src/libpspp/string-set.h

   1 /* PSPP - a program for statistical analysis.
   2    Copyright (C) 2009, 2011 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  16
  17 #ifndef LIBPSPP_STRING_SET_H
  18 #define LIBPSPP_STRING_SET_H
  19
  20 /* Set of unique strings.
  21
  22    This is a convenient wrapper around a "struct hmap" for storing strings. */
  23
  24 #include <stdbool.h>
  25 #include "libpspp/hmap.h"
  26
  27 /* A node in the string set. */
  28 struct string_set_node
  29   {
  30     struct hmap_node hmap_node;
  31     char *string;
  32   };
  33
  34 /* Returns the string within NODE.  The caller must not modify or free the
  35    returned string. */
  36 static inline const char *
  37 string_set_node_get_string (const struct string_set_node *node)
  38 {
  39   return node->string;
  40 }
  41 \f
  42 /* An unordered set of unique strings. */
  43 struct string_set
  44   {
  45     struct hmap hmap;
  46   };
  47
  48 /* Suitable for use as the initializer for a string_set named SET.  Typical
  49    usage:
  50        struct string_set set = STRING_SET_INITIALIZER (set);
  51    STRING_SET_INITIALIZER is an alternative to calling string_set_init. */
  52 #define STRING_SET_INITIALIZER(SET) { HMAP_INITIALIZER ((SET).hmap) }
  53
  54 void string_set_init (struct string_set *);
  55 void string_set_clone (struct string_set *, const struct string_set *);
  56 void string_set_swap (struct string_set *, struct string_set *);
  57 void string_set_destroy (struct string_set *);
  58
  59 static inline size_t string_set_count (const struct string_set *);
  60 static inline bool string_set_is_empty (const struct string_set *);
  61
  62 bool string_set_contains (const struct string_set *, const char *);
  63 struct string_set_node *string_set_find_node (const struct string_set *,
  64                                               const char *);
  65
  66 bool string_set_insert (struct string_set *, const char *);
  67 bool string_set_insert_nocopy (struct string_set *, char *);
  68 bool string_set_delete (struct string_set *, const char *);
  69 void string_set_delete_node (struct string_set *, struct string_set_node *);
  70 char *string_set_delete_nofree (struct string_set *, struct string_set_node *);
  71
  72 void string_set_clear (struct string_set *);
  73 void string_set_union (struct string_set *, const struct string_set *);
  74 void string_set_union_and_intersection (struct string_set *,
  75                                         struct string_set *);
  76 void string_set_intersect (struct string_set *, const struct string_set *);
  77 void string_set_subtract (struct string_set *, const struct string_set *);
  78
  79 static inline const struct string_set_node *string_set_first (
  80   const struct string_set *);
  81 static inline const struct string_set_node *string_set_next (
  82   const struct string_set *, const struct string_set_node *);
  83
  84 /* Macros for conveniently iterating through a string_set, e.g. to print all of
  85    the strings in "my_set":
  86
  87    struct string_set_node *node;
  88    const char *string;
  89
  90    STRING_SET_FOR_EACH (string, node, &my_set)
  91      puts (string);
  92    */
  93 #define STRING_SET_FOR_EACH(STRING, NODE, SET)                  \
  94         for ((NODE) = string_set_first (SET);                   \
  95              ((NODE) != NULL                                    \
  96               ? ((STRING) = string_set_node_get_string (NODE),  \
  97                  1)                                             \
  98               : 0);                                             \
  99              (NODE) = string_set_next (SET, NODE))
 100 #define STRING_SET_FOR_EACH_SAFE(STRING, NODE, NEXT, SET)       \
 101         for ((NODE) = string_set_first (SET);                   \
 102              ((NODE) != NULL                                    \
 103               ? ((STRING) = string_set_node_get_string (NODE),  \
 104                  (NEXT) = string_set_next (SET, NODE),          \
 105                  1)                                             \
 106               : 0);                                             \
 107              (NODE) = (NEXT))
 108 \f
 109 /* Returns the number of strings currently in SET. */
 110 static inline size_t
 111 string_set_count (const struct string_set *set)
 112 {
 113   return hmap_count (&set->hmap);
 114 }
 115
 116 /* Returns true if SET currently contains no strings, false otherwise. */
 117 static inline bool
 118 string_set_is_empty (const struct string_set *set)
 119 {
 120   return hmap_is_empty (&set->hmap);
 121 }
 122
 123 /* Returns the first node in SET, or a null pointer if SET is empty.  See the
 124    hmap_first function for information about complexity (O(1) amortized) and
 125    ordering (arbitrary).
 126
 127    The STRING_SET_FOR_EACH and STRING_SET_FOR_EACH_SAFE macros provide
 128    convenient ways to iterate over all the nodes in a string set. */
 129 static inline const struct string_set_node *
 130 string_set_first (const struct string_set *set)
 131 {
 132   return HMAP_FIRST (struct string_set_node, hmap_node, &set->hmap);
 133 }
 134
 135 /* Returns the next node in SET following NODE, or a null pointer if NODE is
 136    the last node in SET.  See the hmap_next function for information about
 137    complexity (O(1) amortized) and ordering (arbitrary).
 138
 139    The STRING_SET_FOR_EACH and STRING_SET_FOR_EACH_SAFE macros provide
 140    convenient ways to iterate over all the nodes in a string set. */
 141 static inline const struct string_set_node *
 142 string_set_next (const struct string_set *set,
 143                  const struct string_set_node *node)
 144 {
 145   return HMAP_NEXT (node, struct string_set_node, hmap_node, &set->hmap);
 146 }
 147
 148 #endif /* libpspp/string-set.h */