Fixed type of probability slot of tiled-tileset-tile to (or null real…

[nobody-significant]

…) to reconcile type with the ttileset-tile struct.

At the present time, the probability slot of the struct ttileset-tile is just copied over when making instances of tiled-tileset-tile and animated-tile (see lines

cl-tiled/src/tiled.lisp

Line 1070 in 2b8731e

:probability probability

and

cl-tiled/src/tiled.lisp

Line 1076 in 2b8731e

:probability probability

), but the types of the slots are incompatible.

tiled-tileset-tile`` and animated-tileusereal``` (

cl-tiled/src/tiled.lisp

Line 132 in 2b8731e

:type real

)

but ttileset-tile uses (or null real) (

cl-tiled/src/tiled-data.lisp

Line 137 in 2b8731e

(probability nil :type (or null real))

).

This PR reconciles to two by changing the type of the slot for tiled-tileset-tile (animated-tile inherits from it) to (or null real). It could of course be reconciled the other way, though that seemed like it required more changes (I could be wrong on this).

[Zulu-Inuoe]

Ah I remember this.
I ran into a similar issue with the background color property. The main problem is that the Tiled standard doesn't really specify defaults, and I wasn't sure where to 'cleanup' the data, so I ended up just not doing it because I forgot.

Ideally I'd rather have the user-facing data structures be easier to work with, so just like I did with the color, I think it makes sense to have a reasonable value filled in when it's missing from the underlying json/xml (meaning when it's nil).

I don't have time right now, but tomorrow I'll try and look at what the Tiled editor does with a missing probability (whether it treats it as 0, 1, or something else) and copy their behaviour.

[Zulu-Inuoe]

This is incredibly delayed. I apologize. But after looking at #14 , I think whatever comes out of #15 will be a better way to get 'equivalent to the Tiled editor' behaviour. So this fix makes perfect sense.

Thanks