`continue` in `while` loop with `break` as last statement

[anthonyjb]

I have a while loop as follows which is used to read data from a socket:

class GameClient

 ...

 receive: () =>
 -- Receive data from the game server
 data = ''
 err = ''

 -- Receive any data from the client
 while true
 block, err, partial = @_socket\receive(1024)

 if block
 data = data .. block
 continue

 if partial
 data = data .. partial

 break

 -- Check for data received and add it to the data map
 if data\len() > 0
 return data

 return nil

The code (receive method) compiles to the following lua:

 ...
 receive = function(self)
 local data = ''
 local err = ''
 while true do
 local _continue_0 = false
 repeat
 local block, partial
 block, err, partial = self._socket:receive(1024)
 if block then
 data = data .. block
 _continue_0 = true
 break
 end
 if partial then
 data = data .. partial
 end
 break
 _continue_0 = true
 until true
 if not _continue_0 then
 break
 end
 end
 if data:len() > 0 then
 return data
 end
 return nil
 end

Which in lua 5.2 raises a syntax error based on the following series of lines:

 break
 _continue_0 = true
 until true

Error: Syntax error: ... 'until' expected (to close 'repeat' at line 19) near '_continue_0'

The workaround I'm currently using is to change my while loop (in moonscript) to:

 while true
 block, err, partial = @_socket\receive(1024)

 if block
 data = data .. block
 continue
 else
 if partial
 data = data .. partial

 break

which compiles to to the following lua:

 receive = function(self)
 local data = ''
 local err = ''
 while true do
 local _continue_0 = false
 repeat
 local block, partial
 block, err, partial = self._socket:receive(1024)
 if block then
 data = data .. block
 _continue_0 = true
 break
 else
 if partial then
 data = data .. partial
 end
 break
 end
 _continue_0 = true
 until true
 if not _continue_0 then
 break
 end
 end
 if data:len() > 0 then
 return data
 end
 return nil
 end

[leafo]

dupe of #183

[anthonyjb]

thanks @leafo - should have looked harder (apologise). One option might be to wrap the break in an if test, so:

break
_continue_0 = true

...becomes...

if not _continue_0 then 
 break
end
_continue_0 = true