How to defun a function within a defun?
For example, I pass the function name to another func开发者_如何学Pythontion
(personal-function 'func-name '(attr1 attr2 ...))
and what I want to do is
(defun personal-function (func-name)
(defun func-name '(attr1 attr2 ...) (dosomething)))
However, it said I can't defun
with a symbol... What should I do?
Use
(setf (symbol-function my-symbol) some-function)
create a new function with
(compile nil (list 'lambda args body))
where args and body have meaningful values.
Solve it as follows:
e.g1
(defun create-function(a1)
(defun plus-function(x) (+ x a1)))
(create-function 2) -> PLUS-FUNCTION
(plus-function 3) ->5
e.g2
(setf (symbol-function 'printx) #'(lambda (x) (print x)))
(printx '(1 2 3)) -> (1 2 3)
Previously I also had the same problem when I defined the function.
Example:
(defun test-function(fn)
(defun fn ((lambda() (print "aaa")))))
After I run
(test-function 'aaafunction)
The evaluation result is
FN
It does not return a function named "aaafunction"...
To the person who downvote my answer: We are newbies of Lisp, but we are working hard to learn knowledge, and you are not so respectful.
You could use a lambda
http://www.n-a-n-o.com/lisp/cmucl-tutorials/LISP-tutorial-21.html
If you're trying to make a new globally-accessible function inside a function, I don't think the language's grammar allows for that. If you create a lambda, you can initialize a variable to this lambda value and pass the variable around to your functions. In Common LISP, you can call (functionp x) to determine if a variable is a function before you try to call it.
I use defmacros for metaprogramming, for example, this emacs lisp example.
Using a macro will be a good choice. such as (defmacro personal-function (func-name) `(defun ,func-name '(attr1 attr2 ...) (dosomething))) please have a try, hope that helps you.
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