replace some hash table usage by tuples

Previously I used hash tables, which consume too much memory.  Now the
critical parts are replaced by a new hand-written library called
"tuple.h".  Now we can easily parse larger inputs.  I haven't tested
its limits, though.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/list.c b/src/list.c
index 1b9f4d4..05d760c 100644
--- a/src/list.c
+++ b/src/list.c
@@ -157,7 +157,7 @@ H_ATTR
 NUM
 list_length(const List * const restrict ls)
 {
-  return ls->len;
+  return (ls == NULL) ? 0 : ls->len;
 }
 
 BOOL
@@ -231,7 +231,7 @@ List *
 array_to_list(void **array, NUM size)
 {
   List *ls = NULL;
-  
+
   SAFE_MALLOC(List, ls, 1, return NULL;);
 
   ls->array = array;
@@ -243,6 +243,8 @@ array_to_list(void **array, NUM size)
 void
 destroy_list(List *ls, BOOL all_free_p)
 {
+  if (ls == NULL) return;
+
   if (all_free_p == 1)
     for (NUM i = 0; i < ls->len; i++)
       free(*(ls->array+i));