sub is_tf { my ($in,$out,$label) = @_; is( rec( $in ) => $out => "$label: \t'$in'\t->\t'$out'" ); } sub no_tf { my ($in,$label) = @_; is_tf($in,$in,$label); } no_tf( '**' => "no letter" ); is_tf( '*A*' => 'A' => "one letter"); is_tf( '*A B*' ,'A B' , "multi word"); no_tf( '* A*' , "before non-whitespace"); no_tf( '*A *' , "after non-whitespace"); no_tf( "*A\nB*" , "line break"); is_tf( '*A *B*' ,'A *B' , "after non-whitespace prolonged"); is_tf( '/**/' ,'**' , "nested no letter");