Hi,
On 2 Nov., 08:14, Mike Meyer wrote:
> This only happens if the rest argument destructuring is a hash map -
> if I use a vector or a symbol there, then the values don't get turned
> into a map. Can't that same mechanism be used in the case where some
> non-rest argument is a hash-map trying t
On Mon, 1 Nov 2010 23:41:47 -0700 (PDT)
Meikel Brandmeyer wrote:
> Hi,
>
> On 2 Nov., 03:25, Mike K wrote:
>
> > (print-value-a [:b 7 :a 3])
> > ; actually prints nil
>
> You have to use apply. (apply print-value-a [:b 7 :a 3]).
>
> Furthermore: how could (let [{a :a} [:b 7 :a 3]] [a]) possi
Hi,
On 2 Nov., 07:41, Meikel Brandmeyer wrote:
> Hi,
>
> On 2 Nov., 03:25, Mike K wrote:
> The map destructuring in the defn is a special case of defn, not
> destructuring itself.
>
> (defn foo [& {:keys [a b]}] ...)
>
> is equivalent to
>
> (defn foo [& options#] (let [{:keys [a b]} (apply has
Hi,
On 2 Nov., 03:25, Mike K wrote:
> (print-value-a [:b 7 :a 3])
> ; actually prints nil
You have to use apply. (apply print-value-a [:b 7 :a 3]).
Furthermore: how could (let [{a :a} [:b 7 :a 3]] [a]) possibly work?
Vectors are indexed by integers.
user=> (let [{a :a} [:b 7 :a 3]] [a])
[nil]
On Mon, 1 Nov 2010 19:25:59 -0700 (PDT)
Mike K wrote:
> This question is a bit abstruse, so please bear with me :-)
[elided]
> So this can't be how it works, but I don't know how else to interpret
> the documentation. Is this a special case meaning "if there are
> optional arguments AND they are
This question is a bit abstruse, so please bear with me :-)
Here is an example of a function with named arguments and default
values from the book "The Joy of Clojure". It uses optional arguments
(via &) and map destructuring.
(defn slope
[& {:keys [p1 p2] :or {p1 [0 0] p2 [1 1]}}]
(float (
