78c5704f34
Works fine either way - this is just since underscores are required in filenames for real projects, so it's something good for folks to get used to.
42 lines
1.1 KiB
Clojure
42 lines
1.1 KiB
Clojure
(defmacro hello [x]
|
|
(str "Hello, " x))
|
|
|
|
(defmacro infix [form]
|
|
(list (second form) (first form) (nth form 2)))
|
|
|
|
(defmacro infix-better [form]
|
|
`(~(second form) ; Note the syntax-quote (`) and unquote (~) characters!
|
|
__
|
|
__ ))
|
|
|
|
(defmacro r-infix [form]
|
|
(cond (not (seq? form))
|
|
__
|
|
(= 1 (count form))
|
|
`(r-infix ~(first form))
|
|
:else
|
|
(let [operator (second form)
|
|
first-arg (first form)
|
|
others __]
|
|
`(~operator
|
|
(r-infix ~first-arg)
|
|
(r-infix ~others)))))
|
|
|
|
(meditations
|
|
"Macros are like functions created at compile time"
|
|
(= __ (hello "Macros!"))
|
|
|
|
"Can I haz some infix?"
|
|
(= __ (infix (9 + 1)))
|
|
|
|
"Remember, these are nothing but code transformations"
|
|
(= __ (macroexpand '(infix (9 + 1))))
|
|
|
|
"You can do better than that, hand crafting ftw!"
|
|
(= __ (macroexpand '(infix-better (10 * 2))))
|
|
|
|
"Things dont always work as you would like them to... "
|
|
(= __ (macroexpand '(infix-better ( 10 + (2 * 3)))))
|
|
|
|
"Really, you dont understand recursion until you understand recursion"
|
|
(= 36 (r-infix (10 + (2 * 3) + (4 * 5)))))
|