Fix the code to actually produce a tree

As the previous commit was only checked to compile there were some
minor defects. Notably the parser stack was not initialized properly.
It has to return state_num 0 when empty, which was solved by inserting
a dummy state 0 wih no node attached.

diff --git a/ft_parse/ft_parse.c b/ft_parse/ft_parse.c
index bef5a61014cd8750b7e815d357835dac219b68ac..e101c5cf60c14b1351b250633243f56eb08f2627 100644 (file)
--- a/ft_parse/ft_parse.c
+++ b/ft_parse/ft_parse.c
@@ -6,7 +6,7 @@
 /*   By: ljiriste <ljiriste@student.42prague.com>   +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/05/20 20:51:36 by ljiriste          #+#    #+#             */
-/*   Updated: 2024/06/20 17:45:45 by ljiriste         ###   ########.fr       */
+/*   Updated: 2024/06/21 09:39:33 by ljiriste         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -20,6 +20,8 @@ void  ft_parse_tree_free(void *v_node)
        t_parse_tree_node       *node;
 
        node = v_node;
+       if (!node)
+               return ;
        ft_vec_free(&node->children, ft_parse_tree_free);
        free_token(&node->token);
        return ;
@@ -30,6 +32,8 @@ void  ft_stack_element_free(void *v_el)
        t_parser_stack_element  *el;
 
        el = v_el;
+       if (!el)
+               return ;
        ft_parse_tree_free(el->node);
        return ;
 }
@@ -114,7 +118,18 @@ int        follow_rule(t_stack *stack, size_t rule_num, t_parsing_table *table)
        return (ft_stack_push(stack, &element) != success || element.state_num < 0);
 }
 
-t_parse_tree_node      *ft_parse(__attribute__((unused)) t_vec *tokens, __attribute__((unused)) t_parsing_table *table)
+void   initialize_parser_stack(t_stack *stack)
+{
+       t_parser_stack_element  zero;
+
+       zero.state_num = 0;
+       zero.node = NULL;
+       ft_stack_init(stack, sizeof(t_parser_stack_element));
+       ft_stack_push(stack, &zero);
+       return ;
+}
+
+t_parse_tree_node      *ft_parse(t_vec *tokens, t_parsing_table *table)
 {
        t_stack                         stack;
        size_t                          i;
@@ -124,13 +139,13 @@ t_parse_tree_node *ft_parse(__attribute__((unused)) t_vec *tokens, __attribute__
        ssize_t                         column;
        t_parse_tree_node       *root;
 
-       ft_stack_init(&stack, sizeof(t_parser_stack_element));
+       initialize_parser_stack(&stack);
        i = 0;
        while (1)
        {
                if (i < tokens->size)
                        token = *(t_token *)ft_vec_access(tokens, i);
-               if (i == tokens->size)
+               else if (i == tokens->size)
                        token = (t_token){.type = "$", .str = NULL};
                else
                {
@@ -140,7 +155,7 @@ t_parse_tree_node   *ft_parse(__attribute__((unused)) t_vec *tokens, __attribute__
                state = ft_vec_access(&table->states,
                        ((t_parser_stack_element *)ft_stack_top(&stack))->state_num);
                column = find_token_index(token, &table->tokens);
-               if (column < 0 || (size_t)column + 1 > table->terminal_tokens_num)
+               if (column < 0 || (size_t)column > table->terminal_tokens_num)
                {
                        ft_stack_free(&stack, ft_stack_element_free);
                        return (NULL);