Re: Construction of function pipeline wrapper in runtime

["Alexander Gladysh" <agladysh@...>]

Heh, I've found more cheap 'obvious' solution than I thought... Still,
I don't like that unpack(args) there. ;)

 make_wrapper = function(...)
   local types = {...}
   local nargs = #types
   return function(sink)
     local f = sink
     local args = { }
     local n = nargs

     local collector
     collector = function(a)
       local i = 1 + nargs - n
       assert(type(a) == types[i], "Bad argument " .. i .. ", " ..
types[i] .. " expected")
       args[i] = a
       if n > 1 then
         n = n - 1
         return collector
       else
         return sink(unpack(args))
       end
     end
     return collector
   end
 end

 name_data = make_wrapper("string", "table")
 foo = name_data(function(name, data) print(name, data.data) end)
 foo "one" { data = "two" }  --  Prints 'one two'.

Alexander.