Example: AVERAGE

Takes two numeric arguments and returns the mean.

> (defmacro average (num1 num2)

> (list '/ (list '+ (eval num1) (eval num2))

> 2) )

AVERAGE

> (macroexpand '(average 2 (* 5 4)))

(/ (+ 2 20))

T

> (average 2 (* 5 4))

11

Arguments to macros are not automatically evaluated, as they are in function calls. In this example, there is no advantage to using a macro.

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