llvm-6502/include/llvm/ADT/ImmutableSet.h
Ted Kremenek 52e2d83e65 Changed the return type of type-specific Allocate() methods to return
void*.  This is hint that we are returning uninitialized memory rather
than a constructed object.

Patched ImutAVLTree to conform to this new interface.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43106 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-18 00:30:14 +00:00

923 lines
30 KiB
C++

//===--- ImmutableSet.h - Immutable (functional) set interface --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Ted Kremenek and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ImutAVLTree and ImmutableSet classes.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_IMSET_H
#define LLVM_ADT_IMSET_H
#include "llvm/Support/Allocator.h"
#include "llvm/ADT/FoldingSet.h"
#include <cassert>
namespace llvm {
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Definition.
//===----------------------------------------------------------------------===//
template <typename ImutInfo> class ImutAVLFactory;
template <typename ImutInfo> class ImutAVLTreeInOrderIterator;
template <typename ImutInfo >
class ImutAVLTree : public FoldingSetNode {
public:
typedef typename ImutInfo::key_type_ref key_type_ref;
typedef typename ImutInfo::value_type value_type;
typedef typename ImutInfo::value_type_ref value_type_ref;
typedef ImutAVLFactory<ImutInfo> Factory;
friend class ImutAVLFactory<ImutInfo>;
typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator;
//===----------------------------------------------------===//
// Public Interface.
//===----------------------------------------------------===//
/// getLeft - Returns a pointer to the left subtree. This value
/// is NULL if there is no left subtree.
ImutAVLTree* getLeft() const {
assert (!isMutable() && "Node is incorrectly marked mutable.");
return reinterpret_cast<ImutAVLTree*>(Left);
}
/// getRight - Returns a pointer to the right subtree. This value is
/// NULL if there is no right subtree.
ImutAVLTree* getRight() const { return Right; }
/// getHeight - Returns the height of the tree. A tree with no subtrees
/// has a height of 1.
unsigned getHeight() const { return Height; }
/// getValue - Returns the data value associated with the tree node.
const value_type& getValue() const { return Value; }
/// find - Finds the subtree associated with the specified key value.
/// This method returns NULL if no matching subtree is found.
ImutAVLTree* find(key_type_ref K) {
ImutAVLTree *T = this;
while (T) {
key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue());
if (ImutInfo::isEqual(K,CurrentKey))
return T;
else if (ImutInfo::isLess(K,CurrentKey))
T = T->getLeft();
else
T = T->getRight();
}
return NULL;
}
/// size - Returns the number of nodes in the tree, which includes
/// both leaves and non-leaf nodes.
unsigned size() const {
unsigned n = 1;
if (const ImutAVLTree* L = getLeft()) n += L->size();
if (const ImutAVLTree* R = getRight()) n += R->size();
return n;
}
/// begin - Returns an iterator that iterates over the nodes of the tree
/// in an inorder traversal. The returned iterator thus refers to the
/// the tree node with the minimum data element.
iterator begin() const { return iterator(this); }
/// end - Returns an iterator for the tree that denotes the end of an
/// inorder traversal.
iterator end() const { return iterator(); }
/// isEqual - Compares two trees for structural equality and returns true
/// if they are equal. This worst case performance of this operation is
// linear in the sizes of the trees.
bool isEqual(const ImutAVLTree& RHS) const {
if (&RHS == this)
return true;
iterator LItr = begin(), LEnd = end();
iterator RItr = RHS.begin(), REnd = RHS.end();
while (LItr != LEnd && RItr != REnd) {
if (*LItr == *RItr) {
LItr.SkipSubTree();
RItr.SkipSubTree();
continue;
}
// FIXME: need to compare data values, not key values, but our
// traits don't support this yet.
if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(LItr->getValue()),
ImutInfo::KeyOfValue(RItr->getValue())))
return false;
++LItr;
++RItr;
}
return LItr == LEnd && RItr == REnd;
}
/// isNotEqual - Compares two trees for structural inequality. Performance
/// is the same is isEqual.
bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); }
/// contains - Returns true if this tree contains a subtree (node) that
/// has an data element that matches the specified key. Complexity
/// is logarithmic in the size of the tree.
bool contains(const key_type_ref K) { return (bool) find(K); }
/// foreach - A member template the accepts invokes operator() on a functor
/// object (specifed by Callback) for every node/subtree in the tree.
/// Nodes are visited using an inorder traversal.
template <typename Callback>
void foreach(Callback& C) {
if (ImutAVLTree* L = getLeft()) L->foreach(C);
C(Value);
if (ImutAVLTree* R = getRight()) R->foreach(C);
}
/// verify - A utility method that checks that the balancing and
/// ordering invariants of the tree are satisifed. It is a recursive
/// method that returns the height of the tree, which is then consumed
/// by the enclosing verify call. External callers should ignore the
/// return value. An invalid tree will cause an assertion to fire in
/// a debug build.
unsigned verify() const {
unsigned HL = getLeft() ? getLeft()->verify() : 0;
unsigned HR = getRight() ? getRight()->verify() : 0;
assert (getHeight() == ( HL > HR ? HL : HR ) + 1
&& "Height calculation wrong.");
assert ((HL > HR ? HL-HR : HR-HL) <= 2
&& "Balancing invariant violated.");
assert (!getLeft()
|| ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()),
ImutInfo::KeyOfValue(getValue()))
&& "Value in left child is not less that current value.");
assert (!getRight()
|| ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()),
ImutInfo::KeyOfValue(getRight()->getValue()))
&& "Current value is not less that value of right child.");
return getHeight();
}
//===----------------------------------------------------===//
// Internal Values.
//===----------------------------------------------------===//
private:
uintptr_t Left;
ImutAVLTree* Right;
unsigned Height;
value_type Value;
//===----------------------------------------------------===//
// Profiling or FoldingSet.
//===----------------------------------------------------===//
private:
/// Profile - Generates a FoldingSet profile for a tree node before it is
/// created. This is used by the ImutAVLFactory when creating
/// trees.
static inline
void Profile(FoldingSetNodeID& ID, ImutAVLTree* L, ImutAVLTree* R,
value_type_ref V) {
ID.AddPointer(L);
ID.AddPointer(R);
ImutInfo::Profile(ID,V);
}
public:
/// Profile - Generates a FoldingSet profile for an existing tree node.
void Profile(FoldingSetNodeID& ID) {
Profile(ID,getSafeLeft(),getRight(),getValue());
}
//===----------------------------------------------------===//
// Internal methods (node manipulation; used by Factory).
//===----------------------------------------------------===//
private:
enum { Mutable = 0x1 };
/// ImutAVLTree - Internal constructor that is only called by
/// ImutAVLFactory.
ImutAVLTree(ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, unsigned height)
: Left(reinterpret_cast<uintptr_t>(l) | Mutable),
Right(r), Height(height), Value(v) {}
/// isMutable - Returns true if the left and right subtree references
/// (as well as height) can be changed. If this method returns false,
/// the tree is truly immutable. Trees returned from an ImutAVLFactory
/// object should always have this method return true. Further, if this
/// method returns false for an instance of ImutAVLTree, all subtrees
/// will also have this method return false. The converse is not true.
bool isMutable() const { return Left & Mutable; }
/// getSafeLeft - Returns the pointer to the left tree by always masking
/// out the mutable bit. This is used internally by ImutAVLFactory,
/// as no trees returned to the client should have the mutable flag set.
ImutAVLTree* getSafeLeft() const {
return reinterpret_cast<ImutAVLTree*>(Left & ~Mutable);
}
//===----------------------------------------------------===//
// Mutating operations. A tree root can be manipulated as
// long as its reference has not "escaped" from internal
// methods of a factory object (see below). When a tree
// pointer is externally viewable by client code, the
// internal "mutable bit" is cleared to mark the tree
// immutable. Note that a tree that still has its mutable
// bit set may have children (subtrees) that are themselves
// immutable.
//===----------------------------------------------------===//
/// MarkImmutable - Clears the mutable flag for a tree. After this happens,
/// it is an error to call setLeft(), setRight(), and setHeight(). It
/// is also then safe to call getLeft() instead of getSafeLeft().
void MarkImmutable() {
assert (isMutable() && "Mutable flag already removed.");
Left &= ~Mutable;
}
/// setLeft - Changes the reference of the left subtree. Used internally
/// by ImutAVLFactory.
void setLeft(ImutAVLTree* NewLeft) {
assert (isMutable() &&
"Only a mutable tree can have its left subtree changed.");
Left = reinterpret_cast<uintptr_t>(NewLeft) | Mutable;
}
/// setRight - Changes the reference of the right subtree. Used internally
/// by ImutAVLFactory.
void setRight(ImutAVLTree* NewRight) {
assert (isMutable() &&
"Only a mutable tree can have its right subtree changed.");
Right = NewRight;
}
/// setHeight - Changes the height of the tree. Used internally by
/// ImutAVLFactory.
void setHeight(unsigned h) {
assert (isMutable() && "Only a mutable tree can have its height changed.");
Height = h;
}
};
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Factory class.
//===----------------------------------------------------------------------===//
template <typename ImutInfo >
class ImutAVLFactory {
typedef ImutAVLTree<ImutInfo> TreeTy;
typedef typename TreeTy::value_type_ref value_type_ref;
typedef typename TreeTy::key_type_ref key_type_ref;
typedef FoldingSet<TreeTy> CacheTy;
CacheTy Cache;
BumpPtrAllocator Allocator;
//===--------------------------------------------------===//
// Public interface.
//===--------------------------------------------------===//
public:
ImutAVLFactory() {}
TreeTy* Add(TreeTy* T, value_type_ref V) {
T = Add_internal(V,T);
MarkImmutable(T);
return T;
}
TreeTy* Remove(TreeTy* T, key_type_ref V) {
T = Remove_internal(V,T);
MarkImmutable(T);
return T;
}
TreeTy* GetEmptyTree() const { return NULL; }
BumpPtrAllocator& getAllocator() { return Allocator; }
//===--------------------------------------------------===//
// A bunch of quick helper functions used for reasoning
// about the properties of trees and their children.
// These have succinct names so that the balancing code
// is as terse (and readable) as possible.
//===--------------------------------------------------===//
private:
bool isEmpty(TreeTy* T) const { return !T; }
unsigned Height(TreeTy* T) const { return T ? T->getHeight() : 0; }
TreeTy* Left(TreeTy* T) const { return T->getSafeLeft(); }
TreeTy* Right(TreeTy* T) const { return T->getRight(); }
value_type_ref Value(TreeTy* T) const { return T->Value; }
unsigned IncrementHeight(TreeTy* L, TreeTy* R) const {
unsigned hl = Height(L);
unsigned hr = Height(R);
return ( hl > hr ? hl : hr ) + 1;
}
//===--------------------------------------------------===//
// "CreateNode" is used to generate new tree roots that link
// to other trees. The functon may also simply move links
// in an existing root if that root is still marked mutable.
// This is necessary because otherwise our balancing code
// would leak memory as it would create nodes that are
// then discarded later before the finished tree is
// returned to the caller.
//===--------------------------------------------------===//
TreeTy* CreateNode(TreeTy* L, value_type_ref V, TreeTy* R) {
FoldingSetNodeID ID;
TreeTy::Profile(ID,L,R,V);
void* InsertPos;
if (TreeTy* T = Cache.FindNodeOrInsertPos(ID,InsertPos))
return T;
assert (InsertPos != NULL);
// Allocate the new tree node and insert it into the cache.
TreeTy* T = (TreeTy*) Allocator.Allocate<TreeTy>();
new (T) TreeTy(L,R,V,IncrementHeight(L,R));
Cache.InsertNode(T,InsertPos);
return T;
}
TreeTy* CreateNode(TreeTy* L, TreeTy* OldTree, TreeTy* R) {
assert (!isEmpty(OldTree));
if (OldTree->isMutable()) {
OldTree->setLeft(L);
OldTree->setRight(R);
OldTree->setHeight(IncrementHeight(L,R));
return OldTree;
}
else return CreateNode(L, Value(OldTree), R);
}
/// Balance - Used by Add_internal and Remove_internal to
/// balance a newly created tree.
TreeTy* Balance(TreeTy* L, value_type_ref V, TreeTy* R) {
unsigned hl = Height(L);
unsigned hr = Height(R);
if (hl > hr + 2) {
assert (!isEmpty(L) &&
"Left tree cannot be empty to have a height >= 2.");
TreeTy* LL = Left(L);
TreeTy* LR = Right(L);
if (Height(LL) >= Height(LR))
return CreateNode(LL, L, CreateNode(LR,V,R));
assert (!isEmpty(LR) &&
"LR cannot be empty because it has a height >= 1.");
TreeTy* LRL = Left(LR);
TreeTy* LRR = Right(LR);
return CreateNode(CreateNode(LL,L,LRL), LR, CreateNode(LRR,V,R));
}
else if (hr > hl + 2) {
assert (!isEmpty(R) &&
"Right tree cannot be empty to have a height >= 2.");
TreeTy* RL = Left(R);
TreeTy* RR = Right(R);
if (Height(RR) >= Height(RL))
return CreateNode(CreateNode(L,V,RL), R, RR);
assert (!isEmpty(RL) &&
"RL cannot be empty because it has a height >= 1.");
TreeTy* RLL = Left(RL);
TreeTy* RLR = Right(RL);
return CreateNode(CreateNode(L,V,RLL), RL, CreateNode(RLR,R,RR));
}
else
return CreateNode(L,V,R);
}
/// Add_internal - Creates a new tree that includes the specified
/// data and the data from the original tree. If the original tree
/// already contained the data item, the original tree is returned.
TreeTy* Add_internal(value_type_ref V, TreeTy* T) {
if (isEmpty(T))
return CreateNode(T, V, T);
assert (!T->isMutable());
key_type_ref K = ImutInfo::KeyOfValue(V);
key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
if (ImutInfo::isEqual(K,KCurrent))
return CreateNode(Left(T), V, Right(T));
else if (ImutInfo::isLess(K,KCurrent))
return Balance(Add_internal(V,Left(T)), Value(T), Right(T));
else
return Balance(Left(T), Value(T), Add_internal(V,Right(T)));
}
/// Remove_interal - Creates a new tree that includes all the data
/// from the original tree except the specified data. If the
/// specified data did not exist in the original tree, the original
/// tree is returned.
TreeTy* Remove_internal(key_type_ref K, TreeTy* T) {
if (isEmpty(T))
return T;
assert (!T->isMutable());
key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
if (ImutInfo::isEqual(K,KCurrent))
return CombineLeftRightTrees(Left(T),Right(T));
else if (ImutInfo::isLess(K,KCurrent))
return Balance(Remove_internal(K,Left(T)), Value(T), Right(T));
else
return Balance(Left(T), Value(T), Remove_internal(K,Right(T)));
}
TreeTy* CombineLeftRightTrees(TreeTy* L, TreeTy* R) {
if (isEmpty(L)) return R;
if (isEmpty(R)) return L;
TreeTy* OldNode;
TreeTy* NewRight = RemoveMinBinding(R,OldNode);
return Balance(L,Value(OldNode),NewRight);
}
TreeTy* RemoveMinBinding(TreeTy* T, TreeTy*& NodeRemoved) {
assert (!isEmpty(T));
if (isEmpty(Left(T))) {
NodeRemoved = T;
return Right(T);
}
return Balance(RemoveMinBinding(Left(T),NodeRemoved),Value(T),Right(T));
}
/// MarkImmutable - Clears the mutable bits of a root and all of its
/// descendants.
void MarkImmutable(TreeTy* T) {
if (!T || !T->isMutable())
return;
T->MarkImmutable();
MarkImmutable(Left(T));
MarkImmutable(Right(T));
}
};
//===----------------------------------------------------------------------===//
// Immutable AVL-Tree Iterators.
//===----------------------------------------------------------------------===//
template <typename ImutInfo>
class ImutAVLTreeGenericIterator {
SmallVector<uintptr_t,20> stack;
public:
enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3,
Flags=0x3 };
typedef ImutAVLTree<ImutInfo> TreeTy;
typedef ImutAVLTreeGenericIterator<ImutInfo> _Self;
inline ImutAVLTreeGenericIterator() {}
inline ImutAVLTreeGenericIterator(const TreeTy* Root) {
if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root));
}
TreeTy* operator*() const {
assert (!stack.empty());
return reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
}
uintptr_t getVisitState() {
assert (!stack.empty());
return stack.back() & Flags;
}
bool AtEnd() const { return stack.empty(); }
bool AtBeginning() const {
return stack.size() == 1 && getVisitState() == VisitedNone;
}
void SkipToParent() {
assert (!stack.empty());
stack.pop_back();
if (stack.empty())
return;
switch (getVisitState()) {
case VisitedNone:
stack.back() |= VisitedLeft;
break;
case VisitedLeft:
stack.back() |= VisitedRight;
break;
default:
assert (false && "Unreachable.");
}
}
inline bool operator==(const _Self& x) const {
if (stack.size() != x.stack.size())
return false;
for (unsigned i = 0 ; i < stack.size(); i++)
if (stack[i] != x.stack[i])
return false;
return true;
}
inline bool operator!=(const _Self& x) const { return !operator==(x); }
_Self& operator++() {
assert (!stack.empty());
TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
assert (Current);
switch (getVisitState()) {
case VisitedNone:
if (TreeTy* L = Current->getLeft())
stack.push_back(reinterpret_cast<uintptr_t>(L));
else
stack.back() |= VisitedLeft;
break;
case VisitedLeft:
if (TreeTy* R = Current->getRight())
stack.push_back(reinterpret_cast<uintptr_t>(R));
else
stack.back() |= VisitedRight;
break;
case VisitedRight:
SkipToParent();
break;
default:
assert (false && "Unreachable.");
}
return *this;
}
_Self& operator--() {
assert (!stack.empty());
TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
assert (Current);
switch (getVisitState()) {
case VisitedNone:
stack.pop_back();
break;
case VisitedLeft:
stack.back() &= ~Flags; // Set state to "VisitedNone."
if (TreeTy* L = Current->getLeft())
stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight);
break;
case VisitedRight:
stack.back() &= ~Flags;
stack.back() |= VisitedLeft;
if (TreeTy* R = Current->getRight())
stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight);
break;
default:
assert (false && "Unreachable.");
}
return *this;
}
};
template <typename ImutInfo>
class ImutAVLTreeInOrderIterator {
typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy;
InternalIteratorTy InternalItr;
public:
typedef ImutAVLTree<ImutInfo> TreeTy;
typedef ImutAVLTreeInOrderIterator<ImutInfo> _Self;
ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) {
if (Root) operator++(); // Advance to first element.
}
ImutAVLTreeInOrderIterator() : InternalItr() {}
inline bool operator==(const _Self& x) const {
return InternalItr == x.InternalItr;
}
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline TreeTy* operator*() const { return *InternalItr; }
inline TreeTy* operator->() const { return *InternalItr; }
inline _Self& operator++() {
do ++InternalItr;
while (!InternalItr.AtEnd() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
return *this;
}
inline _Self& operator--() {
do --InternalItr;
while (!InternalItr.AtBeginning() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
return *this;
}
inline void SkipSubTree() {
InternalItr.SkipToParent();
while (!InternalItr.AtEnd() &&
InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft)
++InternalItr;
}
};
//===----------------------------------------------------------------------===//
// Trait classes for Profile information.
//===----------------------------------------------------------------------===//
/// Generic profile template. The default behavior is to invoke the
/// profile method of an object. Specializations for primitive integers
/// and generic handling of pointers is done below.
template <typename T>
struct ImutProfileInfo {
typedef const T value_type;
typedef const T& value_type_ref;
static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
X.Profile(ID);
}
};
/// Profile traits for integers.
template <typename T>
struct ImutProfileInteger {
typedef const T value_type;
typedef const T& value_type_ref;
static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
ID.AddInteger(X);
}
};
#define PROFILE_INTEGER_INFO(X)\
template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {};
PROFILE_INTEGER_INFO(char)
PROFILE_INTEGER_INFO(unsigned char)
PROFILE_INTEGER_INFO(short)
PROFILE_INTEGER_INFO(unsigned short)
PROFILE_INTEGER_INFO(unsigned)
PROFILE_INTEGER_INFO(signed)
PROFILE_INTEGER_INFO(long)
PROFILE_INTEGER_INFO(unsigned long)
PROFILE_INTEGER_INFO(long long)
PROFILE_INTEGER_INFO(unsigned long long)
#undef PROFILE_INTEGER_INFO
/// Generic profile trait for pointer types. We treat pointers as
/// references to unique objects.
template <typename T>
struct ImutProfileInfo<T*> {
typedef const T* value_type;
typedef value_type value_type_ref;
static inline void Profile(FoldingSetNodeID &ID, value_type_ref X) {
ID.AddPointer(X);
}
};
//===----------------------------------------------------------------------===//
// Trait classes that contain element comparison operators and type
// definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These
// inherit from the profile traits (ImutProfileInfo) to include operations
// for element profiling.
//===----------------------------------------------------------------------===//
/// ImutContainerInfo - Generic definition of comparison operations for
/// elements of immutable containers that defaults to using
/// std::equal_to<> and std::less<> to perform comparison of elements.
template <typename T>
struct ImutContainerInfo : public ImutProfileInfo<T> {
typedef typename ImutProfileInfo<T>::value_type value_type;
typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref;
typedef value_type key_type;
typedef value_type_ref key_type_ref;
static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
return std::equal_to<key_type>()(LHS,RHS);
}
static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
return std::less<key_type>()(LHS,RHS);
}
};
/// ImutContainerInfo - Specialization for pointer values to treat pointers
/// as references to unique objects. Pointers are thus compared by
/// their addresses.
template <typename T>
struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> {
typedef typename ImutProfileInfo<T*>::value_type value_type;
typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref;
typedef value_type key_type;
typedef value_type_ref key_type_ref;
static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
return LHS == RHS;
}
static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
return LHS < RHS;
}
};
//===----------------------------------------------------------------------===//
// Immutable Set
//===----------------------------------------------------------------------===//
template <typename ValT, typename ValInfo = ImutContainerInfo<ValT> >
class ImmutableSet {
public:
typedef typename ValInfo::value_type value_type;
typedef typename ValInfo::value_type_ref value_type_ref;
private:
typedef ImutAVLTree<ValInfo> TreeTy;
TreeTy* Root;
ImmutableSet(TreeTy* R) : Root(R) {}
public:
class Factory {
typename TreeTy::Factory F;
public:
Factory() {}
/// GetEmptySet - Returns an immutable set that contains no elements.
ImmutableSet GetEmptySet() { return ImmutableSet(F.GetEmptyTree()); }
/// Add - Creates a new immutable set that contains all of the values
/// of the original set with the addition of the specified value. If
/// the original set already included the value, then the original set is
/// returned and no memory is allocated. The time and space complexity
/// of this operation is logarithmic in the size of the original set.
/// The memory allocated to represent the set is released when the
/// factory object that created the set is destroyed.
ImmutableSet Add(ImmutableSet Old, value_type_ref V) {
return ImmutableSet(F.Add(Old.Root,V));
}
/// Remove - Creates a new immutable set that contains all of the values
/// of the original set with the exception of the specified value. If
/// the original set did not contain the value, the original set is
/// returned and no memory is allocated. The time and space complexity
/// of this operation is logarithmic in the size of the original set.
/// The memory allocated to represent the set is released when the
/// factory object that created the set is destroyed.
ImmutableSet Remove(ImmutableSet Old, value_type_ref V) {
return ImmutableSet(F.Remove(Old.Root,V));
}
BumpPtrAllocator& getAllocator() { return F.getAllocator(); }
private:
Factory(const Factory& RHS) {};
void operator=(const Factory& RHS) {};
};
friend class Factory;
/// contains - Returns true if the set contains the specified value.
bool contains(const value_type_ref V) const {
return Root ? Root->contains(V) : false;
}
bool operator==(ImmutableSet RHS) const {
return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
}
bool operator!=(ImmutableSet RHS) const {
return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
}
/// isEmpty - Return true if the set contains no elements.
bool isEmpty() const { return !Root; }
template <typename Callback>
void foreach(Callback& C) { if (Root) Root->foreach(C); }
template <typename Callback>
void foreach() { if (Root) { Callback C; Root->foreach(C); } }
//===--------------------------------------------------===//
// Iterators.
//===--------------------------------------------------===//
class iterator {
typename TreeTy::iterator itr;
iterator() {}
iterator(TreeTy* t) : itr(t) {}
friend class ImmutableSet<ValT,ValInfo>;
public:
inline value_type_ref operator*() const { return itr->getValue(); }
inline iterator& operator++() { ++itr; return *this; }
inline iterator operator++(int) { iterator tmp(*this); ++itr; return tmp; }
inline iterator& operator--() { --itr; return *this; }
inline iterator operator--(int) { iterator tmp(*this); --itr; return tmp; }
inline bool operator==(const iterator& RHS) const { return RHS.itr == itr; }
inline bool operator!=(const iterator& RHS) const { return RHS.itr != itr; }
};
iterator begin() const { return iterator(Root); }
iterator end() const { return iterator(); }
//===--------------------------------------------------===//
// For testing.
//===--------------------------------------------------===//
void verify() const { if (Root) Root->verify(); }
unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
};
} // end namespace llvm
#endif