I am just learning Julia...
I was quite shocked today to learn that Julia does *not*
initialize allocated storage (e.g. to 0 or some default value).
E.g. the code
A = Array(Int64,5)
println(A[1])
has unpredictable behavior, may disclose information from
other modules, etc.
This is really quite unacceptable in a modern programming
language; it is as bad as not checking array reads for out-of-bounds
indices.
Google for "uninitialized security" to find numerous instances
of security violations and unreliability problems caused by the
use of uninitialized variables, and numerous security advisories
warning of problems caused by the (perhaps inadvertent) use
of uninitialized variables.
You can't design a programming language today under the naive
assumption that code in that language won't be used in highly
critical applications or won't be under adversarial attack.
You can't reasonably ask all programmers to properly initialize
their allocated storage manually any more than you can ask them
to test all indices before accessing an array manually; these are
things that a high-level language should do for you.
The default non-initialization of allocated storage is a
mis-feature that should absolutely be fixed.
There is no efficiency argument here in favor of uninitialized storage
that can outweigh the security and reliability disadvantages...
Cheers,
Ron Rivest
