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A comment on Why Lisp?. Parent comment

Re:Why Lisp? by ufo on Thursday May 07, 2015 @08:24PM (#9509315)
You pass a lambda that returns the debug message. With javascripty syntax:

    debug( function(){ return "my expensive log message" })
BTW, if your language is lazily evaluated (like Haskell) then you don't need to do this because arguments will only ve evaluated when they are needed.
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Re:Why Lisp? by MichaelGG on Thursday May 07, 2015 @10:05PM (#9509636)
The downside there is you can still end up allocating a closure. Whereas an expanded macro shouldn't cost anything. (A sufficiently smart compiler might be able to optimize the closure allocation.)
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Re:Why Lisp? by FeepingCreature on Friday May 08, 2015 @03:27AM (#9510403)
A sufficiently modern language (like, saaaaay, D2) could also give you a type like "closure you don't intend to escape" (let's call this a "scoped closure", or if you will, "scope string delegate()"), and eschew allocation entirely without requiring optimization.
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