Compile-time tail-call avoidance flag?

[aleclarson]

It would be cool if there was a CLI flag that compiled Moonscript with an avoidance of tail calls. The use case is debugging, of course.

This is probably hard to accomplish, but I figured I would make the suggestion anyway.

[leafo]

How do you think it should modify the code?

[refi64]

Would something like this work?

return f! 

To:

tmp = f()
return tmp

LuaJIT may outsmart this, though. In that case, creating a 1-element table could also work...

[leafo]

That won't work for functions that return multiple values, so a table would be needed

[aleclarson]

Just wrap tail calls like so:

function tail(...)
  return ...
end

function bar(i)
  print(debug.traceback())
  return i + 1, i + 2
end

function foo(i)
  -- The tail call
  return tail(bar(i))
end

print(foo(1))

Works in both Lua 5.1 and LuaJIT.