Character operations.
Return the ASCII code of the argument.
Return the character with the given ASCII code or None
is the argument is outside
the range 0 to 255.
Return the character with the given ASCII code. Raise Failure
if the argument is
outside 0 to 255.
Return a string representing the given character, with special characters escaped following the lexical conventions of Objective Caml.
'0' - '9'
'a' - 'z'
'A' - 'Z'
'a' - 'z' or 'A' - 'Z'
'a' - 'z' or 'A' - 'Z' or '0' - '9'
' ' - '~'
' ' or '\t' or '\r' or '\n'
Return Some i
if is_digit c
and None
otherwise.
Return i
if is_digit c
. Raises Failure
otherwise.