131 lines
3.1 KiB
C
131 lines
3.1 KiB
C
/* ****************************************************************************
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* iter/iter.c -- iterator internals.
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* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
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*
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* This file is part of libcasio.
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* libcasio is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 3.0 of the License,
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* or (at your option) any later version.
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*
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* libcasio is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with libcasio; if not, see <http://www.gnu.org/licenses/>.
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* ************************************************************************* */
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#include "../internals.h"
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/* Internal structure of an iterator. */
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struct casio_iter_s {
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int stopped, has_last;
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void *last;
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void *cookie;
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casio_next_t *next;
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casio_nextfree_t *nextfree;
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casio_end_t *end;
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};
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/* `default_next()`: default next function. */
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CASIO_LOCAL int default_next(void *cookie, void **ptr)
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{
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(void)cookie;
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(void)ptr;
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return (casio_error_iter);
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}
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/* `default_nextfree()`: default nextfree function. */
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CASIO_LOCAL void default_nextfree(void *cookie, void *ptr)
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{
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/* Do not free. */
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(void)cookie;
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(void)ptr;
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}
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/* `default_end()`: default iterator end function. */
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CASIO_LOCAL void default_end(void *cookie)
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{
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(void)cookie;
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}
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/* `casio_iter()`: create an iterator. */
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int CASIO_EXPORT casio_iter(casio_iter_t **iterp, void *cookie,
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casio_iter_funcs_t const *funcs)
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{
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casio_iter_t *iter;
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/* Allocate the iterator. */
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iter = casio_alloc(1, sizeof(*iter));
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if (!iter) {
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if (funcs->casio_iterfunc_end)
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(*funcs->casio_iterfunc_end)(cookie);
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return (casio_error_alloc);
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}
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/* Prepare the iterator. */
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iter->stopped = 0;
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iter->has_last = 0;
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iter->cookie = cookie;
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iter->next = funcs->casio_iterfunc_next;
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if (!iter->next)
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iter->next = &default_next;
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iter->nextfree = funcs->casio_iterfunc_nextfree;
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if (!iter->nextfree)
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iter->nextfree = &default_nextfree;
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iter->end = funcs->casio_iterfunc_end;
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if (!iter->end)
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iter->end = &default_end;
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*iterp = iter;
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return (0);
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}
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/* `casio_next()`: get the next element from an iterator. */
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int CASIO_EXPORT casio_next(casio_iter_t *iter, void **ptrp)
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{
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int err;
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if (iter->stopped)
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return (casio_error_iter);
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if (iter->has_last) {
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(*iter->nextfree)(iter->cookie, iter->last);
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iter->has_last = 0;
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}
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err = (*iter->next)(iter->cookie, ptrp);
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if (err == casio_error_iter) {
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iter->stopped = 1;
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return (err);
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} else if (err)
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return (err);
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iter->has_last = 1;
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iter->last = *ptrp;
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return (0);
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}
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/* `casio_end()`: end and free the iterator. */
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void CASIO_EXPORT casio_end(casio_iter_t *iter)
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{
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if (iter->has_last) {
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(*iter->nextfree)(iter->cookie, iter->last);
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iter->has_last = 0;
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}
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(*iter->end)(iter->cookie);
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casio_free(iter);
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}
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