In LISP, a named macro is defined using another macro named defmacro. Syntax for defining a macro is −
(defmacro macro-name (parameter-list))
"Optional documentation string."
body-form​
The macro definition consists of the name of the macro, a parameter list, an optional documentation string, and a body of Lisp expressions that defines the job to be performed by the macro.
Example : Let us write a simple macro named
setTo10, which will take a number and set its value to 10.
Create new source code file named
main.lisp and type the following code in it.
(defmacro setTo10(num)
(setq num 10)(print num))
(setq x 25)
(print x)
(setTo10 x)​
When you click the Execute button, or type
Ctrl+E, LISP executes it immediately and the result returned is :
25
10​
