Queue iterator

tests/foreach.c

@@ -80,9 +80,9 @@ int main(int argc, char const *argv[])
         sum1 += var;
     })
 
-    // FOR_EACH_REV(q, queue, , int, q, {
-    //     sum2 += var;
-    // })
+    FOR_EACH_REV(q, queue, , int, q, {
+        sum2 += var;
+    })
 
     // FOR_EACH_REV(d, deque, , int, d, {
     //     sum3 += var;
@@ -96,8 +96,8 @@ int main(int argc, char const *argv[])
         printf("%10s PASSED\n", "LIST");
     if (sum1 == 50005000)
         printf("%10s PASSED\n", "STACK");
-    // if (sum2 == 50005000)
-    //     printf("%10s PASSED\n", "QUEUE");
+    if (sum2 == 50005000)
+        printf("%10s PASSED\n", "QUEUE");
     // if (sum3 == 50005000)
     //     printf("%10s PASSED\n", "DEQUE");
     if (sum4 == 50005000)

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;
+}