Queue iterator

tests/iterators/queue.c

@@ -0,0 +1,53 @@
+// Checks if the queue iterator can go back and forward in the queue without
+// hitting invalid states or a null pointer. Check is done visually.
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include "../../src/queue.h"
+
+QUEUE_GENERATE(q, queue, static, , int)
+
+int main(int argc, char const *argv[])
+{
+    size_t i;
+    int r;
+
+    // Initliazie queue and add some elements
+    queue *q = q_new(10);
+    for (int i = 0; i < 10; i++)
+        q_enqueue(q, i);
+
+    // Initialize iterator
+    queue_iter iter;
+    q_iter(&iter, q);
+
+    // Make the iterator go back and forward
+    for (int j = 0; j < 4; j++)
+    {
+        while (q_iter_next(&iter, &r, &i))
+            printf("C[%2d] = %2d\n", i, r);
+        printf("\n");
+        while (q_iter_prev(&iter, &r, &i))
+            printf("C[%2d] = %2d\n", i, r);
+        printf("\n\n");
+    }
+
+    for (q_iter_tostart(&iter); !q_iter_end(&iter); /**/)
+    {
+        q_iter_next(&iter, &r, &i);
+        printf("Q[%2d] = %2d\n", i, r);
+    }
+
+    printf("\n");
+
+    for (q_iter_toend(&iter); !q_iter_start(&iter); /**/)
+    {
+        q_iter_prev(&iter, &r, &i);
+        printf("Q[%2d] = %2d\n", i, r);
+    }
+
+    q_free(q);
+
+    return 0;
+}