list.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3
   4
   5 #include <list.h>
   6
   7 list* freelist = NULL;
   8
   9
  10 list* make_new(list* next, void* item){
  11         list* ptr;
  12
  13         if(freelist == NULL){
  14                 ptr = malloc(sizeof(struct list));
  15         }
  16         else{
  17                 ptr = freelist;
  18                 freelist = ptr->next;
  19         }
  20
  21         ptr->next = next;
  22         ptr->item = item;
  23         return ptr;
  24 }
  25
  26 void remove_from_list(list* prev, list* node){
  27         prev->next = node->next;
  28         node->item = NULL;
  29         node->next = freelist;
  30         freelist = node;
  31 }
  32
  33
  34 list* empty(){
  35         return make_new(NULL, NULL);
  36 }
  37
  38 void push(list* L, void* item){
  39         list* ptr = make_new(L->next, item);
  40         L->next = ptr;
  41 }
  42
  43 void* pop(list* L){
  44         if(L->next){
  45                 void* item = L->next->item;
  46                 remove_from_list(L, L->next);
  47                 return item;
  48         }
  49         else{
  50                 return NULL;
  51         }
  52
  53 }
  54
  55 void append(list* L, void* item){
  56         list* ptr = L;
  57         while(ptr->next){
  58                 ptr = ptr->next;
  59         }
  60         ptr->next = make_new(NULL, item);
  61 }
  62
  63 void recycle(list* L){
  64         list* ptr = L;
  65         while(ptr->next){
  66                 ptr->next->item = NULL;
  67                 ptr = ptr->next;
  68         }
  69         ptr->next = freelist;
  70         freelist = L;
  71 }
  72
  73 int length(list* L){
  74         list* ptr = L->next;
  75         int c = 0;
  76         while(ptr){
  77                 c += 1;
  78                 ptr = ptr->next;
  79         }
  80         return c;
  81 }
  82
  83
  84
  85
  86 void print_list(list* L, void (*print)(void* item)){
  87         list* ptr = L->next;
  88         printf("(");
  89         while(ptr){
  90                 print(ptr->item);
  91                 if(ptr->next)
  92                         printf(", ");
  93                 ptr = ptr->next;
  94         }
  95         printf(")");
  96 }
  97
  98 void println_list(list* L, void (*print)(void* item)){
  99         print_list(L, print);
 100         printf("\n");
 101 }
 102
 103 void list_print_free(){
 104         list* ptr = freelist;
 105         printf("(");
 106         while(ptr){
 107                 printf("_");
 108                 if(ptr->next){
 109                         printf(", ");
 110                 }
 111                 ptr = ptr->next;
 112         }
 113         printf(")\n");
 114 }
 115
 116 void print(void* item){
 117         char* s = item;
 118         printf("%s", s);
 119 }
 120