Error message usability suggestion

[raould]

  local points:{{number}} =
     {{1,2},
      {3,4}}
  local lines = {}
  for i = 1, #points-1 do
     local pt1:{number} = points[i]

player.tl:6:10: type error, attempt to assign '({number:(number | nil)} | nil)' to '{number:(number | nil)}'

To me that is ambiguous, please
(a) make it so that the message shows the types in the same order they appear in the sources. So for a bad x=y then the error should say something like, "attempt to assign [type of x] from [type of y]"
(b) please also if possible show the exact string of source code that was typed. So for a bad x=y then the error should say something like
[on the first line] "attempt to assign [type of x] from [type of y]"
[on the 2nd line] "'x':[type of x]"
[on the 3rd line] "'y':[type of y]"
(I do not think "attempt to assign x:[type of x] from y:[type of y]" will be good because x and y could be large, and the types are already long, so the final error message would be harder for humans to grok.)