Extend your language: Difference between revisions

=={{header|Fennel}}==

<lang fennel>;; Fennel, being a Lisp, provides a way to define macros for new syntax.

;; The "`" and "," characters are used to construct a template for the macro.

(macro if2 [cond1 cond2 both first second none]

`(if ,cond1

(if ,cond2 ,both ,first)

(if ,cond2 ,second ,none)))

(fn test-if2 [x y]

(if2 x y

(print "both")

(print "first")

(print "second")

(print "none")))

(test-if2 true true) ;"both"

(test-if2 true false) ;"first"

(test-if2 false true) ;"second"

(test-if2 false false) ;"none"</lang>