PRINT_ITEM does not put spaces between items

[Solumin]

https://docs.python.org/2/reference/simple_stmts.html#print
"A space is written before each object is (converted and) written, unless the output system believes it is positioned at the beginning of a line. This is the case (1) when no characters have yet been written to standard output, (2) when the last character written to standard output is a whitespace character except ' ', or (3) when the last write operation on standard output was not a print statement. (In some cases it may be functional to write an empty string to standard output for this reason.)"

[Solumin]

A couple thoughts on this.

One option is to "cheat" and look at the next instruction. If it's a PRINT_ITEM(_TO), add a space. If it's anything else, don't.

Another way is to track what we've printed and if it matches the "at new line" criteria above.
If:

• No characters have been written (interpreter has just been initialized/restarted)
• The last character printed was a whitespace char other than ' '
• Something besides PRINT_ITEM/PRINT_NEWLINE output to stdout (how do we check this?)
  then we don't put a space.

I think the actual Python interpreter keeps state on each file object, marking if it has been written to, keeping track if a space is needed, etc. We could do this, too, except we don't support files yet.

[cibelemf]

Maybe we should wait to see if we will be able to support files and try the solution where we keep the states.