Deque iterator

tests/foreach.c

@@ -84,9 +84,9 @@ int main(int argc, char const *argv[])
         sum2 += var;
     })
 
-    // FOR_EACH_REV(d, deque, , int, d, {
-    //     sum3 += var;
-    // })
+    FOR_EACH_REV(d, deque, , int, d, {
+        sum3 += var;
+    })
 
     FOR_EACH_REV(ll, linked, , int, ll, {
         sum4 += var;
@@ -98,8 +98,8 @@ int main(int argc, char const *argv[])
         printf("%10s PASSED\n", "STACK");
     if (sum2 == 50005000)
         printf("%10s PASSED\n", "QUEUE");
-    // if (sum3 == 50005000)
-    //     printf("%10s PASSED\n", "DEQUE");
+    if (sum3 == 50005000)
+        printf("%10s PASSED\n", "DEQUE");
     if (sum4 == 50005000)
         printf("%10s PASSED\n", "LINKEDLIST");
 

tests/iterators/deque.c

@@ -0,0 +1,55 @@
+// Checks if the deque iterator can go back and forward in the deque 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/deque.h"
+
+DEQUE_GENERATE(d, deque, static, , int)
+
+int main(int argc, char const *argv[])
+{
+    size_t i;
+    int r;
+
+    // Initliazie deque and add some elements
+    deque *d = d_new(10);
+    for (int i = 0; i < 10; i++)
+    {
+        i % 2 == 0 ? d_push_back(d, i) : d_push_front(d, i);
+    }
+
+    // Initialize iterator
+    deque_iter iter;
+    d_iter(&iter, d);
+
+    // Make the iterator go back and forward
+    for (int j = 0; j < 4; j++)
+    {
+        while (d_iter_next(&iter, &r, &i))
+            printf("C[%2d] = %2d\n", i, r);
+        printf("\n");
+        while (d_iter_prev(&iter, &r, &i))
+            printf("C[%2d] = %2d\n", i, r);
+        printf("\n\n");
+    }
+
+    for (d_iter_tostart(&iter); !d_iter_end(&iter); /**/)
+    {
+        d_iter_next(&iter, &r, &i);
+        printf("D[%2d] = %2d\n", i, r);
+    }
+
+    printf("\n");
+
+    for (d_iter_toend(&iter); !d_iter_start(&iter); /**/)
+    {
+        d_iter_prev(&iter, &r, &i);
+        printf("D[%2d] = %2d\n", i, r);
+    }
+
+    d_free(d);
+
+    return 0;
+}