chessboard: Some issue with `chessboard` exercise

[ynfle]

• (ret int) syntax is used, but isn't introduced (as far as I know). This should be fixed by Functions concept #1720, but I'm not sure if it will be a prerequisite
• Out of bounds values for ranks and files aren't specified

[junedev]

Regarding the first point: functions will be a prerequisite for maps with is a prerequisite for range (chessboard) so we are ok there. We still might want to change it though ...

[ynfle]

Ok. It's a really nice feature of go!

[andrerfcsantos]

I think we should change it too.

@ynfle What do you mean by "Out of bounds values for ranks and files aren't specified"?

[ynfle]

The behaviour of the function isn't specified if the file or rank is out of bounds. There is a case where the file is out of bounds.
I'm not sure whether it needs to be specified, just wanted to bring it up

[andrerfcsantos]

Got it, it does seem a good idea to clarify that scenario,