Actually, I can be more helpful. ``nano-count`` returns a ``uint64_t`` so
you need 8 bytes.

In vm/os-genunix.cpp:

uint64_t nano_count() {
  struct timespec t;
  int ret = clock_gettime(CLOCK_MONOTONIC, &t);
  if (ret != 0)
    fatal_error("clock_gettime failed", 0);
  return (uint64_t)t.tv_sec * 1000000000 + t.tv_nsec;
}

On Fri, Jun 5, 2020 at 5:00 PM Doug Coleman <doug.cole...@gmail.com> wrote:

> As long as you can fully round-trip the integer, it doesn't matter how
> many bytes you use.
>
> nano-count dup 4 >be be> = .
> f
>
> nano-count dup 8 >be be> = .
> t
>
> nano-count dup 128 >be be> = .
> t
>
>
> ``log2 1 +`` will give you the required number of bits to store an
> integer. You will want to round up to a power of 8 bits or a power of two
> bytes.
>
> USE: math.bitwise
> nano-count dup dup log2 1 + bits =
>
> On Fri, Jun 5, 2020 at 4:44 PM Alexander Ilin <ajs...@yandex.ru> wrote:
>
>> Hello again!
>>
>>  My specific example is the following. I want to put the output of
>> `nano-count` into a `byte-array`, which is fed into a hash. The current
>> value of `nano-count` is one of the sources of randomness gathered from the
>> system and poured into the hash. To convert the integer value into a
>> `byte-array` there are `>le` and `>be`, but they require the number of
>> bytes as a parameter. The question is, what should I supply for the value
>> received from `nano-count`?
>>
>>  And the bigger question is, given an integer value, is there a way to
>> interrogate it about its byte size, i.e. the minimum number of bytes it
>> takes to hold the value without truncation and without leading zeroes:
>>
>>  Value -- MinSize
>>  0 -- 1
>>  255 -- 1
>>  256 -- 2
>>  65535 -- 2
>>  65536 -- 3
>>  etc.
>>
>>  I would expect such information to be available somewhere without doing
>> the power of two calculations in a loop.
>>
>> 23.03.2020, 05:41, "Doug Coleman" <doug.cole...@gmail.com>:
>>
>> For Factor, integers are either fixnum or bignum size. For C, you tell it
>> how many bytes it occupies according to the C header. Generally the sizes
>> are the same across platforms. If they aren't, you might need two different
>> STRUCT: declarations like in basis/unix/stat/linux/32/32.factor
>> and basis/unix/stat/linux/64/64.factor.
>>
>> The main point -- function signatures and struct declarations usually
>> handle the integer sizes and you shouldn't have to think much about it. Do
>> you have a specific example?
>>
>>
>>
>>
>> Earlier I wrote:
>>
>>  One more question. I want to convert an integer into a byte-array
>> containing its bytes. In my use case it was the return value of the
>> nano-count, but the question is general: how can I get the bytes of an
>> integer.
>>
>>  For floats there are primitives like float>bits and double>bits, and for
>> integers there is >le and >be, but for the latter two I need to specify the
>> size in bytes. Is there a way to ask an integer how many bytes it occupies?
>> Because from the documentation it's not clear at all how many bytes
>> nano-count would return, and it may vary depending on the current platform.
>> What am I missing?
>>
>> _______________________________________________
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>> Factor-talk@lists.sourceforge.net
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>>
>
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