From 71a1446fe0be8df923b5f057658585031709ff5b Mon Sep 17 00:00:00 2001
From: Doyle T <dyl.thai@gmail.com>
Date: Tue, 24 Jul 2018 20:44:01 +1000
Subject: [PATCH] Add post fix/prefix operator++ and arbitrary operator+-

---
 DqnVHashTable.cpp | 47 ++++++++++++++++++++++++++++++++++++++++-------
 dqn.h             |  9 +++++++--
 2 files changed, 47 insertions(+), 9 deletions(-)

diff --git a/DqnVHashTable.cpp b/DqnVHashTable.cpp
index 8b5713e..f3f9156 100644
--- a/DqnVHashTable.cpp
+++ b/DqnVHashTable.cpp
@@ -31,7 +31,6 @@ void DqnVHashTable_Test()
 
     {
         Block blocks[]                          = {{0}, {1}, {2}, {3}, {4}};
-        bool blockSeen[DQN_ARRAY_COUNT(blocks)] = {};
 
         DqnVHashTable<Height, Block> table = {};
         DQN_DEFER(table.Free());
@@ -42,14 +41,48 @@ void DqnVHashTable_Test()
         table.Set(4, blocks[3]);
         table.Set(5, blocks[4]);
 
-        isize blocksSeen = 0;
-        for (Block const &block : table)
         {
-            DQN_ASSERT(blockSeen[block.x] == false);
-            blockSeen[block.x] = true;
-            blocksSeen++;
+            bool blockSeen[DQN_ARRAY_COUNT(blocks)] = {};
+            isize blocksSeen = 0;
+            for (Block const &block : table)
+            {
+                DQN_ASSERT(blockSeen[block.x] == false);
+                blockSeen[block.x] = true;
+                blocksSeen++;
+            }
+            DQN_ASSERT(blocksSeen == DQN_ARRAY_COUNT(blockSeen));
+            Log(Status::Ok, "Auto iterator using prefix operator++");
         }
 
-        DQN_ASSERT(blocksSeen == DQN_ARRAY_COUNT(blockSeen));
+        {
+            bool blockSeen[DQN_ARRAY_COUNT(blocks)] = {};
+            isize blocksSeen = 0;
+            for (auto it = table.begin(); it != table.end();)
+            {
+                it = it + 1;
+                Block *block = it.GetCurrItem();
+
+                DQN_ASSERT(blockSeen[block->x] == false);
+                blockSeen[block->x] = true;
+                blocksSeen++;
+            }
+            DQN_ASSERT(blocksSeen == DQN_ARRAY_COUNT(blockSeen));
+            Log(Status::Ok, "Auto iterator using operator+");
+        }
+
+        {
+            bool blockSeen[DQN_ARRAY_COUNT(blocks)] = {};
+            isize blocksSeen = 0;
+            for (auto it = table.begin(); it != table.end(); it++)
+            {
+                Block *block = it.GetCurrItem();
+
+                DQN_ASSERT(blockSeen[block->x] == false);
+                blockSeen[block->x] = true;
+                blocksSeen++;
+            }
+            DQN_ASSERT(blocksSeen == DQN_ARRAY_COUNT(blockSeen));
+            Log(Status::Ok, "Auto iterator using postfix operator++");
+        }
     }
 }
diff --git a/dqn.h b/dqn.h
index 22bd5d0..1cd2f47 100644
--- a/dqn.h
+++ b/dqn.h
@@ -2709,11 +2709,16 @@ DQN_VHASH_TABLE_TEMPLATE struct DqnVHashTable
 
         bool      operator!=(Iterator const &other) const { return !Equals(GetCurrEntry()->key, other.GetCurrEntry()->key); }
         Item     &operator* ()                      const { return *GetCurrItem(); }
-        Iterator  operator++()                            { if (++indexInBucket >= GetCurrBucket()->entryIndex) { indexInBucket = 0; indexInIndexesOfUsedBuckets++; } return *this; }
+        Iterator &operator++()                            { if (++indexInBucket >= GetCurrBucket()->entryIndex) { indexInBucket = 0; indexInIndexesOfUsedBuckets++; }                return *this; }
+        Iterator &operator--()                            { if (--indexInBucket < 0) { indexInBucket = 0; indexInIndexesOfUsedBuckets = DQN_MAX(--indexInIndexesOfUsedBuckets, 0); } return *this; }
+        Iterator  operator++(int)                         { Iterator result = *this; ++(*this); return result; }
+        Iterator  operator--(int)                         { Iterator result = *this; --(*this); return result; }
+        Iterator  operator+ (int offset)            const { Iterator result = *this; DQN_FOR_EACH(i, offset) { (offset > 0) ? ++result : --result; } return result; } // TODO(doyle): Improve
+        Iterator  operator- (int offset)            const { Iterator result = *this; DQN_FOR_EACH(i, offset) { (offset > 0) ? --result : ++result; } return result; } // TODO(doyle): Improve
     };
 
     Iterator begin() { return Iterator(this); }
-    Iterator end()   { isize lastBucketIndex = indexesOfUsedBuckets[indexInIndexesOfUsedBuckets - 1]; isize lastIndexInBucket = DQN_MAX((buckets + lastBucketIndex)->entryIndex - 1, 0); return Iterator(this, DQN_MAX(lastBucketIndex, 0), DQN_MAX(lastIndexInBucket, 0)); }
+    Iterator end()   { isize lastBucketIndex = indexesOfUsedBuckets[indexInIndexesOfUsedBuckets - 1]; isize lastIndexInBucket = (buckets + lastBucketIndex)->entryIndex - 1; return Iterator(this, DQN_MAX(lastBucketIndex, 0), DQN_MAX(lastIndexInBucket, 0)); }
 };
 
 DQN_VHASH_TABLE_TEMPLATE void DQN_VHASH_TABLE_DECL::LazyInit(isize size)