object—an object.
type-specifier—any type specifier except values, or a type specifier list whose first element is either function or values.
environment—an environment object.
The default is nil
, denoting the null lexical environment
and the and current global environment.
generalized-boolean—a generalized boolean.
Returns true if object is of the type specified by type-specifier; otherwise, returns false.
A type-specifier of the form (satisfies fn)
is handled by applying the function fn
to object.
(typep
object '(array
type-specifier))
,
where type-specifier is not *
,
returns true if and only if object is an array
that could be the result
of supplying type-specifier
as the :element-type argument to make-array
.
(array *)
refers to all arrays
regardless of element type, while (array
type-specifier)
refers only to those arrays
that can result from giving type-specifier as the
:element-type argument to make-array
.
A similar interpretation applies to (simple-array
type-specifier)
and (vector
type-specifier)
.
See Section 15.1.2.1 (Array Upgrading).
(typep
object '(complex
type-specifier))
returns true for all complex numbers that can result from
giving numbers of type type-specifier
to the function complex
, plus all other complex numbers
of the same specialized representation.
Both the real and the imaginary parts of any such
complex number must satisfy:
(typep realpart 'type-specifier) (typep imagpart 'type-specifier)
See the function upgraded-complex-part-type.
(typep 12 'integer) → true (typep (1+ most-positive-fixnum) 'fixnum) → false (typep nil t) → true (typep nil nil) → false (typep 1 '(mod 2)) → true (typep #c(1 1) '(complex (eql 1))) → true ;; To understand this next example, you might need to refer to ;; Section 12.1.5.3 (Rule of Canonical Representation for Complex Rationals). (typep #c(0 0) '(complex (eql 0))) → false
Let Ax
and Ay
be two type specifiers that
denote different types, but for which
(upgraded-array-element-type 'Ax)
and
(upgraded-array-element-type 'Ay)
denote the same type. Notice that
(typep (make-array 0 :element-type 'Ax) '(array Ax)) → true (typep (make-array 0 :element-type 'Ay) '(array Ay)) → true (typep (make-array 0 :element-type 'Ax) '(array Ay)) → true (typep (make-array 0 :element-type 'Ay) '(array Ax)) → true
An error of type error
is signaled if type-specifier is values
,
or a type specifier list whose first element is either
function or values.
The consequences are undefined if the type-specifier is not a type specifier.
type-of, upgraded-array-element-type, upgraded-complex-part-type, Section 4.2.3 (Type Specifiers)
Implementations are encouraged to recognize and optimize the case of
(typep
x (the class
y))
,
since it does not involve any need for expansion
of deftype
information at runtime.