bug#6878: bool-vectors of length 0 signal error when aref/aset the 0th element

[Andreas Schwab]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> Maybe, but this is not what the manual has to say of the particular type of
>>> array that is a bool-vector, again (note the "must"):
>>> ,---- (info "(elisp)Bool-Vector Type")
>>> | "A "bool-vector" is a one-dimensional array of elements that must be `t'
>>> | or `nil'."
>> All elements of (make-bool-vector 0 t) are either t or nil.
>
> Indeed, this is trivially (and vacuously) true.  Actually, we can even
> say that all elements of a 0-length vector (bool or not) are both nil
> and t at the same time.

As long as you don't look at them ;-)

Andreas.

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Andreas Schwab, schwab@linux-m68k.org
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