1 //===--- ImmutableSet.h - Immutable (functional) set interface --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the ImutAVLTree and ImmutableSet classes.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ADT_IMSET_H
15 #define LLVM_ADT_IMSET_H
17 #include "llvm/Support/Allocator.h"
18 #include "llvm/ADT/FoldingSet.h"
19 #include "llvm/System/DataTypes.h"
25 //===----------------------------------------------------------------------===//
26 // Immutable AVL-Tree Definition.
27 //===----------------------------------------------------------------------===//
29 template <typename ImutInfo> class ImutAVLFactory;
30 template <typename ImutInfo> class ImutIntervalAVLFactory;
31 template <typename ImutInfo> class ImutAVLTreeInOrderIterator;
32 template <typename ImutInfo> class ImutAVLTreeGenericIterator;
34 template <typename ImutInfo >
35 class ImutAVLTree : public FoldingSetNode {
37 typedef typename ImutInfo::key_type_ref key_type_ref;
38 typedef typename ImutInfo::value_type value_type;
39 typedef typename ImutInfo::value_type_ref value_type_ref;
41 typedef ImutAVLFactory<ImutInfo> Factory;
42 friend class ImutAVLFactory<ImutInfo>;
43 friend class ImutIntervalAVLFactory<ImutInfo>;
45 friend class ImutAVLTreeGenericIterator<ImutInfo>;
46 friend class FoldingSet<ImutAVLTree>;
48 typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator;
50 //===----------------------------------------------------===//
52 //===----------------------------------------------------===//
54 /// getLeft - Returns a pointer to the left subtree. This value
55 /// is NULL if there is no left subtree.
56 ImutAVLTree *getLeft() const { return Left; }
58 /// getRight - Returns a pointer to the right subtree. This value is
59 /// NULL if there is no right subtree.
60 ImutAVLTree *getRight() const { return Right; }
62 /// getHeight - Returns the height of the tree. A tree with no subtrees
63 /// has a height of 1.
64 unsigned getHeight() const { return Height; }
66 /// getValue - Returns the data value associated with the tree node.
67 const value_type& getValue() const { return Value; }
69 /// find - Finds the subtree associated with the specified key value.
70 /// This method returns NULL if no matching subtree is found.
71 ImutAVLTree* find(key_type_ref K) {
72 ImutAVLTree *T = this;
75 key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue());
77 if (ImutInfo::isEqual(K,CurrentKey))
79 else if (ImutInfo::isLess(K,CurrentKey))
88 /// getMaxElement - Find the subtree associated with the highest ranged
90 ImutAVLTree* getMaxElement() {
91 ImutAVLTree *T = this;
92 ImutAVLTree *Right = T->getRight();
93 while (Right) { T = Right; Right = T->getRight(); }
97 /// size - Returns the number of nodes in the tree, which includes
98 /// both leaves and non-leaf nodes.
99 unsigned size() const {
102 if (const ImutAVLTree* L = getLeft()) n += L->size();
103 if (const ImutAVLTree* R = getRight()) n += R->size();
108 /// begin - Returns an iterator that iterates over the nodes of the tree
109 /// in an inorder traversal. The returned iterator thus refers to the
110 /// the tree node with the minimum data element.
111 iterator begin() const { return iterator(this); }
113 /// end - Returns an iterator for the tree that denotes the end of an
114 /// inorder traversal.
115 iterator end() const { return iterator(); }
117 bool ElementEqual(value_type_ref V) const {
119 if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(getValue()),
120 ImutInfo::KeyOfValue(V)))
123 // Also compare the data values.
124 if (!ImutInfo::isDataEqual(ImutInfo::DataOfValue(getValue()),
125 ImutInfo::DataOfValue(V)))
131 bool ElementEqual(const ImutAVLTree* RHS) const {
132 return ElementEqual(RHS->getValue());
135 /// isEqual - Compares two trees for structural equality and returns true
136 /// if they are equal. This worst case performance of this operation is
137 // linear in the sizes of the trees.
138 bool isEqual(const ImutAVLTree& RHS) const {
142 iterator LItr = begin(), LEnd = end();
143 iterator RItr = RHS.begin(), REnd = RHS.end();
145 while (LItr != LEnd && RItr != REnd) {
146 if (*LItr == *RItr) {
152 if (!LItr->ElementEqual(*RItr))
159 return LItr == LEnd && RItr == REnd;
162 /// isNotEqual - Compares two trees for structural inequality. Performance
163 /// is the same is isEqual.
164 bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); }
166 /// contains - Returns true if this tree contains a subtree (node) that
167 /// has an data element that matches the specified key. Complexity
168 /// is logarithmic in the size of the tree.
169 bool contains(key_type_ref K) { return (bool) find(K); }
171 /// foreach - A member template the accepts invokes operator() on a functor
172 /// object (specifed by Callback) for every node/subtree in the tree.
173 /// Nodes are visited using an inorder traversal.
174 template <typename Callback>
175 void foreach(Callback& C) {
176 if (ImutAVLTree* L = getLeft()) L->foreach(C);
180 if (ImutAVLTree* R = getRight()) R->foreach(C);
183 /// verify - A utility method that checks that the balancing and
184 /// ordering invariants of the tree are satisifed. It is a recursive
185 /// method that returns the height of the tree, which is then consumed
186 /// by the enclosing verify call. External callers should ignore the
187 /// return value. An invalid tree will cause an assertion to fire in
189 unsigned verify() const {
190 unsigned HL = getLeft() ? getLeft()->verify() : 0;
191 unsigned HR = getRight() ? getRight()->verify() : 0;
193 assert(getHeight() == ( HL > HR ? HL : HR ) + 1
194 && "Height calculation wrong");
196 assert((HL > HR ? HL-HR : HR-HL) <= 2
197 && "Balancing invariant violated");
200 || ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()),
201 ImutInfo::KeyOfValue(getValue()))
202 && "Value in left child is not less that current value");
206 || ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()),
207 ImutInfo::KeyOfValue(getRight()->getValue()))
208 && "Current value is not less that value of right child");
213 /// Profile - Profiling for ImutAVLTree.
214 void Profile(llvm::FoldingSetNodeID& ID) {
215 ID.AddInteger(ComputeDigest());
218 //===----------------------------------------------------===//
220 //===----------------------------------------------------===//
225 unsigned Height : 28;
226 unsigned Mutable : 1;
227 unsigned CachedDigest : 1;
231 //===----------------------------------------------------===//
232 // Internal methods (node manipulation; used by Factory).
233 //===----------------------------------------------------===//
236 /// ImutAVLTree - Internal constructor that is only called by
238 ImutAVLTree(ImutAVLTree* l, ImutAVLTree* r, value_type_ref v,
240 : Left(l), Right(r), Height(height), Mutable(true), CachedDigest(false),
241 Value(v), Digest(0) {}
243 /// isMutable - Returns true if the left and right subtree references
244 /// (as well as height) can be changed. If this method returns false,
245 /// the tree is truly immutable. Trees returned from an ImutAVLFactory
246 /// object should always have this method return true. Further, if this
247 /// method returns false for an instance of ImutAVLTree, all subtrees
248 /// will also have this method return false. The converse is not true.
249 bool isMutable() const { return Mutable; }
251 /// hasCachedDigest - Returns true if the digest for this tree is cached.
252 /// This can only be true if the tree is immutable.
253 bool hasCachedDigest() const { return CachedDigest; }
255 //===----------------------------------------------------===//
256 // Mutating operations. A tree root can be manipulated as
257 // long as its reference has not "escaped" from internal
258 // methods of a factory object (see below). When a tree
259 // pointer is externally viewable by client code, the
260 // internal "mutable bit" is cleared to mark the tree
261 // immutable. Note that a tree that still has its mutable
262 // bit set may have children (subtrees) that are themselves
264 //===----------------------------------------------------===//
266 /// MarkImmutable - Clears the mutable flag for a tree. After this happens,
267 /// it is an error to call setLeft(), setRight(), and setHeight().
268 void MarkImmutable() {
269 assert(isMutable() && "Mutable flag already removed.");
273 /// MarkedCachedDigest - Clears the NoCachedDigest flag for a tree.
274 void MarkedCachedDigest() {
275 assert(!hasCachedDigest() && "NoCachedDigest flag already removed.");
279 /// setLeft - Changes the reference of the left subtree. Used internally
280 /// by ImutAVLFactory.
281 void setLeft(ImutAVLTree* NewLeft) {
282 assert(isMutable() &&
283 "Only a mutable tree can have its left subtree changed.");
285 CachedDigest = false;
288 /// setRight - Changes the reference of the right subtree. Used internally
289 /// by ImutAVLFactory.
290 void setRight(ImutAVLTree* NewRight) {
291 assert(isMutable() &&
292 "Only a mutable tree can have its right subtree changed.");
295 CachedDigest = false;
298 /// setHeight - Changes the height of the tree. Used internally by
300 void setHeight(unsigned h) {
301 assert(isMutable() && "Only a mutable tree can have its height changed.");
306 uint32_t ComputeDigest(ImutAVLTree* L, ImutAVLTree* R, value_type_ref V) {
310 digest += L->ComputeDigest();
312 // Compute digest of stored data.
314 ImutInfo::Profile(ID,V);
315 digest += ID.ComputeHash();
318 digest += R->ComputeDigest();
323 inline uint32_t ComputeDigest() {
324 // Check the lowest bit to determine if digest has actually been
326 if (hasCachedDigest())
329 uint32_t X = ComputeDigest(getLeft(), getRight(), getValue());
331 MarkedCachedDigest();
336 //===----------------------------------------------------------------------===//
337 // Immutable AVL-Tree Factory class.
338 //===----------------------------------------------------------------------===//
340 template <typename ImutInfo >
341 class ImutAVLFactory {
342 typedef ImutAVLTree<ImutInfo> TreeTy;
343 typedef typename TreeTy::value_type_ref value_type_ref;
344 typedef typename TreeTy::key_type_ref key_type_ref;
346 typedef FoldingSet<TreeTy> CacheTy;
351 bool ownsAllocator() const {
352 return Allocator & 0x1 ? false : true;
355 BumpPtrAllocator& getAllocator() const {
356 return *reinterpret_cast<BumpPtrAllocator*>(Allocator & ~0x1);
359 //===--------------------------------------------------===//
361 //===--------------------------------------------------===//
365 : Allocator(reinterpret_cast<uintptr_t>(new BumpPtrAllocator())) {}
367 ImutAVLFactory(BumpPtrAllocator& Alloc)
368 : Allocator(reinterpret_cast<uintptr_t>(&Alloc) | 0x1) {}
371 if (ownsAllocator()) delete &getAllocator();
374 TreeTy* Add(TreeTy* T, value_type_ref V) {
375 T = Add_internal(V,T);
380 TreeTy* Remove(TreeTy* T, key_type_ref V) {
381 T = Remove_internal(V,T);
386 TreeTy* GetEmptyTree() const { return NULL; }
388 //===--------------------------------------------------===//
389 // A bunch of quick helper functions used for reasoning
390 // about the properties of trees and their children.
391 // These have succinct names so that the balancing code
392 // is as terse (and readable) as possible.
393 //===--------------------------------------------------===//
396 bool isEmpty(TreeTy* T) const { return !T; }
397 unsigned Height(TreeTy* T) const { return T ? T->getHeight() : 0; }
398 TreeTy* Left(TreeTy* T) const { return T->getLeft(); }
399 TreeTy* Right(TreeTy* T) const { return T->getRight(); }
400 value_type_ref Value(TreeTy* T) const { return T->Value; }
402 unsigned IncrementHeight(TreeTy* L, TreeTy* R) const {
403 unsigned hl = Height(L);
404 unsigned hr = Height(R);
405 return (hl > hr ? hl : hr) + 1;
408 static bool CompareTreeWithSection(TreeTy* T,
409 typename TreeTy::iterator& TI,
410 typename TreeTy::iterator& TE) {
412 typename TreeTy::iterator I = T->begin(), E = T->end();
414 for ( ; I!=E ; ++I, ++TI)
415 if (TI == TE || !I->ElementEqual(*TI))
421 //===--------------------------------------------------===//
422 // "CreateNode" is used to generate new tree roots that link
423 // to other trees. The functon may also simply move links
424 // in an existing root if that root is still marked mutable.
425 // This is necessary because otherwise our balancing code
426 // would leak memory as it would create nodes that are
427 // then discarded later before the finished tree is
428 // returned to the caller.
429 //===--------------------------------------------------===//
431 TreeTy* CreateNode(TreeTy* L, value_type_ref V, TreeTy* R) {
432 BumpPtrAllocator& A = getAllocator();
433 TreeTy* T = (TreeTy*) A.Allocate<TreeTy>();
434 new (T) TreeTy(L, R, V, IncrementHeight(L,R));
438 TreeTy* CreateNode(TreeTy* L, TreeTy* OldTree, TreeTy* R) {
439 assert(!isEmpty(OldTree));
441 if (OldTree->isMutable()) {
443 OldTree->setRight(R);
444 OldTree->setHeight(IncrementHeight(L, R));
448 return CreateNode(L, Value(OldTree), R);
451 /// Balance - Used by Add_internal and Remove_internal to
452 /// balance a newly created tree.
453 TreeTy* Balance(TreeTy* L, value_type_ref V, TreeTy* R) {
455 unsigned hl = Height(L);
456 unsigned hr = Height(R);
459 assert(!isEmpty(L) && "Left tree cannot be empty to have a height >= 2");
461 TreeTy* LL = Left(L);
462 TreeTy* LR = Right(L);
464 if (Height(LL) >= Height(LR))
465 return CreateNode(LL, L, CreateNode(LR,V,R));
467 assert(!isEmpty(LR) && "LR cannot be empty because it has a height >= 1");
469 TreeTy* LRL = Left(LR);
470 TreeTy* LRR = Right(LR);
472 return CreateNode(CreateNode(LL,L,LRL), LR, CreateNode(LRR,V,R));
474 else if (hr > hl + 2) {
475 assert(!isEmpty(R) && "Right tree cannot be empty to have a height >= 2");
477 TreeTy* RL = Left(R);
478 TreeTy* RR = Right(R);
480 if (Height(RR) >= Height(RL))
481 return CreateNode(CreateNode(L,V,RL), R, RR);
483 assert(!isEmpty(RL) && "RL cannot be empty because it has a height >= 1");
485 TreeTy* RLL = Left(RL);
486 TreeTy* RLR = Right(RL);
488 return CreateNode(CreateNode(L,V,RLL), RL, CreateNode(RLR,R,RR));
491 return CreateNode(L,V,R);
494 /// Add_internal - Creates a new tree that includes the specified
495 /// data and the data from the original tree. If the original tree
496 /// already contained the data item, the original tree is returned.
497 TreeTy* Add_internal(value_type_ref V, TreeTy* T) {
499 return CreateNode(T, V, T);
501 assert(!T->isMutable());
503 key_type_ref K = ImutInfo::KeyOfValue(V);
504 key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
506 if (ImutInfo::isEqual(K,KCurrent))
507 return CreateNode(Left(T), V, Right(T));
508 else if (ImutInfo::isLess(K,KCurrent))
509 return Balance(Add_internal(V,Left(T)), Value(T), Right(T));
511 return Balance(Left(T), Value(T), Add_internal(V,Right(T)));
514 /// Remove_internal - Creates a new tree that includes all the data
515 /// from the original tree except the specified data. If the
516 /// specified data did not exist in the original tree, the original
517 /// tree is returned.
518 TreeTy* Remove_internal(key_type_ref K, TreeTy* T) {
522 assert(!T->isMutable());
524 key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
526 if (ImutInfo::isEqual(K,KCurrent))
527 return CombineLeftRightTrees(Left(T),Right(T));
528 else if (ImutInfo::isLess(K,KCurrent))
529 return Balance(Remove_internal(K,Left(T)), Value(T), Right(T));
531 return Balance(Left(T), Value(T), Remove_internal(K,Right(T)));
534 TreeTy* CombineLeftRightTrees(TreeTy* L, TreeTy* R) {
535 if (isEmpty(L)) return R;
536 if (isEmpty(R)) return L;
539 TreeTy* NewRight = RemoveMinBinding(R,OldNode);
540 return Balance(L,Value(OldNode),NewRight);
543 TreeTy* RemoveMinBinding(TreeTy* T, TreeTy*& NodeRemoved) {
546 if (isEmpty(Left(T))) {
551 return Balance(RemoveMinBinding(Left(T),NodeRemoved),Value(T),Right(T));
554 /// MarkImmutable - Clears the mutable bits of a root and all of its
556 void MarkImmutable(TreeTy* T) {
557 if (!T || !T->isMutable())
561 MarkImmutable(Left(T));
562 MarkImmutable(Right(T));
566 TreeTy *GetCanonicalTree(TreeTy *TNew) {
570 // Search the FoldingSet bucket for a Tree with the same digest.
572 unsigned digest = TNew->ComputeDigest();
573 ID.AddInteger(digest);
574 unsigned hash = ID.ComputeHash();
576 typename CacheTy::bucket_iterator I = Cache.bucket_begin(hash);
577 typename CacheTy::bucket_iterator E = Cache.bucket_end(hash);
579 for (; I != E; ++I) {
582 if (T->ComputeDigest() != digest)
585 // We found a collision. Perform a comparison of Contents('T')
586 // with Contents('TNew')
587 typename TreeTy::iterator TI = T->begin(), TE = T->end();
589 if (!CompareTreeWithSection(TNew, TI, TE))
593 continue; // T has more contents than TNew.
595 // Trees did match! Return 'T'.
599 // 'TNew' is the only tree of its kind. Return it.
600 Cache.InsertNode(TNew, (void*) &*Cache.bucket_end(hash));
606 //===----------------------------------------------------------------------===//
607 // Immutable AVL-Tree Iterators.
608 //===----------------------------------------------------------------------===//
610 template <typename ImutInfo>
611 class ImutAVLTreeGenericIterator {
612 SmallVector<uintptr_t,20> stack;
614 enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3,
617 typedef ImutAVLTree<ImutInfo> TreeTy;
618 typedef ImutAVLTreeGenericIterator<ImutInfo> _Self;
620 inline ImutAVLTreeGenericIterator() {}
621 inline ImutAVLTreeGenericIterator(const TreeTy* Root) {
622 if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root));
625 TreeTy* operator*() const {
626 assert(!stack.empty());
627 return reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
630 uintptr_t getVisitState() {
631 assert(!stack.empty());
632 return stack.back() & Flags;
636 bool AtEnd() const { return stack.empty(); }
638 bool AtBeginning() const {
639 return stack.size() == 1 && getVisitState() == VisitedNone;
642 void SkipToParent() {
643 assert(!stack.empty());
649 switch (getVisitState()) {
651 stack.back() |= VisitedLeft;
654 stack.back() |= VisitedRight;
657 assert(false && "Unreachable.");
661 inline bool operator==(const _Self& x) const {
662 if (stack.size() != x.stack.size())
665 for (unsigned i = 0 ; i < stack.size(); i++)
666 if (stack[i] != x.stack[i])
672 inline bool operator!=(const _Self& x) const { return !operator==(x); }
674 _Self& operator++() {
675 assert(!stack.empty());
677 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
680 switch (getVisitState()) {
682 if (TreeTy* L = Current->getLeft())
683 stack.push_back(reinterpret_cast<uintptr_t>(L));
685 stack.back() |= VisitedLeft;
690 if (TreeTy* R = Current->getRight())
691 stack.push_back(reinterpret_cast<uintptr_t>(R));
693 stack.back() |= VisitedRight;
702 assert(false && "Unreachable.");
708 _Self& operator--() {
709 assert(!stack.empty());
711 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
714 switch (getVisitState()) {
720 stack.back() &= ~Flags; // Set state to "VisitedNone."
722 if (TreeTy* L = Current->getLeft())
723 stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight);
728 stack.back() &= ~Flags;
729 stack.back() |= VisitedLeft;
731 if (TreeTy* R = Current->getRight())
732 stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight);
737 assert(false && "Unreachable.");
744 template <typename ImutInfo>
745 class ImutAVLTreeInOrderIterator {
746 typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy;
747 InternalIteratorTy InternalItr;
750 typedef ImutAVLTree<ImutInfo> TreeTy;
751 typedef ImutAVLTreeInOrderIterator<ImutInfo> _Self;
753 ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) {
754 if (Root) operator++(); // Advance to first element.
757 ImutAVLTreeInOrderIterator() : InternalItr() {}
759 inline bool operator==(const _Self& x) const {
760 return InternalItr == x.InternalItr;
763 inline bool operator!=(const _Self& x) const { return !operator==(x); }
765 inline TreeTy* operator*() const { return *InternalItr; }
766 inline TreeTy* operator->() const { return *InternalItr; }
768 inline _Self& operator++() {
770 while (!InternalItr.AtEnd() &&
771 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
776 inline _Self& operator--() {
778 while (!InternalItr.AtBeginning() &&
779 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
784 inline void SkipSubTree() {
785 InternalItr.SkipToParent();
787 while (!InternalItr.AtEnd() &&
788 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft)
793 //===----------------------------------------------------------------------===//
794 // Trait classes for Profile information.
795 //===----------------------------------------------------------------------===//
797 /// Generic profile template. The default behavior is to invoke the
798 /// profile method of an object. Specializations for primitive integers
799 /// and generic handling of pointers is done below.
800 template <typename T>
801 struct ImutProfileInfo {
802 typedef const T value_type;
803 typedef const T& value_type_ref;
805 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
806 FoldingSetTrait<T>::Profile(X,ID);
810 /// Profile traits for integers.
811 template <typename T>
812 struct ImutProfileInteger {
813 typedef const T value_type;
814 typedef const T& value_type_ref;
816 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
821 #define PROFILE_INTEGER_INFO(X)\
822 template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {};
824 PROFILE_INTEGER_INFO(char)
825 PROFILE_INTEGER_INFO(unsigned char)
826 PROFILE_INTEGER_INFO(short)
827 PROFILE_INTEGER_INFO(unsigned short)
828 PROFILE_INTEGER_INFO(unsigned)
829 PROFILE_INTEGER_INFO(signed)
830 PROFILE_INTEGER_INFO(long)
831 PROFILE_INTEGER_INFO(unsigned long)
832 PROFILE_INTEGER_INFO(long long)
833 PROFILE_INTEGER_INFO(unsigned long long)
835 #undef PROFILE_INTEGER_INFO
837 /// Generic profile trait for pointer types. We treat pointers as
838 /// references to unique objects.
839 template <typename T>
840 struct ImutProfileInfo<T*> {
841 typedef const T* value_type;
842 typedef value_type value_type_ref;
844 static inline void Profile(FoldingSetNodeID &ID, value_type_ref X) {
849 //===----------------------------------------------------------------------===//
850 // Trait classes that contain element comparison operators and type
851 // definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These
852 // inherit from the profile traits (ImutProfileInfo) to include operations
853 // for element profiling.
854 //===----------------------------------------------------------------------===//
857 /// ImutContainerInfo - Generic definition of comparison operations for
858 /// elements of immutable containers that defaults to using
859 /// std::equal_to<> and std::less<> to perform comparison of elements.
860 template <typename T>
861 struct ImutContainerInfo : public ImutProfileInfo<T> {
862 typedef typename ImutProfileInfo<T>::value_type value_type;
863 typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref;
864 typedef value_type key_type;
865 typedef value_type_ref key_type_ref;
866 typedef bool data_type;
867 typedef bool data_type_ref;
869 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
870 static inline data_type_ref DataOfValue(value_type_ref) { return true; }
872 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
873 return std::equal_to<key_type>()(LHS,RHS);
876 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
877 return std::less<key_type>()(LHS,RHS);
880 static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; }
883 /// ImutContainerInfo - Specialization for pointer values to treat pointers
884 /// as references to unique objects. Pointers are thus compared by
886 template <typename T>
887 struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> {
888 typedef typename ImutProfileInfo<T*>::value_type value_type;
889 typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref;
890 typedef value_type key_type;
891 typedef value_type_ref key_type_ref;
892 typedef bool data_type;
893 typedef bool data_type_ref;
895 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
896 static inline data_type_ref DataOfValue(value_type_ref) { return true; }
898 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
902 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
906 static inline bool isDataEqual(data_type_ref,data_type_ref) { return true; }
909 //===----------------------------------------------------------------------===//
911 //===----------------------------------------------------------------------===//
913 template <typename ValT, typename ValInfo = ImutContainerInfo<ValT> >
916 typedef typename ValInfo::value_type value_type;
917 typedef typename ValInfo::value_type_ref value_type_ref;
918 typedef ImutAVLTree<ValInfo> TreeTy;
924 /// Constructs a set from a pointer to a tree root. In general one
925 /// should use a Factory object to create sets instead of directly
926 /// invoking the constructor, but there are cases where make this
927 /// constructor public is useful.
928 explicit ImmutableSet(TreeTy* R) : Root(R) {}
931 typename TreeTy::Factory F;
932 const bool Canonicalize;
935 Factory(bool canonicalize = true)
936 : Canonicalize(canonicalize) {}
938 Factory(BumpPtrAllocator& Alloc, bool canonicalize = true)
939 : F(Alloc), Canonicalize(canonicalize) {}
941 /// GetEmptySet - Returns an immutable set that contains no elements.
942 ImmutableSet GetEmptySet() {
943 return ImmutableSet(F.GetEmptyTree());
946 /// Add - Creates a new immutable set that contains all of the values
947 /// of the original set with the addition of the specified value. If
948 /// the original set already included the value, then the original set is
949 /// returned and no memory is allocated. The time and space complexity
950 /// of this operation is logarithmic in the size of the original set.
951 /// The memory allocated to represent the set is released when the
952 /// factory object that created the set is destroyed.
953 ImmutableSet Add(ImmutableSet Old, value_type_ref V) {
954 TreeTy *NewT = F.Add(Old.Root, V);
955 return ImmutableSet(Canonicalize ? F.GetCanonicalTree(NewT) : NewT);
958 /// Remove - Creates a new immutable set that contains all of the values
959 /// of the original set with the exception of the specified value. If
960 /// the original set did not contain the value, the original set is
961 /// returned and no memory is allocated. The time and space complexity
962 /// of this operation is logarithmic in the size of the original set.
963 /// The memory allocated to represent the set is released when the
964 /// factory object that created the set is destroyed.
965 ImmutableSet Remove(ImmutableSet Old, value_type_ref V) {
966 TreeTy *NewT = F.Remove(Old.Root, V);
967 return ImmutableSet(Canonicalize ? F.GetCanonicalTree(NewT) : NewT);
970 BumpPtrAllocator& getAllocator() { return F.getAllocator(); }
973 Factory(const Factory& RHS); // DO NOT IMPLEMENT
974 void operator=(const Factory& RHS); // DO NOT IMPLEMENT
977 friend class Factory;
979 /// contains - Returns true if the set contains the specified value.
980 bool contains(value_type_ref V) const {
981 return Root ? Root->contains(V) : false;
984 bool operator==(ImmutableSet RHS) const {
985 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
988 bool operator!=(ImmutableSet RHS) const {
989 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
996 /// isEmpty - Return true if the set contains no elements.
997 bool isEmpty() const { return !Root; }
999 /// isSingleton - Return true if the set contains exactly one element.
1000 /// This method runs in constant time.
1001 bool isSingleton() const { return getHeight() == 1; }
1003 template <typename Callback>
1004 void foreach(Callback& C) { if (Root) Root->foreach(C); }
1006 template <typename Callback>
1007 void foreach() { if (Root) { Callback C; Root->foreach(C); } }
1009 //===--------------------------------------------------===//
1011 //===--------------------------------------------------===//
1014 typename TreeTy::iterator itr;
1015 iterator(TreeTy* t) : itr(t) {}
1016 friend class ImmutableSet<ValT,ValInfo>;
1019 inline value_type_ref operator*() const { return itr->getValue(); }
1020 inline iterator& operator++() { ++itr; return *this; }
1021 inline iterator operator++(int) { iterator tmp(*this); ++itr; return tmp; }
1022 inline iterator& operator--() { --itr; return *this; }
1023 inline iterator operator--(int) { iterator tmp(*this); --itr; return tmp; }
1024 inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; }
1025 inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; }
1026 inline value_type *operator->() const { return &(operator*()); }
1029 iterator begin() const { return iterator(Root); }
1030 iterator end() const { return iterator(); }
1032 //===--------------------------------------------------===//
1034 //===--------------------------------------------------===//
1036 unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
1038 static inline void Profile(FoldingSetNodeID& ID, const ImmutableSet& S) {
1039 ID.AddPointer(S.Root);
1042 inline void Profile(FoldingSetNodeID& ID) const {
1043 return Profile(ID,*this);
1046 //===--------------------------------------------------===//
1048 //===--------------------------------------------------===//
1050 void verify() const { if (Root) Root->verify(); }
1053 } // end namespace llvm