1 // Copyright 2013 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // This file implements objsets. 6 // 7 // An objset is similar to a Scope but objset elements 8 // are identified by their unique id, instead of their 9 // object name. 10 11 package types 12 13 // An objset is a set of objects identified by their unique id. 14 // The zero value for objset is a ready-to-use empty objset. 15 type objset map[string]Object // initialized lazily 16 17 // insert attempts to insert an object obj into objset s. 18 // If s already contains an alternative object alt with 19 // the same name, insert leaves s unchanged and returns alt. 20 // Otherwise it inserts obj and returns nil. 21 func (s *objset) insert(obj Object) Object { 22 id := obj.Id() 23 if alt := (*s)[id]; alt != nil { 24 return alt 25 } 26 if *s == nil { 27 *s = make(map[string]Object) 28 } 29 (*s)[id] = obj 30 return nil 31 } 32