Proto: meaning etc.

nellie/helper.lua

@@ -27,8 +27,15 @@ end
 id = function(...) return ... end
 
 function union(t0,t1)
-  for index,item in pairs(t0) do
-    t0[index] = t1
+  for index,item in pairs(t1) do
+    t0[index] = t1[index]
+  end
+  return t0
+end
+
+function union_all(t0,...)
+  for _,t1 in pairs({...}) do
+    union(t0,t1)
   end
   return t0
 end
@@ -193,7 +200,7 @@ function read(path)
   local file = io.open(path)
   if not file then
     error(
-      string.match("Could not open file '%s'.",path),3
+      string.format("Could not open file '%s'.",path),3
     )
   end
   local content = file:read("a")