src/iterator.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2024 Mike Becker, Olaf Wintermann All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "cx/iterator.h"

#include <string.h>
#include <assert.h>

static bool cx_iter_valid(const void *it) {
    const struct cx_iterator_s *iter = it;
    return iter->index < iter->elem_count;
}

static void *cx_iter_current(const void *it) {
    const struct cx_iterator_s *iter = it;
    return iter->elem_handle;
}

static void *cx_iter_current_ptr(const void *it) {
    const struct cx_iterator_s *iter = it;
    return *(void**)iter->elem_handle;
}

static void cx_iter_next(void *it) {
    struct cx_iterator_s *iter = it;
    assert(!iter->base.remove);
    iter->index++;
    iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
}

CxIterator cxIterator(const void *array, size_t elem_size, size_t elem_count) {
    CxIterator iter;

    iter.index = 0;
    iter.src_handle = (void*) array;
    iter.elem_handle = (void*) array;
    iter.elem_size = elem_size;
    iter.elem_count = array == NULL ? 0 : elem_count;
    iter.base.valid = cx_iter_valid;
    iter.base.current = cx_iter_current;
    iter.base.next = cx_iter_next;
    iter.base.valid_impl = NULL;
    iter.base.current_impl = NULL;
    iter.base.next_impl = NULL;
    iter.base.remove = false;
    iter.base.allow_remove = true;

    return iter;
}

CxIterator cxIteratorPtr(const void *array, size_t elem_count) {
    CxIterator iter = cxIterator(array, sizeof(void*), elem_count);
    iter.base.current = cx_iter_current_ptr;
    return iter;
}