type-of
type-of Function
Syntax:
type-of object → typespec
Arguments and Values:
object—an object.
typespec—a type specifier .
Description:
Returns a type specifier , typespec, for a type that has the object as an element. The typespec satisfies the following:
1. For any object that is an element of some built-in type:
a. the type returned is a recognizable subtype of that built-in type.
b. the type returned does not involve and, eql, member, not, or, satisfies, or values.
type-of2. For all objects, (typep object (type-of object)) returns true. Implicit in this is that type specifiers which are not valid for use with typep, such as the list form of the function type specifier , are never returned by type-of.
3. The type returned by type-of is always a recognizable subtype of the class returned by class-of. That is,
(subtypep (type-of object) (class-of object)) → true, true
4. For objects of metaclass structure-class or standard-class, and for conditions, type-of returns the proper name of the class returned by class-of if it has a proper name, and otherwise returns the class itself. In particular, for objects created by the constructor function of a structure defined with defstruct without a :type option, type-of returns the structure name; and for objects created by make-condition, the typespec is the name of the condition type.
5. For each of the types short-float, single-float, double-float, or long-float of which the object is an element, the typespec is a recognizable subtype of that type.
Examples:
(type-of ’a) → SYMBOL
(type-of ’(1 . 2))
→ CONS
<i><sup>or</sup>→</i> (CONS FIXNUM FIXNUM)
(type-of #c(0 1))
→ COMPLEX
<i><sup>or</sup>→</i> (COMPLEX INTEGER)
(defstruct temp-struct x y z) → TEMP-STRUCT
(type-of (make-temp-struct)) → TEMP-STRUCT
(type-of "abc")
→ STRING
<i><sup>or</sup>→</i> (STRING 3)
(subtypep (type-of "abc") ’string) → true, *true*
(type-of (expt 2 40))
→ BIGNUM
<i><sup>or</sup>→</i> INTEGER
<i><sup>or</sup>→</i> (INTEGER 1099511627776 1099511627776)
<i><sup>or</sup>→</i> SYSTEM::TWO-WORD-BIGNUM
<i><sup>or</sup>→</i> FIXNUM
(subtypep (type-of 112312) ’integer) → true, *true*
(defvar \*foo\* (make-array 5 :element-type t)) → \*FOO\*
(class-name (class-of \*foo\*)) → VECTOR
(type-of \*foo\*)
→ VECTOR
<i><sup>or</sup>→</i> (VECTOR T 5)
See Also:
array-element-type, class-of, defstruct, typecase, typep, Section 4.2 (Types)
Notes:
Implementors are encouraged to arrange for type-of to return a portable value.
Expanded Reference: type-of
TODO: Please contribute to this page by adding explanations and examples
(type-of )