minishell/src/parser/wordlist/wordlist.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   wordlist.c                                         :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2025/02/13 17:07:01 by khais             #+#    #+#             */
/*   Updated: 2025/02/26 16:57:59 by khais            ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "wordlist.h"
#include "ft_printf.h"
#include "libft.h"
#include "unistd.h"
#include <stdlib.h>

/*
** create a new wordlist element, with next set to null and word set to the
** passed worddesc.
**
** in case of error, return null
*/
t_wordlist	*wordlist_create(t_worddesc *word)
{
	t_wordlist	*retvalue;

	retvalue = ft_calloc(1, sizeof(t_wordlist));
	if (retvalue == NULL)
		return (NULL);
	retvalue->next = NULL;
	retvalue->word = word;
	return (retvalue);
}

/*
** free all memory associated with this wordlist.
*/
void	wordlist_destroy(t_wordlist *wordlist)
{
	t_wordlist	*prev;

	while (wordlist != NULL)
	{
		ft_dprintf(STDERR_FILENO, "wordlist_destroy: %p\n", wordlist);
		worddesc_destroy(wordlist->word);
		prev = wordlist;
		wordlist = wordlist->next;
		free(prev);
	}
}

/*
** get the worddesc at position idx in the given wordlist.
**
** return null if out of range or wordlist is null
*/
t_worddesc	*wordlist_get(t_wordlist *wordlist, int idx)
{
	if (wordlist == NULL || idx < 0)
		return (NULL);
	while (idx > 0 && wordlist != NULL)
	{
		wordlist = wordlist->next;
		idx--;
	}
	if (wordlist == NULL)
		return (NULL);
	return (wordlist->word);
}

/*
** push the given worddesc to the end of the given wordlist.
**
** if wordlist is null, create a new wordlist.
**
** returns a pointer to the first element in the wordlist.
**
** if malloc failure is encountered, all memory for this wordlist is freed, and
** null is returned.
*/
t_wordlist	*wordlist_push(t_wordlist *wordlist, t_worddesc *worddesc)
{
	t_wordlist	*start;

	if (wordlist == NULL)
		return (wordlist_create(worddesc));
	start = wordlist;
	while (wordlist->next != NULL)
		wordlist = wordlist->next;
	wordlist->next = wordlist_create(worddesc);
	if (wordlist->next == NULL)
		return (wordlist_destroy(start), NULL);
	return (start);
}

/*
** remove and return the first element in the given wordlist
**
** If wordlist is empty, return null.
*/
t_worddesc	*wordlist_pop(t_wordlist **wordlist)
{
	t_wordlist	*first;
	t_worddesc	*word;

	if ((*wordlist) == NULL)
		return (NULL);
	first = *wordlist;
	(*wordlist) = first->next;
	word = first->word;
	free(first);
	ft_dprintf(STDERR_FILENO, "freed a wordlist in wordlist_pop: %p\n", first);
	return (word);
}