Re:Why Clojure? (2010)
by junke on Friday December 30, 2016 @10:49AM
(#13284906)
No, I was talking about (Common) Lisp's generic functions (http://clhs.lisp.se/Body/m_defgen.htm). I realize I did not give enough context. Define a generic function:
Specialize it on one or multiple arguments:
But you can use it like a function:
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Ah my bad! :)
These look very much like Clojure's protocols and multi-methods.
Yes, more like multi-methods, except for standard qualifiers (:around, :before, ...) and user-defined ones. OTOH, Clojure allows you to define a custom dispatch function.
Ah yes, Clojure has no first-class support for aspects. Its easy enough to monkey patch definitions for the rare case when its needed.
Most of the time however I try to avoid aspects as they introduce hidden behaviour in existing functions, which can be hard to reason about at scale, especially with more than a few developers.
I use them all the time. It's a great way to separate responsibilities.
I prefer function composition for that when possible :)
Aspects I feel are more useful when you want to modify the behaviour of existing code you don't own.
Maybe if I had easy access to them I'd find more use cases :)