A reference class for storing and accessing matrix-like data stored on disk
in files containing only characters (digits) separated by a character.
Usage
mmapchar(file, code)
Arguments
file
Path of the file.
code
Integer vector of size 256 to access integers instead of
rawToChar(as.raw(0:255), multiple = TRUE).
See mmapcharr:::CODE_012 and mmapcharr:::CODE_DIGITS.