Finished manual gearbox

koptilnya/libs/table.txt

@@ -93,3 +93,15 @@ function table.find(tbl, predicate)
         end
     end
 end
+
+function table.reduce(tbl, func, init)
+    init = init or 0
+
+    local accum = init
+
+    for _, field in ipairs(tbl) do
+        accum = accum + func(field)
+    end
+
+    return accum
+end

koptilnya/libs/watcher.txt

@@ -0,0 +1,14 @@
+function watcher(expr, cbk)
+    local lastVal = expr()
+
+    return function()
+        local newVal = expr()
+
+        if newVal == lastVal then
+            return
+        end
+
+        cbk(newVal, lastVal)
+        lastVal = newVal
+    end
+end