feat: Lua-style array append support in Bytearray

dev/tests/bytearray.lua

@@ -0,0 +1,8 @@
+local arr = Bytearray()
+assert(#arr == 0)
+
+for i=1,10 do
+    arr[i] = 10 - i
+    assert(#arr == i)
+    assert(arr[i] == 10 - i)
+end

res/modules/internal/bytearray.lua

@@ -32,8 +32,7 @@ local function count_elements(b)
     return elems
 end
 
-local bytearray_methods = {
-    append=function(self, b)
+local function append(self, b)
     local elems = count_elements(b)
     if self.size + elems > self.capacity then
         grow_buffer(self, elems)
@@ -46,7 +45,10 @@ local bytearray_methods = {
         end
     end
     self.size = self.size + elems
-    end,
+end
+
+local bytearray_methods = {
+    append=append,
     insert=function(self, index, b)
         local elems = count_elements(b)
         if self.size + elems >= self.capacity then
@@ -102,7 +104,9 @@ local bytearray_mt = {
         return self.bytes[key - 1]
     end,
     __newindex = function(self, key, value)
-        if key <= 0 or key > self.size then
+        if key == self.size + 1 then
+            return append(self, value)
+        elseif key <= 0 or key > self.size then
             return
         end
         self.bytes[key - 1] = value