ImmutableMap.h revision 0a8cabb17892746ba71a94f494a5d293a716edfd 
1//===--- ImmutableMap.h - Immutable (functional) map interface --*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the ImmutableMap class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ADT_IMMAP_H
15#define LLVM_ADT_IMMAP_H
16
17#include "llvm/ADT/ImmutableSet.h"
18
19namespace llvm {
20
21/// ImutKeyValueInfo -Traits class used by ImmutableMap.  While both the first and
22/// second elements in a pair are used to generate profile information,
23/// only the first element (the key) is used by isEqual and isLess.
24template <typename T, typename S>
25struct ImutKeyValueInfo {
26  typedef const std::pair<T,S> value_type;
27  typedef const value_type& value_type_ref;
28  typedef const T   key_type;
29  typedef const T&  key_type_ref;
30  typedef const S   data_type;
31  typedef const S&  data_type_ref;
32
33  static inline key_type_ref KeyOfValue(value_type_ref V) {
34    return V.first;
35  }
36
37  static inline bool isEqual(key_type_ref L, key_type_ref R) {
38    return ImutContainerInfo<T>::isEqual(L,R);
39  }
40
41  static inline bool isLess(key_type_ref L, key_type_ref R) {
42    return ImutContainerInfo<T>::isLess(L,R);
43  }
44
45  static inline void Profile(FoldingSetNodeID& ID, value_type_ref V) {
46    ImutContainerInfo<T>::Profile(ID, V.first);
47    ImutContainerInfo<S>::Profile(ID, V.second);
48  }
49};
50
51
52template <typename KeyT, typename ValT,
53          typename ValInfo = ImutKeyValueInfo<KeyT,ValT> >
54class ImmutableMap {
55  typedef typename ValInfo::value_type      value_type;
56  typedef typename ValInfo::value_type_ref  value_type_ref;
57  typedef typename ValInfo::key_type        key_type;
58  typedef typename ValInfo::key_type_ref    key_type_ref;
59  typedef typename ValInfo::data_type       data_type;
60  typedef typename ValInfo::data_type_ref   data_type_ref;
61
62private:
63  typedef ImutAVLTree<ValInfo> TreeTy;
64  TreeTy* Root;
65
66  ImmutableMap(TreeTy* R) : Root(R) {}
67
68public:
69
70  class Factory {
71    typename TreeTy::Factory F;
72
73  public:
74    Factory() {}
75
76    ImmutableMap GetEmptyMap() { return ImmutableMap(F.GetEmptyTree()); }
77
78    ImmutableMap Add(ImmutableMap Old, key_type_ref K, data_type_ref D) {
79      return ImmutableMap(F.Add(Old.Root,
80                                std::make_pair<key_type,data_type>(K,D)));
81    }
82
83    ImmutableMap Remove(ImmutableMap Old, key_type_ref K) {
84      return ImmutableMap(F.Remove(Old.Root,K));
85    }
86
87  private:
88    Factory(const Factory& RHS) {};
89    void operator=(const Factory& RHS) {};
90  };
91
92  friend class Factory;
93
94  bool contains(key_type_ref K) const {
95    return Root ? Root->contains(K) : false;
96  }
97
98  data_type* find(key_type_ref K) const {
99    if (Root) {
100      TreeTy* T = Root->find(K);
101      if (T) return &T->getValue().second;
102    }
103
104    return NULL;
105  }
106
107  bool operator==(ImmutableMap RHS) const {
108    return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
109  }
110
111  bool operator!=(ImmutableMap RHS) const {
112    return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
113  }
114
115  bool isEmpty() const { return !Root; }
116
117  //===--------------------------------------------------===//
118  // Foreach - A limited form of map iteration.
119  //===--------------------------------------------------===//
120
121private:
122  template <typename Callback>
123  struct CBWrapper {
124    Callback C;
125    void operator()(value_type_ref V) { C(V.first,V.second); }
126  };
127
128  template <typename Callback>
129  struct CBWrapperRef {
130    Callback &C;
131    CBWrapperRef(Callback& c) : C(c) {}
132
133    void operator()(value_type_ref V) { C(V.first,V.second); }
134  };
135
136public:
137  template <typename Callback>
138  void foreach(Callback& C) {
139    if (Root) {
140      CBWrapperRef<Callback> CB(C);
141      Root->foreach(CB);
142    }
143  }
144
145  template <typename Callback>
146  void foreach() {
147    if (Root) {
148      CBWrapper<Callback> CB;
149      Root->foreach(CB);
150    }
151  }
152
153  //===--------------------------------------------------===//
154  // For testing.
155  //===--------------------------------------------------===//
156
157  void verify() const { if (Root) Root->verify(); }
158
159  //===--------------------------------------------------===//
160  // Iterators.
161  //===--------------------------------------------------===//
162
163  class iterator {
164    typename TreeTy::iterator itr;
165
166    iterator() {}
167    iterator(TreeTy* t) : itr(t) {}
168    friend class ImmutableSet<ValT,ValInfo>;
169
170  public:
171    inline value_type_ref operator*() const { return itr->getValue(); }
172    inline key_type_ref getKey() const { return itr->getValue().first; }
173    inline data_type_ref getData() const { return itr->getValue().second; }
174
175    inline iterator& operator++() { ++itr; return *this; }
176    inline iterator  operator++(int) { iterator tmp(*this); ++itr; return tmp; }
177    inline iterator& operator--() { --itr; return *this; }
178    inline iterator  operator--(int) { iterator tmp(*this); --itr; return tmp; }
179    inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; }
180    inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; }
181  };
182
183  iterator begin() const { return iterator(Root); }
184  iterator end() const { return iterator(); }
185
186  //===--------------------------------------------------===//
187  // Utility methods.
188  //===--------------------------------------------------===//
189
190  inline unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
191
192  static inline void Profile(FoldingSetNodeID& ID, const ImmutableMap& M) {
193    ID.AddPointer(M.Root);
194  }
195
196  inline void Profile(FoldingSetNodeID& ID) const {
197    return Profile(ID,*this);
198  }
199};
200
201} // end namespace llvm
202
203#endif
204