ppi_document_for_file

  my $document = $self->ppi_document_for_file($file);

Given a dzil file object (anything that does Dist::Zilla::Role::File), this method returns a new PPI::Document for that file's content.

Internally, this method caches these documents. If multiple plugins want a document for the same file, this avoids reparsing it.

save_ppi_document_to_file

  my $document = $self->save_ppi_document_to_file($document,$file);

Given a PPI::Document and a dzil file object (anything that does Dist::Zilla::Role::File), this method saves the serialized document in the file.

It also updates the internal PPI document cache with the new document.

document_assigns_to_variable

  if( $self->document_assigns_to_variable($document, '$FOO')) { ... }

This method returns true if the document assigns to the given variable (the sigil must be included).