move collector construction outside filter subs

[catagits/HTML-Zoom.git] / lib / HTML / Zoom / FilterBuilder.pm

diff --git a/lib/HTML/Zoom/FilterBuilder.pm b/lib/HTML/Zoom/FilterBuilder.pm
index 71b2d5f..19cc818 100644 (file)
--- a/lib/HTML/Zoom/FilterBuilder.pm
+++ b/lib/HTML/Zoom/FilterBuilder.pm
@@ -37,7 +37,7 @@ sub set_attribute {
   my ($self, $args) = @_;
   my ($name, $value) = @{$args}{qw(name value)};
   sub {
-    my $a = (my $evt = shift)->{attrs};
+    my $a = (my $evt = $_[0])->{attrs};
     my $e = exists $a->{$name};
     +{ %$evt, raw => undef, raw_attrs => undef,
        attrs => { %$a, $name => $value },
@@ -52,7 +52,7 @@ sub add_attribute {
   my ($self, $args) = @_;
   my ($name, $value) = @{$args}{qw(name value)};
   sub {
-    my $a = (my $evt = shift)->{attrs};
+    my $a = (my $evt = $_[0])->{attrs};
     my $e = exists $a->{$name};
     +{ %$evt, raw => undef, raw_attrs => undef,
        attrs => {
@@ -70,7 +70,7 @@ sub remove_attribute {
   my ($self, $args) = @_;
   my $name = $args->{name};
   sub {
-    my $a = (my $evt = shift)->{attrs};
+    my $a = (my $evt = $_[0])->{attrs};
     return $evt unless exists $a->{$name};
     $a = { %$a }; delete $a->{$name};
     +{ %$evt, raw => undef, raw_attrs => undef,
@@ -80,28 +80,69 @@ sub remove_attribute {
   };
 }
 
+sub collect {
+  my ($self, $options) = @_;
+  my ($into, $passthrough, $inside) = @{$options}{qw(into passthrough inside)};
+  sub {
+    my ($evt, $stream) = @_;
+    # We wipe the contents of @$into here so that other actions depending
+    # on this (such as a repeater) can be invoked multiple times easily.
+    # I -suspect- it's better for that state reset to be managed here; if it
+    # ever becomes painful the decision should be revisited
+    if ($into) {
+      @$into = $inside ? () : ($evt);
+    }
+    if ($evt->{is_in_place_close}) {
+      return $evt if $passthrough || $inside;
+      return;
+    }
+    my $name = $evt->{name};
+    my $depth = 1;
+    my $_next = $inside ? 'peek' : 'next';
+    my $collector = $self->_stream_from_code(sub {
+      return unless $stream;
+      while (my ($evt) = $stream->$_next) {
+        $depth++ if ($evt->{type} eq 'OPEN');
+        $depth-- if ($evt->{type} eq 'CLOSE');
+        unless ($depth) {
+          undef $stream;
+          return if $inside;
+          push(@$into, $evt) if $into;
+          return $evt if $passthrough;
+          return;
+        }
+        push(@$into, $evt) if $into;
+        $stream->next if $inside;
+        return $evt if $passthrough;
+      }
+      die "Never saw closing </${name}> before end of source";
+    });
+    return ($passthrough||$inside) ? [ $evt, $collector ] : $collector;
+  };
+}
+
 sub add_before {
   my ($self, $events) = @_;
-  sub { return $self->_stream_from_array(@$events, shift) };
+  sub { return $self->_stream_from_array(@$events, $_[0]) };
 }
 
 sub add_after {
   my ($self, $events) = @_;
+  my $coll_proto = $self->collect({ passthrough => 1 });
   sub {
-    my ($evt, $stream) = @_;
+    my ($evt) = @_;
     my $emit = $self->_stream_from_array(@$events);
-    if ($evt->{is_in_place_close}) {
-      return [ $evt, $emit ];
-    }
-    my ($filtered_evt, $coll) = @{$self->collect(undef, 1)->(@_)};
-    return [ $filtered_evt, $self->_stream_concat($coll, $emit) ];
+    my $coll = &$coll_proto;
+    return ref($coll) eq 'HASH' # single event, no collect
+      ? [ $coll, $emit ]
+      : [ $coll->[0], $self->_stream_concat($coll->[1], $emit) ];
   };
-}  
+}
 
 sub prepend_inside {
   my ($self, $events) = @_;
   sub {
-    my $evt = shift;
+    my ($evt) = @_;
     if ($evt->{is_in_place_close}) {
       $evt = { %$evt }; delete @{$evt}{qw(raw is_in_place_close)};
       return [ $evt, $self->_stream_from_array(
@@ -112,45 +153,44 @@ sub prepend_inside {
   };
 }
 
-sub replace {
+sub append_inside {
   my ($self, $events) = @_;
+  my $coll_proto = $self->collect({ passthrough => 1, inside => 1 });
   sub {
-    my ($evt, $stream) = @_;
-    my $emit = $self->_stream_from_array(@$events);
+    my ($evt) = @_;
     if ($evt->{is_in_place_close}) {
-      return $emit
+      $evt = { %$evt }; delete @{$evt}{qw(raw is_in_place_close)};
+      return [ $evt, $self->_stream_from_array(
+        @$events, { type => 'CLOSE', name => $evt->{name} }
+      ) ];
     }
-    return $self->_stream_concat($emit, $self->collect->(@_));
+    my $coll = &$coll_proto;
+    my $emit = $self->_stream_from_array(@$events);
+    return [ $coll->[0], $self->_stream_concat($coll->[1], $emit) ];
   };
 }
 
-sub collect {
-  my ($self, $into, $passthrough) = @_;
+sub replace {
+  my ($self, $events, $options) = @_;
+  my $coll_proto = $self->collect($options);
   sub {
     my ($evt, $stream) = @_;
-    push(@$into, $evt) if $into;
-    if ($evt->{is_in_place_close}) {
-      return $evt if $passthrough;
-      return;
-    }
-    my $name = $evt->{name};
-    my $depth = 1;
-    my $collector = $self->_stream_from_code(sub {
-      return unless $stream;
-      while (my ($evt) = $stream->next) {
-        $depth++ if ($evt->{type} eq 'OPEN');
-        $depth-- if ($evt->{type} eq 'CLOSE');
-        unless ($depth) {
-          undef $stream;
-          return $evt if $passthrough;
-          return;
-        }
-        push(@$into, $evt) if $into;
-        return $evt if $passthrough;
-      }
-      die "Never saw closing </${name}> before end of source";
-    });
-    return $passthrough ? [ $evt, $collector ] : $collector;
+    my $emit = $self->_stream_from_array(@$events);
+    my $coll = &$coll_proto;
+    # For a straightforward replace operation we can, in fact, do the emit
+    # -before- the collect, and my first cut did so. However in order to
+    # use the captured content in generating the new content, we need
+    # the collect stage to happen first - and it seems highly unlikely
+    # that in normal operation the collect phase will take long enough
+    # for the difference to be noticeable
+    return
+      ($coll
+        ? (ref $coll eq 'ARRAY'
+            ? [ $coll->[0], $self->_stream_concat($coll->[1], $emit) ]
+            : $self->_stream_concat($coll, $emit)
+          )
+        : $emit
+      );
   };
 }