Chris Lattner | 57dbb3a | 2001-07-23 17:46:59 +0000 | [diff] [blame] | 1 | //===-- STLExtras.h - Useful functions when working with the STL -*- C++ -*--=// |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 2 | // |
| 3 | // This file contains some templates that are useful if you are working with the |
| 4 | // STL at all. |
| 5 | // |
| 6 | // No library is required when using these functinons. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | |
Chris Lattner | 57dbb3a | 2001-07-23 17:46:59 +0000 | [diff] [blame] | 10 | #ifndef LLVM_SUPPORT_STL_EXTRAS_H |
| 11 | #define LLVM_SUPPORT_STL_EXTRAS_H |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 12 | |
| 13 | #include <functional> |
| 14 | |
| 15 | //===----------------------------------------------------------------------===// |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 16 | // Extra additions to <functional> |
| 17 | //===----------------------------------------------------------------------===// |
| 18 | |
| 19 | // bind_obj - Often times you want to apply the member function of an object |
| 20 | // as a unary functor. This macro is shorthand that makes it happen less |
| 21 | // verbosely. |
| 22 | // |
| 23 | // Example: |
| 24 | // struct Summer { void accumulate(int x); } |
| 25 | // vector<int> Numbers; |
| 26 | // Summer MyS; |
| 27 | // for_each(Numbers.begin(), Numbers.end(), |
| 28 | // bind_obj(&MyS, &Summer::accumulate)); |
| 29 | // |
| 30 | // TODO: When I get lots of extra time, convert this from an evil macro |
| 31 | // |
| 32 | #define bind_obj(OBJ, METHOD) std::bind1st(std::mem_fun(METHOD), OBJ) |
| 33 | |
| 34 | |
| 35 | // bitwise_or - This is a simple functor that applys operator| on its two |
| 36 | // arguments to get a boolean result. |
| 37 | // |
| 38 | template<class Ty> |
Chris Lattner | 697954c | 2002-01-20 22:54:45 +0000 | [diff] [blame^] | 39 | struct bitwise_or : public std::binary_function<Ty, Ty, bool> { |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 40 | bool operator()(const Ty& left, const Ty& right) const { |
| 41 | return left | right; |
| 42 | } |
| 43 | }; |
| 44 | |
| 45 | |
Chris Lattner | 577b15f | 2001-07-02 01:09:41 +0000 | [diff] [blame] | 46 | // deleter - Very very very simple method that is used to invoke operator |
| 47 | // delete on something. It is used like this: |
| 48 | // |
| 49 | // for_each(V.begin(), B.end(), deleter<cfg::Interval>); |
| 50 | // |
| 51 | template <class T> |
| 52 | static inline void deleter(T *Ptr) { |
| 53 | delete Ptr; |
| 54 | } |
| 55 | |
| 56 | |
| 57 | |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 58 | //===----------------------------------------------------------------------===// |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 59 | // Extra additions to <iterator> |
| 60 | //===----------------------------------------------------------------------===// |
| 61 | |
| 62 | // mapped_iterator - This is a simple iterator adapter that causes a function to |
| 63 | // be dereferenced whenever operator* is invoked on the iterator. |
| 64 | // |
| 65 | // It turns out that this is disturbingly similar to boost::transform_iterator |
| 66 | // |
| 67 | #if 1 |
| 68 | template <class RootIt, class UnaryFunc> |
| 69 | class mapped_iterator { |
| 70 | RootIt current; |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 71 | UnaryFunc Fn; |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 72 | public: |
Chris Lattner | 697954c | 2002-01-20 22:54:45 +0000 | [diff] [blame^] | 73 | typedef typename std::iterator_traits<RootIt>::iterator_category |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 74 | iterator_category; |
Chris Lattner | 697954c | 2002-01-20 22:54:45 +0000 | [diff] [blame^] | 75 | typedef typename std::iterator_traits<RootIt>::difference_type |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 76 | difference_type; |
| 77 | typedef typename UnaryFunc::result_type value_type; |
| 78 | typedef typename UnaryFunc::result_type *pointer; |
| 79 | typedef void reference; // Can't modify value returned by fn |
| 80 | |
| 81 | typedef RootIt iterator_type; |
| 82 | typedef mapped_iterator<RootIt, UnaryFunc> _Self; |
| 83 | |
| 84 | inline RootIt &getCurrent() const { return current; } |
| 85 | |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 86 | inline explicit mapped_iterator(const RootIt &I, UnaryFunc F) |
| 87 | : current(I), Fn(F) {} |
| 88 | inline mapped_iterator(const mapped_iterator &It) |
| 89 | : current(It.current), Fn(It.Fn) {} |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 90 | |
| 91 | inline value_type operator*() const { // All this work to do this |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 92 | return Fn(*current); // little change |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 93 | } |
| 94 | |
| 95 | _Self& operator++() { ++current; return *this; } |
| 96 | _Self& operator--() { --current; return *this; } |
| 97 | _Self operator++(int) { _Self __tmp = *this; ++current; return __tmp; } |
| 98 | _Self operator--(int) { _Self __tmp = *this; --current; return __tmp; } |
| 99 | _Self operator+ (difference_type n) const { return _Self(current + n); } |
| 100 | _Self& operator+= (difference_type n) { current += n; return *this; } |
| 101 | _Self operator- (difference_type n) const { return _Self(current - n); } |
| 102 | _Self& operator-= (difference_type n) { current -= n; return *this; } |
| 103 | reference operator[](difference_type n) const { return *(*this + n); } |
| 104 | |
Chris Lattner | 697954c | 2002-01-20 22:54:45 +0000 | [diff] [blame^] | 105 | inline bool operator!=(const _Self &X) const { return !operator==(X); } |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 106 | inline bool operator==(const _Self &X) const { return current == X.current; } |
| 107 | inline bool operator< (const _Self &X) const { return current < X.current; } |
| 108 | |
| 109 | inline difference_type operator-(const _Self &X) const { |
| 110 | return current - X.current; |
| 111 | } |
| 112 | }; |
| 113 | |
| 114 | template <class _Iterator, class Func> |
| 115 | inline mapped_iterator<_Iterator, Func> |
| 116 | operator+(typename mapped_iterator<_Iterator, Func>::difference_type N, |
| 117 | const mapped_iterator<_Iterator, Func>& X) { |
| 118 | return mapped_iterator<_Iterator, Func>(X.getCurrent() - N); |
| 119 | } |
| 120 | |
| 121 | #else |
| 122 | |
| 123 | // This fails to work, because some iterators are not classes, for example |
| 124 | // vector iterators are commonly value_type **'s |
| 125 | template <class RootIt, class UnaryFunc> |
| 126 | class mapped_iterator : public RootIt { |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 127 | UnaryFunc Fn; |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 128 | public: |
| 129 | typedef typename UnaryFunc::result_type value_type; |
| 130 | typedef typename UnaryFunc::result_type *pointer; |
| 131 | typedef void reference; // Can't modify value returned by fn |
| 132 | |
| 133 | typedef mapped_iterator<RootIt, UnaryFunc> _Self; |
| 134 | typedef RootIt super; |
| 135 | inline explicit mapped_iterator(const RootIt &I) : super(I) {} |
| 136 | inline mapped_iterator(const super &It) : super(It) {} |
| 137 | |
| 138 | inline value_type operator*() const { // All this work to do |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 139 | return Fn(super::operator*()); // this little thing |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 140 | } |
| 141 | }; |
| 142 | #endif |
| 143 | |
| 144 | // map_iterator - Provide a convenient way to create mapped_iterators, just like |
| 145 | // make_pair is useful for creating pairs... |
| 146 | // |
| 147 | template <class ItTy, class FuncTy> |
| 148 | inline mapped_iterator<ItTy, FuncTy> map_iterator(const ItTy &I, FuncTy F) { |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 149 | return mapped_iterator<ItTy, FuncTy>(I, F); |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 150 | } |
| 151 | |
| 152 | |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 153 | //===----------------------------------------------------------------------===// |
| 154 | // Extra additions to <algorithm> |
| 155 | //===----------------------------------------------------------------------===// |
| 156 | |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 157 | // apply_until - Apply a functor to a sequence continually, unless the |
| 158 | // functor returns true. Return true if the functor returned true, return false |
| 159 | // if the functor never returned true. |
| 160 | // |
| 161 | template <class InputIt, class Function> |
| 162 | bool apply_until(InputIt First, InputIt Last, Function Func) { |
| 163 | for ( ; First != Last; ++First) |
| 164 | if (Func(*First)) return true; |
| 165 | return false; |
| 166 | } |
| 167 | |
| 168 | |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 169 | // reduce - Reduce a sequence values into a single value, given an initial |
| 170 | // value and an operator. |
| 171 | // |
| 172 | template <class InputIt, class Function, class ValueType> |
| 173 | ValueType reduce(InputIt First, InputIt Last, Function Func, ValueType Value) { |
| 174 | for ( ; First != Last; ++First) |
| 175 | Value = Func(*First, Value); |
| 176 | return Value; |
| 177 | } |
| 178 | |
| 179 | #if 1 // This is likely to be more efficient |
| 180 | |
| 181 | // reduce_apply - Reduce the result of applying a function to each value in a |
| 182 | // sequence, given an initial value, an operator, a function, and a sequence. |
| 183 | // |
| 184 | template <class InputIt, class Function, class ValueType, class TransFunc> |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 185 | inline ValueType reduce_apply(InputIt First, InputIt Last, Function Func, |
| 186 | ValueType Value, TransFunc XForm) { |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 187 | for ( ; First != Last; ++First) |
| 188 | Value = Func(XForm(*First), Value); |
| 189 | return Value; |
| 190 | } |
| 191 | |
| 192 | #else // This is arguably more elegant |
| 193 | |
| 194 | // reduce_apply - Reduce the result of applying a function to each value in a |
| 195 | // sequence, given an initial value, an operator, a function, and a sequence. |
| 196 | // |
| 197 | template <class InputIt, class Function, class ValueType, class TransFunc> |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 198 | inline ValueType reduce_apply2(InputIt First, InputIt Last, Function Func, |
| 199 | ValueType Value, TransFunc XForm) { |
| 200 | return reduce(map_iterator(First, XForm), map_iterator(Last, XForm), |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 201 | Func, Value); |
| 202 | } |
| 203 | #endif |
| 204 | |
| 205 | |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 206 | // reduce_apply_bool - Reduce the result of applying a (bool returning) function |
| 207 | // to each value in a sequence. All of the bools returned by the mapped |
| 208 | // function are bitwise or'd together, and the result is returned. |
Chris Lattner | 3704c8c | 2001-06-25 03:54:32 +0000 | [diff] [blame] | 209 | // |
Chris Lattner | 42e018c | 2001-06-27 23:32:12 +0000 | [diff] [blame] | 210 | template <class InputIt, class Function> |
| 211 | inline bool reduce_apply_bool(InputIt First, InputIt Last, Function Func) { |
| 212 | return reduce_apply(First, Last, bitwise_or<bool>(), false, Func); |
| 213 | } |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 214 | |
Chris Lattner | 643afb3 | 2001-09-07 16:30:28 +0000 | [diff] [blame] | 215 | |
| 216 | // map - This function maps the specified input sequence into the specified |
| 217 | // output iterator, applying a unary function in between. |
| 218 | // |
| 219 | template <class InIt, class OutIt, class Functor> |
| 220 | inline OutIt mapto(InIt Begin, InIt End, OutIt Dest, Functor F) { |
| 221 | return copy(map_iterator(Begin, F), map_iterator(End, F), Dest); |
| 222 | } |
Chris Lattner | 18d64ed | 2001-06-21 05:25:51 +0000 | [diff] [blame] | 223 | #endif |