| // Copyright 2013 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // This file implements objsets. |
| // |
| // An objset is similar to a Scope but objset elements |
| // are identified by their unique id, instead of their |
| // object name. |
| |
| package types2 |
| |
| // An objset is a set of objects identified by their unique id. |
| // The zero value for objset is a ready-to-use empty objset. |
| type objset map[string]Object // initialized lazily |
| |
| // insert attempts to insert an object obj into objset s. |
| // If s already contains an alternative object alt with |
| // the same name, insert leaves s unchanged and returns alt. |
| // Otherwise it inserts obj and returns nil. |
| func (s *objset) insert(obj Object) Object { |
| id := obj.Id() |
| if alt := (*s)[id]; alt != nil { |
| return alt |
| } |
| if *s == nil { |
| *s = make(map[string]Object) |
| } |
| (*s)[id] = obj |
| return nil |
| } |