#578 fixed

objectionary · Jan 20, 2022 · 8a72613 · 8a72613
1 parent 0dc94a4
commit 8a72613
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Showing 2 changed files with 21 additions and 3 deletions.
diff --git a/eo-runtime/src/main/eo/org/eolang/gray/heap.eo b/eo-runtime/src/main/eo/org/eolang/gray/heap.eo
@@ -41,5 +41,17 @@
   [address length] > pointer
     address > @
 
+    # Increment this pointer by x steps forward
+    [x] > add
+      &.^.pointer > @
+        address.add
+          length.mul x
+        length
+
+    # Decrement this pointer by x steps backward
+    [x] > sub
+      &.add > @
+        x.mul -1
+
     # One block in the heap.
     [len inverse] > block /?
diff --git a/eo-runtime/src/test/eo/org/eolang/gray/heap-tests.eo b/eo-runtime/src/test/eo/org/eolang/gray/heap-tests.eo
@@ -55,11 +55,17 @@
 [] > increments-pointer
   heap 1024 > h
   h.pointer 0 2 > p1
-  p1.add 1 > p2
+  p1.add 2 > p2
+  p2.sub 1 > p3
   and. > @
-    (p1.block 4).write ("DUDE".as-bytes)
+    (p1.block 6).write ("HELLO!".as-bytes)
     eq.
       p2.block
         2
         [b] (b.as-string > @)
-      "DE"
+      "O!"
+    eq.
+      p3.block
+        2
+        [b] (b.as-string > @)
+      "LL"