Update to last common bleve (#3986)

vendor/github.com/couchbase/vellum/regexp/sparse.go

@@ -0,0 +1,54 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package regexp
+
+type sparseSet struct {
+	dense  []uint
+	sparse []uint
+	size   uint
+}
+
+func newSparseSet(size uint) *sparseSet {
+	return &sparseSet{
+		dense:  make([]uint, size),
+		sparse: make([]uint, size),
+		size:   0,
+	}
+}
+
+func (s *sparseSet) Len() int {
+	return int(s.size)
+}
+
+func (s *sparseSet) Add(ip uint) uint {
+	i := s.size
+	s.dense[i] = ip
+	s.sparse[ip] = i
+	s.size++
+	return i
+}
+
+func (s *sparseSet) Get(i uint) uint {
+	return s.dense[i]
+}
+
+func (s *sparseSet) Contains(ip uint) bool {
+	i := s.sparse[ip]
+	return i < s.size && s.dense[i] == ip
+}
+
+func (s *sparseSet) Clear() {
+	s.size = 0
+}