mdw@git.distorted.org.uk Git - become/blob - src/set.c

   1 /* -*-c-*-
   2  *
   3  * $Id: set.c,v 1.2 1997/08/04 10:24:25 mdw Exp $
   4  *
   5  * Management of sets (for the use of the class expression handler)
   6  *
   7  * (c) 1997 EBI
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of `become'
  13  *
  14  * `Become' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `Become' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `become'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: set.c,v $
  32  * Revision 1.2  1997/08/04 10:24:25  mdw
  33  * Sources placed under CVS control.
  34  *
  35  * Revision 1.1  1997/07/21  13:47:44  mdw
  36  * Initial revision
  37  *
  38  */
  39
  40 /*----- Header files ------------------------------------------------------*/
  41
  42 /* --- ANSI headers --- */
  43
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 /* --- Local headers --- */
  49
  50 #include "set.h"
  51 #include "sym.h"
  52 #include "utils.h"
  53
  54 /*----- Main code ---------------------------------------------------------*/
  55
  56 /* --- @set_subtract@ --- *
  57  *
  58  * Arguments:   @sym_table *a@ = pointer to table @A@
  59  *              @sym_table *b@ = pointer to table @B@
  60  *
  61  * Returns:     A symbol table containing all the elements in @A@ which don't
  62  *              appear in @B@.
  63  *
  64  * Use:         Subtracts a symbol table from another symbol table.  Assumes
  65  *              that there's no data following the actual @sym_base@ block
  66  *              for each item in the table.
  67  */
  68
  69 sym_table *set_subtract(sym_table *a, sym_table *b)
  70 {
  71   sym_table *c = xmalloc(sizeof(*c));
  72   sym_iter i;
  73   sym_base *s;
  74   unsigned f;
  75
  76   sym_createTable(c);
  77   for (sym_createIter(&i, a); (s = sym_next(&i)) != 0; ) {
  78     if (!sym_find(b, s->name, s->len, 0, &f))
  79       sym_find(c, s->name, s->len, sizeof(sym_base), 0);
  80   }
  81
  82   return (c);
  83 }
  84
  85 /* --- @set_intersect@ --- *
  86  *
  87  * Arguments:   @sym_table *a@ = pointer to table @A@
  88  *              @sym_table *b@ = pointer to table @B@
  89  *
  90  * Returns:     A symbol table containing all the elements in @A@ which also
  91  *              appear in @B@.
  92  *
  93  * Use:         Constructs the intersection of two symbol tables.  Assumes
  94  *              that there's no data following the actual @sym_base@ block
  95  *              for each item in the table.
  96  */
  97
  98 sym_table *set_intersect(sym_table *a, sym_table *b)
  99 {
 100   sym_table *c = xmalloc(sizeof(*c));
 101   sym_iter i;
 102   sym_base *s;
 103   unsigned f;
 104
 105   sym_createTable(c);
 106   for (sym_createIter(&i, a); (s = sym_next(&i)) != 0; ) {
 107     if (sym_find(b, s->name, s->len, 0, &f))
 108       sym_find(c, s->name, s->len, sizeof(sym_base), 0);
 109   }
 110
 111   return (c);
 112 }
 113
 114 /* --- @set_union@ --- *
 115  *
 116  * Arguments:   @sym_table *a@ = pointer to table @A@
 117  *              @sym_table *b@ = pointer to table @B@
 118  *
 119  * Returns:     A symbol table containing all the elements in @A@ and those
 120  *              in @B@.
 121  *
 122  * Use:         Constructs the union of two symbol tables.  Assumes that
 123  *              there's no data following the actual @sym_base@ block for
 124  *              each item in the table.
 125  */
 126
 127 sym_table *set_union(sym_table *a, sym_table *b)
 128 {
 129   sym_table *c = xmalloc(sizeof(*c));
 130   sym_iter i;
 131   sym_base *s;
 132
 133   sym_createTable(c);
 134   for (sym_createIter(&i, a); (s = sym_next(&i)) != 0; )
 135     sym_find(c, s->name, s->len, sizeof(sym_base), 0);
 136
 137   for (sym_createIter(&i, b); (s = sym_next(&i)) != 0; )
 138     sym_find(c, s->name, s->len, sizeof(sym_base), 0);
 139
 140   return (c);
 141 }
 142
 143 /* --- @set_copy@ --- *
 144  *
 145  * Arguments:   @sym_table *a@ = pointer to table
 146  *
 147  * Returns:     A copy of the symbol table.
 148  *
 149  * Use:         Copies a symbol table.  Same assumptions again...
 150  */
 151
 152 sym_table *set_copy(sym_table *a)
 153 {
 154   sym_table *c = xmalloc(sizeof(*c));
 155   sym_iter i;
 156   sym_base *s;
 157
 158   for (sym_createIter(&i, a); (s = sym_next(&i)) != 0; )
 159     sym_find(c, s->name, s->len, sizeof(sym_base), 0);
 160
 161   return (c);
 162 }
 163
 164 /*----- That's all, folks -------------------------------------------------*/