1 files changed, 101 insertions, 17 deletions

diff --git a/src/grammar.c b/src/grammar.c
index 9265ef5..fd38ac8 100644
--- a/src/grammar.c
+++ b/src/grammar.c
@@ -10,7 +10,14 @@ struct Rule_s {
   List *right;
 };
 
-TNT *new_tnt(int type, ...)
+struct Grammar_s {
+  List *rules;
+  /* a list of names of non-terminals */
+  List *names;
+};
+
+TNT *
+new_tnt(int type, ...)
 {
   va_list args;
   va_start(args, type);
@@ -26,10 +33,11 @@ TNT *new_tnt(int type, ...)
   return result;
 }
 
-Rule *new_rule(NT left, List *right)
+Rule *
+new_rule(NT left, List *right)
 {
   if (!right) return NULL;
-  
+
   Rule *rule = MYALLOC(Rule, 1);
 
   rule->left = left;
@@ -38,7 +46,22 @@ Rule *new_rule(NT left, List *right)
   return rule;
 }
 
-void print_tnt(void *element)
+Grammar *
+new_grammar()
+{
+  Grammar *g = MYALLOC(Grammar, 1);
+  return g;
+}
+
+void
+build_grammar(Grammar *g, List *rules, List *names)
+{
+  g->rules = rules;
+  g->names = names;
+}
+
+void
+print_tnt(void *element)
 {
   TNT *tnt = (TNT*) element;
 
@@ -48,35 +71,55 @@ void print_tnt(void *element)
     printf("T %lu, ", tnt->data.t);
 }
 
-void print_rule(void *r)
+void
+print_rule(void *r)
 {
-  Rule *rule = (Rule *)r;
-  printf("Rule: NT %u => ", rule->left);
-  
+  Rule *rule = (Rule *) r;
+  printf("Rule: %u => ", rule->left);
+
   map_list(rule->right, print_tnt);
 
   printf("\n");
 }
 
-void print_grammar(Grammar g)
+/* a local function pointer */
+void
+print_name(void *element)
+{
+  char *str = (char *) element;
+  printf("%s", str);
+}
+
+/* a local function pointer */
+void
+print_sep()
+{
+  printf(", ");
+}
+
+void
+print_grammar(Grammar *g)
 {
   printf("Printing a grammar:\n");
-  map_list(g, print_rule);
+  map_list_between(g->names, print_name, print_sep);
+  printf("\n");
+  map_list(g->rules, print_rule);
   printf("\n");
 }
 
-List *new_tnt_string(char *format, int format_len, ...)
+List *
+new_tnt_string(char *format, int format_len, ...)
 {
   /* FORMAT_LEN does not include the terminating null byte, so it
      should be > 0. */
-  
+
   if (format_len <= 0) return NULL;
-  
+
   List *result = new_list();
-  
+
   va_list args;
   va_start(args, format_len);
-  
+
   for (int point = 0; point < format_len; point++) {
     switch (*(format+point)) {
     case 'n':
@@ -99,8 +142,49 @@ List *new_tnt_string(char *format, int format_len, ...)
   return result;
 }
 
-void destroy_rule(Rule *rule)
+void
+destroy_rule(void *rule, int flag)
 {
-  destroy_list(rule->right, 1);
+  Rule * r = (Rule *) rule;
+  destroy_list(r->right, flag);
   free(rule);
 }
+
+void
+destroy_rule_and_free_all(void *rule)
+{
+  destroy_rule(rule, 1);
+}
+
+void
+destroy_rule_and_free_first(void *rule)
+{
+  destroy_rule(rule, 2);
+}
+
+void
+destroy_rule_no_free(void *rule)
+{
+  destroy_rule(rule, 0);
+}
+
+void
+destroy_grammar(void *grammar, int flag)
+{
+  Grammar *g = (Grammar *) grammar;
+
+  switch (flag) {
+  case 0:
+    map_list(g->rules, destroy_rule_no_free);
+    break;
+  case 1:
+    map_list(g->rules, destroy_rule_and_free_all);
+    break;
+  default:
+    map_list(g->rules, destroy_rule_and_free_first);
+    break;    
+  }
+
+  destroy_list(g->rules, 0);
+  destroy_list(g->names, flag);
+}