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ANSI Common Lisp  5 Data and Control Flow 5.3 Dictionary of Data and Control Flow
- Syntax:
-
fboundp
name
 generalized-boolean
- Pronunciation:
-
[ 'ef'baündpê ]
- Arguments and Values:
-
name - a function name.
generalized-boolean - a generalized boolean.
- Description:
-
Returns true if name is fbound; otherwise, returns false.
- Examples:
-
(fboundp 'car) true
(fboundp 'nth-value) false
(fboundp 'with-open-file) true
(fboundp 'unwind-protect) true
(defun my-function (x) x) MY-FUNCTION
(fboundp 'my-function) true
(let ((saved-definition (symbol-function 'my-function)))
(unwind-protect (progn (fmakunbound 'my-function)
(fboundp 'my-function))
(setf (symbol-function 'my-function) saved-definition)))
false
(fboundp 'my-function) true
(defmacro my-macro (x) `',x) MY-MACRO
(fboundp 'my-macro) true
(fmakunbound 'my-function) MY-FUNCTION
(fboundp 'my-function) false
(flet ((my-function (x) x))
(fboundp 'my-function)) false
- Exceptional Situations:
-
Should signal an error of type type-error if name is not a function name.
- See Also:
-
symbol-function, fmakunbound, fdefinition
- Notes:
-
It is permissible to call symbol-function on any symbol
that is fbound.
fboundp is sometimes used to "guard"
an access to the function cell, as in:
(if (fboundp x) (symbol-function x))
Defining a setf expander F does not cause the setf function
(setf F) to become defined.
- Allegro CL Implementation Details:
-
None.
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