rl.c

   1 /*
   2  * rl.c
   3  * Created: Sun Feb 25 22:30:43 2001 by tek@wiw.org
   4  * Revised: Sun Feb 25 22:30:43 2001 (pending)
   5  * Copyright 2001 Julian E. C. Squires (tek@wiw.org)
   6  * This program comes with ABSOLUTELY NO WARRANTY.
   7  * $Id: rl.c,v 1.1.1.1 2001/02/26 03:19:54 tek Exp $
   8  *
   9  */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13
  14 #include "noose.h"
  15
  16 rangelist_t *rl_new(int begin, int end, rangelist_t *next);
  17 void rl_delete(rangelist_t *rl);
  18 void rl_exclude(rangelist_t **rl, int begin, int end);
  19
  20 rangelist_t *rl_new(int begin, int end, rangelist_t *next)
  21 {
  22     rangelist_t *p;
  23
  24     p = malloc(sizeof(rangelist_t));
  25     if(p == NULL) {
  26         fprintf(stderr, "%s: Out of memory.\n", PROGNAME);
  27         return NULL;
  28     }
  29     p->begin = begin;
  30     p->end = end;
  31     p->next = next;
  32     return p;
  33 }
  34
  35 void rl_delete(rangelist_t *rl)
  36 {
  37     rangelist_t *dead;
  38
  39     while(rl != NULL) {
  40         dead = rl;
  41         rl = rl->next;
  42         free(dead);
  43     }
  44     return;
  45 }
  46
  47 void rl_exclude(rangelist_t **rlp, int begin, int end)
  48 {
  49     rangelist_t *rl;
  50
  51     rl = *rlp;
  52     while(rl != NULL) {
  53         if(begin <= rl->begin && end >= rl->end) { /* no parts left */
  54             *rlp = rl->next;
  55             rl = rl->next;
  56             rl_delete(rl);
  57             continue;
  58         } else if(begin <= rl->begin && end >= rl->begin && end < rl->end) {
  59             /* shrink right */
  60             rl->begin = end+1;
  61         } else if(begin >= rl->begin && begin < rl->end && end >= rl->end) {
  62             /* shrink left */
  63             rl->end = begin-1;
  64         } else if(begin > rl->begin && end < rl->end) {
  65             /* two parts */
  66             rl->next = rl_new(end+1, rl->end, rl->next);
  67             rl->end = begin-1;
  68         }
  69
  70         rl = rl->next;
  71     }
  72 }
  73
  74 /* EOF rl.c */