---+ Package =TWiki::LineIterator=

 Iterator over the lines in a file

 %TOC%

 ---++ new( $file )

 Create a new iterator over the given file. if the file cannot be opened, then

 there will be no elements in the iterator.

 ---++ hasNext() -> $boolean

 Returns false when the iterator is exhausted.

 <verbatim>

 my $it = new TWiki::ListIterator(\@list);

 while ($it->hasNext()) {

    ...

 </verbatim>

 ---++ next() -> $data

 Return the next line in the file.

 The iterator object can be customised to pre- and post-process entries from

 the list before returning them. This is done by setting two fields in the

 iterator object:

    * ={filter}= can be defined to be a sub that filters each entry. The entry

      will be ignored (next() will not return it) if the filter returns false.

    * ={process}= can be defined to be a sub to process each entry before it

      is returned by next. The value returned from next is the value returned

      by the process function.

 For example,

 <verbatim>

 my $it = new TWiki::LineIterator("/etc/passwd");

 $it->{filter} = sub { $_[0] =~ /^.*?:/; return $1; };

 $it->{process} = sub { return "User $_[0]"; };

 while ($it->hasNext()) {

     my $x = $it->next();

     print "$x\n";

 }

 </verbatim>