When working on the early stages of a console-based Python remake of the classic game ‘Snake’, someone submitted a patch to spawn food at random locations. The code defined a Food class which worked fine, but the logic behind it seemed a little weird.
I think we should delete the food once it’s been consumed, then create another one. However, this person simply moves the food to a new random location once it’s been consumed. While the latter seems illogical to me, it seems to do the exact same thing, maybe even more efficiently.
My question is: Would it be better to use the former logic, or the later, or am I simply nit-picking over nothing?
This all started at: https://bugs.launchpad.net/snakes-game/+bug/628180
Either is fine – within certain common-sense boundaries.
The latter approach will save re-allocating the object, so recycling it in this way will be more efficient – the gain is likely to be irrelevant in your particular example though unless heap fragmentation is a concern (e.g. on an embedded app with very limited RAM).
The danger with recycling is that the object may retain some vestige of its former state, so may not behave in the same manner as a new object would – in your case the logic is simple, so there is little danger, but with more complex objects this could become significant.
So in general I’d suggest the “create a new object” approach (it follows the principle of “least surprise”, and will be less likely to confuse other programmers who come to work on the code) unless there are performance implications (e.g. on an embedded application like a phone where you have very limited resources and don’t want a fragmented heap), in which case the “re-use an existing object” may be a smart solution.