PackedByteArray, Array slice end exclusive, rename PackedByteArray subarray to slice

[nathanfranke]

• slice end index is now exclusive
• Packed*Array::subarray is now Packed*Array::slice

func _ready() -> void:
	var array := PackedByteArray([0, 1, 2, 3, 4, 5, 6, 7])
	
	aprint(array.slice(0, 4))             ### 0, 1, 2, 3
	# Lines below would have crashed
	aprint(array.slice(4, 8))             ### 4, 5, 6, 7
	aprint(array.slice(0, array.size()))   ### 0, 1, 2, 3, 4, 5, 6, 7

func aprint(array: PackedByteArray) -> void:
	var s := String()
	for i in array:
		s += ", " + str(i)
	print(s.substr(2))

[aaronfranke]

I'm curious why it was inclusive in the first place. This was added in #31172, pinging @creikey.

[creikey]

@aaronfranke I don't remember specifically why I did that in the first place, I should've written that down in the PR, but my guess is that it was because the pool byte array was already inclusive.

[nathanfranke]

Updated to new master branch. Should work completely fine but additional testing may be needed

[nathanfranke]

I am assuming I have to rebase this since PoolByteArray changed to PackedByteArray. I should be able to do it tonight

Edit: Done with this!

[creikey]

I remember why I made the array slice inclusive on both ends now, it's to make it so that when the p_step parameter is negative ( you're going backwards in the array ) you can use the array's size on the end bound and have it still work, it's symmetrical going forwards and backwards with the array indexes.

In hindsight, it might be more clear to the user if the first index and last index were switched around when p_step is negative, such that it starts at the end index and ends at the first index ( I think the behavior is opposite that right now ).

[nathanfranke]

I updated this to master. I need to understand exactly what the expected behaviour should be, especially with negative steps.

Examples of current behaviour:

var a = [0, 1, 2, 3, 4, 5, 6, 7]

print(a.slice(0, 4)) # [0, 1, 2, 3]
print(a.slice(4, 8, -1)) # []
print(a.slice(8, 0, -1)) # [7, 6, 5, 4, 3, 2, 1, 0]
print(a.slice(-1, 0, -1)) # [6, 5, 4, 3, 2, 1, 0]

[nathanfranke]

Rebased again. Added documentation for PackedColorArray, PackedFloat32Array, PackedFloat64Array, PackedInt32Array, PackedInt64Array, PackedStringArray, PackedVector2Array, PackedVector3Array

[Anutrix]

Requesting rebase.

[akien-mga]

Makes sense to me 👍

[mhilbrunner]

PR meeting: makes sense, approved :)

[akien-mga]

Thanks!

[akien-mga]

See #56661 for a follow-up discussion on the behavior for negative end.