《通链参考手册》


Accessor FDEFINITION

●语法设定:

fdefinition function-name => definition

(setf (fdefinition function-name) new-definition)

●参数和值:

function-name---a function name. In the non-setf case, the name must be fbound in the global environment.

definition---Current global function definition named by function-name.

new-definition---a function.

●详情:

fdefinition accesses the current global function definition named by function-name. The definition may be a function or may be an object representing a special form or macro. The value returned by fdefinition when fboundp returns true but the function-name denotes a macro or special form is not well-defined, but fdefinition does not signal an error.

●例子: None.

●副作用: None.

●受制于: 无。

●例外情况:

Should signal an error of type type-error if function-name is not a function name.

An error of type undefined-function is signaled in the non-setf case if function-name is not fbound.

●更多信息:

fboundp, fmakunbound, macro-function, special-operator-p, symbol-function

●说明:

fdefinition cannot access the value of a lexical function name produced by flet or labels; it can access only the global function value.

setf can be used with fdefinition to replace a global function definition when the function-name's function definition does not represent a special form. setf of fdefinition requires a function as the new value. It is an error to set the fdefinition of a function-name to a symbol, a list, or the value returned by fdefinition on the name of a macro or special form.


X3J13设计清单非标准部分,可查下面章节:


◇首页 § ◎章节目录 § □内容索引 § ○符号索引 § △术语表 § ※设计草案