Char.Ascii(3)                    OCaml library                   Char.Ascii(3)

NAME
       Char.Ascii - ASCII character set support.

Module
       Module   Char.Ascii

Documentation
       Module Ascii
        : sig end


       ASCII character set support.

       These functions give meaning to the integers [ 0x00 ; 0x7F ] of the
       ASCII character set.

       Since the UTF-8 encoding of Unicode has the same encoding and character
       semantics (U+0000 to U+001F) for these bytes, the functions can be
       safely used on elements of UTF-8 encoded string and bytes values.
       However the functions only deal with ASCII related matters. For example
       the notion of Unicode whitespace is much larger than the ASCII
       whitespace determined by Char.Ascii.is_white .


       Since 5.4







   Characters
       val min : char


       min is '\x00' .



       val max : char


       max is '\x7F' .




   Predicates
       val is_valid : char -> bool


       is_valid c is true if and only if c is an ASCII character, that is a
       byte in the range [ Char.Ascii.min ; Char.Ascii.max ].



       val is_upper : char -> bool


       is_upper c is true if and only if c is an ASCII uppercase letter 'A' to
       'Z' , that is a byte in the range [ 0x41 ; 0x5A ].



       val is_lower : char -> bool


       is_lower c is true if and only if c is an ASCII lowercase letter 'a' to
       'z' , that is a byte in the range [ 0x61 ; 0x7A ].



       val is_letter : char -> bool


       is_letter c is Char.Ascii.is_lower c || Char.Ascii.is_upper c .



       val is_alphanum : char -> bool


       is_alphanum c is Char.Ascii.is_letter c || Char.Ascii.is_digit c .



       val is_white : char -> bool


       is_white c is true if and only if c is an ASCII white space character,
       that is one of tab '\t' ( 0x09 ), newline '\n' ( 0x0A ), vertical tab (
       0x0B ), form feed ( 0x0C ), carriage return '\r' ( 0x0D ) or space ' '
       ( 0x20 ),



       val is_blank : char -> bool


       is_blank c is true if and only if c is an ASCII blank character, that
       is either space ' ' ( 0x20 ) or tab '\t' ( 0x09 ).



       val is_graphic : char -> bool


       is_graphic c is true if and only if c is an ASCII graphic character,
       that is a byte in the range [ 0x21 ; 0x7E ].



       val is_print : char -> bool


       is_print c is Char.Ascii.is_graphic c || c = ' ' .



       val is_control : char -> bool


       is_control c is true if and only if c is an ASCII control character,
       that is a byte in the range [ 0x00 ; 0x1F ] or 0x7F .




   Decimal digits
       val is_digit : char -> bool


       is_digit c is true if and only if c is an ASCII decimal digit '0' to
       '9' , that is a byte in the range [ 0x30 ; 0x39 ].



       val digit_to_int : char -> int


       digit_to_int c is the numerical value of a digit that satisfies
       Char.Ascii.is_digit . Raises Invalid_argument if Char.Ascii.is_digit c
       is false .



       val digit_of_int : int -> char


       digit_of_int n is an ASCII decimal digit for the decimal value abs (n
       mod 10) .




   Hexadecimal digits
       val is_hex_digit : char -> bool


       is_hex_digit c is true if and only if c is an ASCII hexadecimal digit
       '0' to '9' , 'a' to 'f' or 'A' to 'F' , that is a byte in one of the
       ranges [ 0x30 ; 0x39 ], [ 0x41 ; 0x46 ], [ 0x61 ; 0x66 ].



       val hex_digit_to_int : char -> int


       hex_digit_to_int c is the numerical value of a digit that satisfies
       Char.Ascii.is_hex_digit . Raises Invalid_argument if
       Char.Ascii.is_hex_digit c is false .



       val lower_hex_digit_of_int : int -> char


       lower_hex_digit_of_int n is a lowercase ASCII hexadecimal digit for the
       hexadecimal value abs (n mod 16) .



       val upper_hex_digit_of_int : int -> char


       upper_hex_digit_of_int n is an uppercase ASCII hexadecimal digit for
       the hexadecimal value abs (n mod 16) .




   Casing transforms
       val uppercase : char -> char


       uppercase c is c with ASCII characters 'a' to 'z' respectively mapped
       to uppercase characters 'A' to 'Z' . Other characters are left
       untouched.



       val lowercase : char -> char


       lowercase c is c with ASCII characters 'A' to 'Z' respectively mapped
       to lowercase characters 'a' to 'z' . Other characters are left
       untouched.



OCamldoc                          2026-06-22                     Char.Ascii(3)