| // Copyright 2019 The Chromium OS Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Package set provides utility set operations. |
| package set |
| |
| // DiffStringSlice returns a - b (where - is the set difference operator). |
| // In other words, it returns all elements of a that are not in b. |
| func DiffStringSlice(a, b []string) []string { |
| om := make(map[string]bool, len(b)) |
| for _, p := range b { |
| om[p] = true |
| } |
| |
| var out []string |
| for _, p := range a { |
| if !om[p] { |
| out = append(out, p) |
| } |
| } |
| return out |
| } |
