+1 for some- and some-.
I use this all the time in my coding. They used to be -? and -? in
clojure.core.incubator, so I'm extremely happy that they finally made their
way into core proper.
On Saturday, March 23, 2013 7:25:00 PM UTC-4, Evan Gamble wrote:
The let? macro addresses such
I've recently had a need for something like that in my own code. The
real solution to that problem in the functional programming world is
known as the maybe monad. Since I just needed a quick and dirty
solution and I have not wrapped my head around monads yet, here's what
I did :
(defmacro maybe-
Your maybe- does almost the same thing as Clojure 1.5's some- but without
support for naked fns (like `(some- 1 inc)`). It also evaluates each
step but the last twice (once for the `if`, once when inserted after
`op`).
If you don't want to switch to some-, I'd recommend you use when-let to
avoid
The let? macro addresses such
situations: https://github.com/egamble/let-else
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Hi Clojurians,
I'm relatively new to the language and am trying to get used to its idioms.
One thing I'm accustomed to doing in things like java and C# is checking
values for validity and then bailing out early if they don't make sense.
For example, without this idiom in java you might do:
2013/3/23 Russell Mull russell.m...@gmail.com
Which leads me to my question: does such a construct already exist? Or
perhaps am I doing it wrong? I've googled around for this, but I'm not
exactly sure what it's called.
http://clojuredocs.org/clojure_core/clojure.core/if-let (and its close
You can get quite a long way with just if-let and and or to express
the bailout logic.
Examples I find myself using all the time:
;; fallback / default values
(or (maybe-make-value) (make-fallback-value) (error this shouldn't
happen!))
;; bailout with nil return (assumes you are running
