Introduction to Characters (original) (raw)
ANSI Common Lisp 
13 Characters 13.1 Character Concepts
13.1.1 Introduction to Characters
A character is an object that represents a unitary token (e.g., a letter, a special symbol, or a "control character") in an aggregate quantity of text (e.g., a string or a text stream).
Common Lisp allows an implementation to provide support for international language characters as well as characters used in specialized arenas (e.g., mathematics).
The following figures contain lists of defined names applicable to characters.
The next figure lists some defined names relating to character attributes and character predicates.
Character defined names -- 1
| alpha-char-p | char-not-equal | char> |
|---|---|---|
| alphanumericp | char-not-greaterp | char>= |
| both-case-p | char-not-lessp | digit-char-p |
| char-code-limit | char/= | graphic-char-p |
| char-equal | char< | lower-case-p |
| char-greaterp | char<= | standard-char-p |
| char-lessp | char= | upper-case-p |
The next figure lists some character construction and conversion defined names.
Character defined names -- 2
| char-code | char-name | code-char |
|---|---|---|
| char-downcase | char-upcase | digit-char |
| char-int | character | name-char |