4.1. Types

4.1. Types
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4.1. Types [sec_4-2]

4.1.1. Type Specifiers

4.1.1. Type Specifiers [sec_4-2-3]

The general form of the COMPLEX type specifier is (COMPLEX type-of-real-part type-of-imaginary-part). The type specifier (COMPLEX type) is equivalent to (COMPLEX type type).

DEFTYPE lambda lists are subject to destructuring (nested lambda lists are allowed, as in DEFMACRO) and may contain a &WHOLE marker, but not an &ENVIRONMENT marker.

Function (EXT:TYPE-EXPAND type &OPTIONAL once-p). If type is a user-defined type specifier this will expand it recursively until it is no longer a user-defined type (unless once-p is supplied and non-NIL). Two values are returned - the expansion and an indicator (T or NIL) of whether the original type was a user-defined type specifier.

The possible results of TYPE-OF

CONS
SYMBOL, NULL, BOOLEAN, KEYWORD
BIT, (INTEGER 0 #.MOST-POSITIVE-FIXNUM), (INTEGER #.MOST-NEGATIVE-FIXNUM (0)), (INTEGER (#.MOST-POSITIVE-FIXNUM)), (INTEGER * (#.MOST-NEGATIVE-FIXNUM))
RATIONAL, SHORT-FLOAT, SINGLE-FLOAT, DOUBLE-FLOAT, LONG-FLOAT, COMPLEX
CHARACTER, BASE-CHAR, STANDARD-CHAR
(ARRAY element-type dimensions), (SIMPLE-ARRAY element-type dimensions)
(VECTOR T size), (SIMPLE-VECTOR size)
(STRING size), (SIMPLE-STRING size)
(BASE-STRING size), (SIMPLE-BASE-STRING size)
(BIT-VECTOR size), (SIMPLE-BIT-VECTOR size)
FUNCTION, COMPILED-FUNCTION, STANDARD-GENERIC-FUNCTION
STREAM, FILE-STREAM, SYNONYM-STREAM, BROADCAST-STREAM, CONCATENATED-STREAM, TWO-WAY-STREAM, ECHO-STREAM, STRING-STREAM
PACKAGE, HASH-TABLE, READTABLE, PATHNAME, LOGICAL-PATHNAME, RANDOM-STATE, BYTE
SPECIAL-OPERATOR, LOAD-TIME-EVAL, SYMBOL-MACRO, GLOBAL-SYMBOL-MACRO, EXT:ENCODING, FFI:FOREIGN-POINTER, FFI:FOREIGN-ADDRESS, FFI:FOREIGN-VARIABLE, FFI:FOREIGN-FUNCTION
EXT:WEAK-POINTER, EXT:WEAK-LIST, EXT:WEAK-AND-RELATION, EXT:WEAK-OR-RELATION, EXT:WEAK-MAPPING, EXT:WEAK-AND-MAPPING, EXT:WEAK-OR-MAPPING, EXT:WEAK-ALIST, READ-LABEL, FRAME-POINTER, SYSTEM-INTERNAL
ADDRESS (should not occur)
any other SYMBOL (structure types or CLOS classes)
a class object (CLOS classes without a proper name)

Function COERCE. FIXNUM is not a character designator in [ANSI CL standard], although CODE-CHAR provides an obvious venue to COERCE a FIXNUM to a CHARACTER. When CUSTOM:*COERCE-FIXNUM-CHAR-ANSI* is NIL, CLISP COERCEs FIXNUMs to CHARACTERs via CODE-CHAR. When CUSTOM:*COERCE-FIXNUM-CHAR-ANSI* is non-NIL, FIXNUMs cannot be COERCEd to CHARACTERs.