Sources of bits for pract_test()

A source tells pract_test() where the bits to test come from. pract_raw() reads raw bytes, from a raw vector or a binary connection, in order. pract_fun() calls an R function for more bits each time the test needs them. pract_rng() draws from one of R's own generators, and pract_interleave() combines sources word by word.

Usage

pract_raw(x)

pract_fun(f, bits = 32)

Arguments

x

A raw vector, or a connection to read bytes from.

f

A function of one argument, n, returning n words of bits bits: an integer vector of length n when bits is 32, or a raw vector of n * bits / 8 bytes for any bits. Integers are taken as their 32-bit patterns, so NA is the word 0x80000000.

bits

The size in bits of the words f returns: 8, 16, 32 or 64. PractRand folds its tests to the word size; pract_raw() sources have no word size, as with PractRand's RNG_test stdin.

Value

An object of class zurngtest_source.

Details

A raw vector or connection that ends before the test does ends the run early; see pract_test(). A raw vector source can be used for several runs, each reading from the start. A connection that is not open is opened in binary mode for the run and closed after it, which destroys it, as readLines() does, so it serves one run; an open connection is read from where it is and left open.

See also

Other sources: pract_interleave(), pract_rng()

Examples

pract_raw(as.raw(sample(0:255, 1024, replace = TRUE)))
#> <zurngtest_source> raw vector of 1024 bytes

# R's own generator, as bytes
pract_fun(
  function(n) as.raw(sample.int(256L, n, replace = TRUE) - 1L),
  bits = 8
)
#> <zurngtest_source> function function(n) as.raw(sample.int(256L, n, replace = TRUE) - 1L), 8-bit words