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character

character System Class

Class Precedence List:

character, t

Description:

A character is an object that represents a unitary token in an aggregate quantity of text; see Section 13.1 (Character Concepts).

The types base-char and extended-char form an exhaustive partition of the type character.

See Also:

Section 13.1 (Character Concepts), Section 2.4.8.1 (Sharpsign Backslash), Section 22.1.3.2 (Printing Characters)

Expanded Reference: character (System Class)​

The character type​

character is the system class for all character objects. Every character object is of type character.

(typep #\a 'character)
=> T
(typep #\Space 'character)
=> T
(typep #\Newline 'character)
=> T
(typep "a" 'character)
=> NIL
(typep 65 'character)
=> NIL

Type hierarchy​

The character type has two subtypes that form an exhaustive partition: base-char and extended-char. Every character is either a base character or an extended character, but not both.

(subtypep 'base-char 'character)
=> T
=> T
(subtypep 'extended-char 'character)
=> T
=> T
(subtypep 'standard-char 'character)
=> T
=> T

Using character as a type specifier​

The character type can be used in declarations, type checks, and as an array element type.

(let ((ch #\x))
  (declare (type character ch))
  (characterp ch))
=> T

(make-array 5 :element-type 'character :initial-element #\x)
=> "xxxxx"

Class precedence list​

The class precedence list for character is: character, t.

(typep #\a 't)
=> T
(typep #\a 'character)
=> T