JamesMoss\Flywheel\QueryExecuter::filter PHP Method

    protected function filter($documents, $predicates)
    {
        $result = array();
        $originalDocs = $documents;
        $andPredicates = array_filter($predicates, function ($pred) {
            return $pred[0] !== Predicate::LOGICAL_OR;
        });
        $orPredicates = array_filter($predicates, function ($pred) {
            return $pred[0] === Predicate::LOGICAL_OR;
        });
        // 5.3 hack for accessing $this inside closure.
        $self = $this;
        foreach ($andPredicates as $predicate) {
            if (is_array($predicate[1])) {
                $documents = $this->filter($documents, $predicate[1]);
            } else {
                list($type, $field, $operator, $value) = $predicate;
                $documents = array_values(array_filter($documents, function ($doc) use($self, $field, $operator, $value) {
                    return $self->matchDocument($doc, $field, $operator, $value);
                }));
            }
            $result = $documents;
        }
        foreach ($orPredicates as $predicate) {
            if (is_array($predicate[1])) {
                $documents = $this->filter($originalDocs, $predicate[1]);
            } else {
                list($type, $field, $operator, $value) = $predicate;
                $documents = array_values(array_filter($originalDocs, function ($doc) use($self, $field, $operator, $value) {
                    return $self->matchDocument($doc, $field, $operator, $value);
                }));
            }
            $result = array_unique(array_merge($result, $documents), SORT_REGULAR);
        }
        return $result;
    }