# (map_bytes_to_double bytes)
# Map the series of byte values (numbers in the range 0 to 255) into a double-
# precision floating point value.
#
# Test vectors:
# [0 0 0 0 0 0 0]               => 0
# [255 255 255 255 255 255 63]  => 0.25
# [255 255 255 255 255 255 127] => 0.5
# [255 255 255 255 255 255 191] => 0.75
# [255 255 255 255 255 255 255] => 1

\map_bytes_to_double=(fold (\x\b / (+ x b) 256) 0)

# Get a random double-precision floating point value in the range 0 to 1
# inclusive.
\\random_double=
	(
	\bytes=(map ord; str_bytes; random_bytes 7)
	map_bytes_to_double bytes
	)