Remove non-necessary Span postings and queries
diff --git a/lib/Krawfish/Index/Stream/Span.pm b/lib/Krawfish/Index/Stream/Span.pm
index 5974a6e..05de891 100644
--- a/lib/Krawfish/Index/Stream/Span.pm
+++ b/lib/Krawfish/Index/Stream/Span.pm
@@ -1,6 +1,6 @@
 package Krawfish::Index::Stream::Span;
 use parent 'Krawfish::Index::Stream';
-use Krawfish::Posting::Span;
+use Krawfish::Posting::Token;
 use strict;
 use warnings;
 
@@ -85,7 +85,7 @@
 
 sub posting {
   shift;
-  return Krawfish::Posting::Span->new(@_);
+  return Krawfish::Posting::Token->new(@_);
 };
 
 
diff --git a/lib/Krawfish/Koral/Query/Span.pm b/lib/Krawfish/Koral/Query/Span.pm
index 3ad2e74..87374d3 100644
--- a/lib/Krawfish/Koral/Query/Span.pm
+++ b/lib/Krawfish/Koral/Query/Span.pm
@@ -1,15 +1,12 @@
 package Krawfish::Koral::Query::Span;
 use parent 'Krawfish::Koral::Query';
-use Krawfish::Koral::Query::SpanID;
+use Krawfish::Koral::Query::TermID;
 use Krawfish::Koral::Query::Term;
 use Krawfish::Log;
-# use Krawfish::Query::Span;
 use Scalar::Util qw/blessed/;
 use strict;
 use warnings;
 
-# TODO: Rename 'wrap' to 'operand'
-
 use constant DEBUG => 0;
 
 sub new {
@@ -77,7 +74,7 @@
 
     return $self->builder->nothing unless defined $term_id;
 
-    return Krawfish::Koral::Query::SpanID->new($term_id);
+    return Krawfish::Koral::Query::TermID->new($term_id);
   };
 
   warn 'Regexes are currently not supported';
diff --git a/lib/Krawfish/Koral/Query/SpanID.pm b/lib/Krawfish/Koral/Query/SpanID.pm
deleted file mode 100644
index cc8859f..0000000
--- a/lib/Krawfish/Koral/Query/SpanID.pm
+++ /dev/null
@@ -1,33 +0,0 @@
-package Krawfish::Koral::Query::SpanID;
-use parent 'Krawfish::Koral::Query::Span';
-use Krawfish::Query::SpanID;
-use warnings;
-use strict;
-
-# TODO:
-#   This may be irrelevant if the postings in
-#   Krawfish::Query::Span/SpanID could be
-#   more general.
-
-sub new {
-  my ($class, $term_id) = @_;
-  bless {
-    term_id => $term_id
-  }, $class;
-};
-
-sub type {
-  'spanid'
-};
-
-
-sub optimize {
-  my ($self, $segment) = @_;
-  return Krawfish::Query::SpanID->new($segment, $self->{term_id});
-};
-
-sub to_string {
-  '#' . $_[0]->{term_id};
-};
-
-1;
diff --git a/lib/Krawfish/Posting/Span.pm b/lib/Krawfish/Posting/Span.pm
deleted file mode 100644
index ac045d6..0000000
--- a/lib/Krawfish/Posting/Span.pm
+++ /dev/null
@@ -1,34 +0,0 @@
-package Krawfish::Posting::Span;
-use parent 'Krawfish::Posting';
-use strict;
-use warnings;
-
-sub new {
-  my $class = shift;
-  bless [@_], $class;
-}
-
-# Current document
-sub doc_id {
-  return $_[0]->[0];
-};
-
-
-# Start of span
-sub start {
-  return $_[0]->[1];
-};
-
-
-# End of span
-sub end {
-  return $_[0]->[2];
-};
-
-# Payloads
-sub payload {
-  return $_[0]->[3] //= Krawfish::Posting::Payload->new;
-};
-
-
-1;
diff --git a/lib/Krawfish/Query/Filter.pm b/lib/Krawfish/Query/Filter.pm
index 27a04c4..075c3e5 100644
--- a/lib/Krawfish/Query/Filter.pm
+++ b/lib/Krawfish/Query/Filter.pm
@@ -37,7 +37,7 @@
 
   my $span = $self->{span}->current;
 
-  # No valid span
+  # Invalidate current if no current span exists
   unless ($span) {
     $self->{doc_id} = undef;
     return;
@@ -45,6 +45,7 @@
 
   my $doc = $self->{docs}->current;
 
+  # Invalidate current if no current doc exists
   unless ($doc) {
     $self->{doc_id} = undef;
     return;
diff --git a/lib/Krawfish/Query/SpanID.pm b/lib/Krawfish/Query/SpanID.pm
deleted file mode 100644
index 450d56f..0000000
--- a/lib/Krawfish/Query/SpanID.pm
+++ /dev/null
@@ -1,25 +0,0 @@
-package Krawfish::Query::SpanID;
-use parent 'Krawfish::Query::TermID';
-use Krawfish::Index::PostingsList;
-use Krawfish::Posting::Span;
-use strict;
-use warnings;
-
-# ---------------------------
-# TODO:
-#   May be useless, if Postings can be adjusted.
-# ---------------------------
-
-# TODO: Probably rename to posting - and return a posting
-# that augments the given payload
-sub current {
-  my $postings = $_[0]->{postings};
-  return if $postings->pos == -1;
-  return unless $postings->current;
-
-  Krawfish::Posting::Span->new(
-    @{$postings->current}
-  );
-};
-
-1;