On Jul 27, 5:50 am, Feng Shen <shen...@gmail.com> wrote:
> Clojure core.clj has a macro when-let,
> I am wondering how to write a macro `when-lets`
>
> (when-lets [symbol-1 test-1
> symbol-2 test-2
> ...
> ]
> body
> )
>
> body only get evaluated when (and test-1 test-2 ....)
> I am thinking about it, anybody has any clue?
(defmacro when-lets [tests & body]
(reduce (fn [body test]
`(when-let ~(vec test)
~body))
`(do ~@body)
(partition 2 (reverse tests))))
This would be cleaner if we had foldr in the language already - I find
myself wanting it quite often for macros like this.
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