In Torch, printing any class leads to quitting Lua

[jiajunwu]

Ubuntu 14.04

After requiring 'libMalmoLua', if we init a new variable like 'a=AgentHost()', and then simply 'print a', or if you type in an interactive environment ' AgentHost() ', which will try to print the output, the program will crash and quit Lua.

This is possibly because something like a __ tostring() __ function is undefined, but I'm not sure.

[DaveyBiggers]

It's true that there are no tostring() methods defined for the Malmo objects, though I'm seeing this, rather than the crash you report:

Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio
> require 'libMalmoLua'
> a=AgentHost()
> print(a)
No such operator defined
stack traceback:
    [C]: ?
    [C]: ?
    [C]: in function 'print'
    stdin:1: in main chunk
    [C]: ?
> 

I'll look into adding tostring() methods to our bindings but for now the workaround is just not to try to print them...

[jiajunwu]

Hi David,

Yes in lua it's just an error message. In Torch (more like a wrapper over luajit), it leads to a crash.

[DaveyBiggers]

Fixed by fdc0089