Fix for Lua 5.2+ which removed table.maxn

gmodule.lua

@@ -49,14 +49,14 @@ function gModule:__init(inputs,outputs)
    -- input point for the backward graph
    local node
    local outnode = nngraph.Node({input={}})
-   for i = 1, table.maxn(outputs) do
+   for i = 1, utils.tableMaxN(outputs) do
       node = outputs[i]
       if torch.typename(node) ~= 'nngraph.Node' then
          error(utils.expectingNodeErrorMessage(node, 'outputs', i))
       end
       outnode:add(node, true)
    end
-   for i = 1, table.maxn(inputs) do
+   for i = 1, utils.tableMaxN(inputs) do
       node = inputs[i]
       if torch.typename(node) ~= 'nngraph.Node' then
          error(utils.expectingNodeErrorMessage(node, 'inputs', i))

init.lua

@@ -41,7 +41,7 @@ function Module:__call__(...)
    local mnode = nngraph.Node({module=self})
 
    local dnode
-   for i = 1, table.maxn(input) do
+   for i = 1, utils.tableMaxN(input) do
       dnode = input[i]
       if torch.typename(dnode) ~= 'nngraph.Node' then
          error(utils.expectingNodeErrorMessage(dnode, 'inputs', i))

utils.lua

@@ -25,4 +25,18 @@ function utils.expectingNodeErrorMessage(badVal, array, idx)
    end
 end
 
+--[[ Lua 5.2+ removed table.maxn, provide fallback implementation. ]]
+if table.maxn then
+   utils.tableMaxN = table.maxn
+else
+   function utils.tableMaxN(tbl)
+      local max = 0
+      for k, v in pairs(tbl) do
+         if type(k) == 'number' and k > max then
+            max = k
+         end
+      end
+      return max
+   end
+ end
 return utils