ImmutableMap.h revision 6632f952393834fde26d53ea724ce2a53781d210 
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 {
55public:
56  typedef typename ValInfo::value_type      value_type;
57  typedef typename ValInfo::value_type_ref  value_type_ref;
58  typedef typename ValInfo::key_type        key_type;
59  typedef typename ValInfo::key_type_ref    key_type_ref;
60  typedef typename ValInfo::data_type       data_type;
61  typedef typename ValInfo::data_type_ref   data_type_ref;
62  typedef ImutAVLTree<ValInfo>              TreeTy;
63
64private:
65  TreeTy* Root;
66
67public:
68  /// Constructs a map from a pointer to a tree root.  In general one
69  /// should use a Factory object to create maps instead of directly
70  /// invoking the constructor, but there are cases where make this
71  /// constructor public is useful.
72  explicit ImmutableMap(TreeTy* R) : Root(R) {}
73
74  class Factory {
75    typename TreeTy::Factory F;
76
77  public:
78    Factory() {}
79
80    ImmutableMap GetEmptyMap() { return ImmutableMap(F.GetEmptyTree()); }
81
82    ImmutableMap Add(ImmutableMap Old, key_type_ref K, data_type_ref D) {
83      return ImmutableMap(F.Add(Old.Root,
84                                std::make_pair<key_type,data_type>(K,D)));
85    }
86
87    ImmutableMap Remove(ImmutableMap Old, key_type_ref K) {
88      return ImmutableMap(F.Remove(Old.Root,K));
89    }
90
91  private:
92    Factory(const Factory& RHS) {};
93    void operator=(const Factory& RHS) {};
94  };
95
96  friend class Factory;
97
98  bool contains(key_type_ref K) const {
99    return Root ? Root->contains(K) : false;
100  }
101
102  data_type* find(key_type_ref K) const {
103    if (Root) {
104      TreeTy* T = Root->find(K);
105      if (T) return &T->getValue().second;
106    }
107
108    return NULL;
109  }
110
111  bool operator==(ImmutableMap RHS) const {
112    return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
113  }
114
115  bool operator!=(ImmutableMap RHS) const {
116    return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
117  }
118
119  TreeTy* getRoot() const { return Root; }
120
121  bool isEmpty() const { return !Root; }
122
123  //===--------------------------------------------------===//
124  // Foreach - A limited form of map iteration.
125  //===--------------------------------------------------===//
126
127private:
128  template <typename Callback>
129  struct CBWrapper {
130    Callback C;
131    void operator()(value_type_ref V) { C(V.first,V.second); }
132  };
133
134  template <typename Callback>
135  struct CBWrapperRef {
136    Callback &C;
137    CBWrapperRef(Callback& c) : C(c) {}
138
139    void operator()(value_type_ref V) { C(V.first,V.second); }
140  };
141
142public:
143  template <typename Callback>
144  void foreach(Callback& C) {
145    if (Root) {
146      CBWrapperRef<Callback> CB(C);
147      Root->foreach(CB);
148    }
149  }
150
151  template <typename Callback>
152  void foreach() {
153    if (Root) {
154      CBWrapper<Callback> CB;
155      Root->foreach(CB);
156    }
157  }
158
159  //===--------------------------------------------------===//
160  // For testing.
161  //===--------------------------------------------------===//
162
163  void verify() const { if (Root) Root->verify(); }
164
165  //===--------------------------------------------------===//
166  // Iterators.
167  //===--------------------------------------------------===//
168
169  class iterator {
170    typename TreeTy::iterator itr;
171
172    iterator() {}
173    iterator(TreeTy* t) : itr(t) {}
174    friend class ImmutableSet<ValT,ValInfo>;
175
176  public:
177    inline value_type_ref operator*() const { return itr->getValue(); }
178    inline key_type_ref getKey() const { return itr->getValue().first; }
179    inline data_type_ref getData() const { return itr->getValue().second; }
180
181    inline iterator& operator++() { ++itr; return *this; }
182    inline iterator  operator++(int) { iterator tmp(*this); ++itr; return tmp; }
183    inline iterator& operator--() { --itr; return *this; }
184    inline iterator  operator--(int) { iterator tmp(*this); --itr; return tmp; }
185    inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; }
186    inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; }
187  };
188
189  iterator begin() const { return iterator(Root); }
190  iterator end() const { return iterator(); }
191
192  //===--------------------------------------------------===//
193  // Utility methods.
194  //===--------------------------------------------------===//
195
196  inline unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
197
198  static inline void Profile(FoldingSetNodeID& ID, const ImmutableMap& M) {
199    ID.AddPointer(M.Root);
200  }
201
202  inline void Profile(FoldingSetNodeID& ID) const {
203    return Profile(ID,*this);
204  }
205};
206
207} // end namespace llvm
208
209#endif
210