push( @dotlines, '}' );
@@ -233,7 +234,7 @@ sub editable {
                push( @dotlines, _make_dotline( $n, 'class' => 'extant' ) );
        }
        foreach my $e ( sort _by_vertex $self->graph->edges ) {
-               my( $from, $to ) = @$e;
+               my( $from, $to ) = map { _dotquote( $_ ) } @$e;
                push( @dotlines, "  $from -> $to;" );
        }
     push( @dotlines, '}' );
@@ -244,13 +245,20 @@ sub _make_dotline {
        my( $obj, %attr ) = @_;
        my @pairs;
        foreach my $k ( keys %attr ) {
-               my $v = $attr{$k};
-               $v =~ s/\"/\\\"/g;
-               push( @pairs, "$k=\"$v\"" );
+               my $v = _dotquote( $attr{$k} );
+               push( @pairs, "$k=$v" );
        }
-       return sprintf( "  %s [ %s ];", $obj, join( ', ', @pairs ) );
+       return sprintf( "  %s [ %s ];", _dotquote( $obj ), join( ', ', @pairs ) );
 }
        
+sub _dotquote {
+       my( $str ) = @_;
+       return $str if $str =~ /^[A-Za-z0-9]+$/;
+       $str =~ s/\"/\\\"/g;
+       $str = '"' . $str . '"';
+       return $str;
+}
+
 sub _by_vertex {
        return $a->[0].$a->[1] cmp $b->[0].$b->[1];
 }