Tue, 28 Mar 2023 21:00:33 +0200
allow NULL for allocator and comparator
universe@494 | 1 | /* |
universe@494 | 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. |
universe@494 | 3 | * |
universe@494 | 4 | * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved. |
universe@494 | 5 | * |
universe@494 | 6 | * Redistribution and use in source and binary forms, with or without |
universe@494 | 7 | * modification, are permitted provided that the following conditions are met: |
universe@494 | 8 | * |
universe@494 | 9 | * 1. Redistributions of source code must retain the above copyright |
universe@494 | 10 | * notice, this list of conditions and the following disclaimer. |
universe@494 | 11 | * |
universe@494 | 12 | * 2. Redistributions in binary form must reproduce the above copyright |
universe@494 | 13 | * notice, this list of conditions and the following disclaimer in the |
universe@494 | 14 | * documentation and/or other materials provided with the distribution. |
universe@494 | 15 | * |
universe@494 | 16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
universe@494 | 17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
universe@494 | 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
universe@494 | 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
universe@494 | 20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
universe@494 | 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
universe@494 | 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
universe@494 | 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
universe@494 | 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
universe@494 | 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
universe@494 | 26 | * POSSIBILITY OF SUCH DAMAGE. |
universe@494 | 27 | */ |
universe@494 | 28 | /** |
universe@494 | 29 | * \file iterator.h |
universe@494 | 30 | * \brief Interface for iterator implementations. |
universe@494 | 31 | * \author Mike Becker |
universe@494 | 32 | * \author Olaf Wintermann |
universe@494 | 33 | * \version 3.0 |
universe@494 | 34 | * \copyright 2-Clause BSD License |
universe@494 | 35 | */ |
universe@494 | 36 | |
universe@494 | 37 | #ifndef UCX_ITERATOR_H |
universe@494 | 38 | #define UCX_ITERATOR_H |
universe@494 | 39 | |
universe@494 | 40 | #include "common.h" |
universe@494 | 41 | |
universe@494 | 42 | /** |
universe@630 | 43 | * The base of mutating and non-mutating iterators. |
universe@494 | 44 | */ |
universe@630 | 45 | struct cx_iterator_base_s { |
universe@494 | 46 | /** |
universe@494 | 47 | * True iff the iterator points to valid data. |
universe@494 | 48 | */ |
universe@551 | 49 | __attribute__ ((__nonnull__)) |
universe@630 | 50 | bool (*valid)(void const *); |
universe@494 | 51 | |
universe@494 | 52 | /** |
universe@494 | 53 | * Returns a pointer to the current element. |
universe@494 | 54 | */ |
universe@551 | 55 | __attribute__ ((__nonnull__)) |
universe@630 | 56 | void *(*current)(void const *); |
universe@494 | 57 | |
universe@494 | 58 | /** |
universe@641 | 59 | * Original implementation in case the function needs to be wrapped. |
universe@641 | 60 | */ |
universe@641 | 61 | __attribute__ ((__nonnull__)) |
universe@641 | 62 | void *(*current_impl)(void const *); |
universe@641 | 63 | |
universe@641 | 64 | /** |
universe@494 | 65 | * Advances the iterator. |
universe@494 | 66 | */ |
universe@551 | 67 | __attribute__ ((__nonnull__)) |
universe@630 | 68 | void (*next)(void *); |
universe@630 | 69 | |
universe@630 | 70 | /** |
universe@630 | 71 | * Flag current element for removal, if possible. |
universe@630 | 72 | */ |
universe@630 | 73 | __attribute__ ((__nonnull__)) |
universe@630 | 74 | bool (*flag_removal)(void *); |
universe@630 | 75 | |
universe@630 | 76 | /** |
universe@630 | 77 | * Indicates whether this iterator is muting. |
universe@630 | 78 | */ |
universe@630 | 79 | bool mutating; |
universe@630 | 80 | |
universe@630 | 81 | /** |
universe@630 | 82 | * Internal flag for removing the current element when advancing. |
universe@630 | 83 | */ |
universe@630 | 84 | bool remove; |
universe@630 | 85 | }; |
universe@630 | 86 | |
universe@630 | 87 | /** |
universe@630 | 88 | * Internal iterator struct - use CxMutIterator. |
universe@630 | 89 | */ |
universe@630 | 90 | struct cx_mut_iterator_s { |
universe@630 | 91 | |
universe@630 | 92 | /** |
universe@630 | 93 | * The base properties of this iterator. |
universe@630 | 94 | */ |
universe@630 | 95 | struct cx_iterator_base_s base; |
universe@495 | 96 | |
universe@495 | 97 | /** |
universe@495 | 98 | * Handle for the current element, if required. |
universe@495 | 99 | */ |
universe@495 | 100 | void *elem_handle; |
universe@495 | 101 | |
universe@495 | 102 | /** |
universe@495 | 103 | * Handle for the source collection, if any. |
universe@495 | 104 | */ |
universe@495 | 105 | void *src_handle; |
universe@495 | 106 | |
universe@495 | 107 | /** |
universe@551 | 108 | * Field for storing a key-value pair. |
universe@551 | 109 | * May be used by iterators that iterate over k/v-collections. |
universe@551 | 110 | */ |
universe@551 | 111 | struct { |
universe@551 | 112 | /** |
universe@551 | 113 | * A pointer to the key. |
universe@551 | 114 | */ |
universe@630 | 115 | void const *key; |
universe@551 | 116 | /** |
universe@551 | 117 | * A pointer to the value. |
universe@551 | 118 | */ |
universe@551 | 119 | void *value; |
universe@551 | 120 | } kv_data; |
universe@551 | 121 | |
universe@551 | 122 | /** |
universe@551 | 123 | * Field for storing a slot number. |
universe@551 | 124 | * May be used by iterators that iterate over multi-bucket collections. |
universe@551 | 125 | */ |
universe@551 | 126 | size_t slot; |
universe@551 | 127 | |
universe@551 | 128 | /** |
universe@495 | 129 | * If the iterator is position-aware, contains the index of the element in the underlying collection. |
universe@495 | 130 | * Otherwise, this field is usually uninitialized. |
universe@495 | 131 | */ |
universe@495 | 132 | size_t index; |
universe@630 | 133 | }; |
universe@630 | 134 | |
universe@630 | 135 | /** |
universe@630 | 136 | * Mutating iterator value type. |
universe@630 | 137 | * |
universe@630 | 138 | * An iterator points to a certain element in an (possibly unbounded) chain of elements. |
universe@630 | 139 | * Iterators that are based on collections (which have a defined "first" element), are supposed |
universe@630 | 140 | * to be "position-aware", which means that they keep track of the current index within the collection. |
universe@630 | 141 | * |
universe@630 | 142 | * @note Objects that are pointed to by an iterator are mutable through that iterator. However, if the |
universe@630 | 143 | * iterator is based on a collection and the underlying collection is mutated by other means than this iterator |
universe@630 | 144 | * (e.g. elements added or removed), the iterator becomes invalid (regardless of what cxIteratorValid() returns) |
universe@630 | 145 | * and MUST be re-obtained from the collection. |
universe@630 | 146 | * |
universe@630 | 147 | * @see CxIterator |
universe@630 | 148 | */ |
universe@630 | 149 | typedef struct cx_mut_iterator_s CxMutIterator; |
universe@630 | 150 | |
universe@630 | 151 | /** |
universe@630 | 152 | * Internal iterator struct - use CxIterator. |
universe@630 | 153 | */ |
universe@630 | 154 | struct cx_iterator_s { |
universe@495 | 155 | |
universe@495 | 156 | /** |
universe@630 | 157 | * The base properties of this iterator. |
universe@495 | 158 | */ |
universe@630 | 159 | struct cx_iterator_base_s base; |
universe@630 | 160 | |
universe@630 | 161 | /** |
universe@630 | 162 | * Handle for the current element, if required. |
universe@630 | 163 | */ |
universe@630 | 164 | void *elem_handle; |
universe@630 | 165 | |
universe@630 | 166 | /** |
universe@630 | 167 | * Handle for the source collection, if any. |
universe@630 | 168 | */ |
universe@630 | 169 | void const *src_handle; |
universe@630 | 170 | |
universe@630 | 171 | /** |
universe@630 | 172 | * Field for storing a key-value pair. |
universe@630 | 173 | * May be used by iterators that iterate over k/v-collections. |
universe@630 | 174 | */ |
universe@630 | 175 | struct { |
universe@630 | 176 | /** |
universe@630 | 177 | * A pointer to the key. |
universe@630 | 178 | */ |
universe@630 | 179 | void const *key; |
universe@630 | 180 | /** |
universe@630 | 181 | * A pointer to the value. |
universe@630 | 182 | */ |
universe@630 | 183 | void *value; |
universe@630 | 184 | } kv_data; |
universe@630 | 185 | |
universe@630 | 186 | /** |
universe@630 | 187 | * Field for storing a slot number. |
universe@630 | 188 | * May be used by iterators that iterate over multi-bucket collections. |
universe@630 | 189 | */ |
universe@630 | 190 | size_t slot; |
universe@630 | 191 | |
universe@630 | 192 | /** |
universe@630 | 193 | * If the iterator is position-aware, contains the index of the element in the underlying collection. |
universe@630 | 194 | * Otherwise, this field is usually uninitialized. |
universe@630 | 195 | */ |
universe@630 | 196 | size_t index; |
universe@494 | 197 | }; |
universe@494 | 198 | |
universe@494 | 199 | /** |
universe@500 | 200 | * Iterator value type. |
universe@500 | 201 | * An iterator points to a certain element in an (possibly unbounded) chain of elements. |
universe@500 | 202 | * Iterators that are based on collections (which have a defined "first" element), are supposed |
universe@500 | 203 | * to be "position-aware", which means that they keep track of the current index within the collection. |
universe@500 | 204 | * |
universe@630 | 205 | * @note Objects that are pointed to by an iterator are always mutable through that iterator. However, |
universe@630 | 206 | * this iterator cannot mutate the collection itself (add or remove elements) and any mutation of the |
universe@630 | 207 | * collection by other means make this iterator invalid (regardless of what cxIteratorValid() returns). |
universe@630 | 208 | * |
universe@630 | 209 | * @see CxMutIterator |
universe@500 | 210 | */ |
universe@500 | 211 | typedef struct cx_iterator_s CxIterator; |
universe@500 | 212 | |
universe@500 | 213 | /** |
universe@494 | 214 | * Checks if the iterator points to valid data. |
universe@494 | 215 | * |
universe@494 | 216 | * This is especially false for past-the-end iterators. |
universe@494 | 217 | * |
universe@630 | 218 | * @param iter the iterator |
universe@494 | 219 | * @return true iff the iterator points to valid data |
universe@494 | 220 | */ |
universe@630 | 221 | #define cxIteratorValid(iter) (iter).base.valid(&(iter)) |
universe@494 | 222 | |
universe@494 | 223 | /** |
universe@494 | 224 | * Returns a pointer to the current element. |
universe@494 | 225 | * |
universe@494 | 226 | * The behavior is undefined if this iterator is invalid. |
universe@494 | 227 | * |
universe@630 | 228 | * @param iter the iterator |
universe@494 | 229 | * @return a pointer to the current element |
universe@494 | 230 | */ |
universe@630 | 231 | #define cxIteratorCurrent(iter) (iter).base.current(&iter) |
universe@494 | 232 | |
universe@494 | 233 | /** |
universe@494 | 234 | * Advances the iterator to the next element. |
universe@494 | 235 | * |
universe@630 | 236 | * @param iter the iterator |
universe@494 | 237 | */ |
universe@630 | 238 | #define cxIteratorNext(iter) (iter).base.next(&iter) |
universe@630 | 239 | |
universe@630 | 240 | /** |
universe@630 | 241 | * Flags the current element for removal. |
universe@630 | 242 | * |
universe@630 | 243 | * @param iter the iterator |
universe@630 | 244 | * @return false if this iterator cannot remove the element |
universe@630 | 245 | */ |
universe@630 | 246 | #define cxIteratorFlagRemoval(iter) (iter).base.flag_removal(&iter) |
universe@494 | 247 | |
universe@496 | 248 | /** |
universe@496 | 249 | * Loops over an iterator. |
universe@496 | 250 | * @param type the type of the elements |
universe@496 | 251 | * @param elem the name of the iteration variable |
universe@496 | 252 | * @param iter the iterator |
universe@496 | 253 | */ |
universe@496 | 254 | #define cx_foreach(type, elem, iter) \ |
universe@630 | 255 | for (type elem; cxIteratorValid(iter) && (elem = (type)cxIteratorCurrent(iter)) != NULL ; cxIteratorNext(iter)) |
universe@496 | 256 | |
universe@628 | 257 | #endif // UCX_ITERATOR_H |