Another alternative way, added in Clojure 1.5, can be nice if you have a
lot of conditionally-added key-value pairs:
(defn create-map []
> (cond-> {:base :map}
> (pred1) (assoc :extra-key1 value)
> (pred2) (assoc :extra-key2 value)
> (pred3) (assoc :extra-key3 value)
> (pred4) (assoc :extra-key4 value)))
On Thu, Feb 21, 2013 at 7:41 AM, Alex Baranosky <
alexander.barano...@gmail.com> wrote:
> I'd often just write it like this:
>
> (defn create-map []
>> (merge {:foo "a"
>> :bar "b"
>> ... many more keys}
>> (when (some-condition-true)
>> {:extra-key value)))
>
>
> Alex
>
>
> On Thu, Feb 21, 2013 at 7:27 AM, Ryan <arekand...@gmail.com> wrote:
>
>> Thanks Meikel for your reply.
>>
>> It wasn't clear on my example, but I wish to use *merge *inside my
>> create-map function. Do you think I should bind my hash-map to a let
>> variable first and then apply merge, or do you have another proposal? What
>> i mean is this:
>>
>> (defn create-key-value [value]
>>
>> (when (some-condition-true) {:extra-key value))
>>
>>
>> (defn create-map []
>>> (let [my-map {:foo "a" :bar "b"}]
>>> (merge my-map (create-key-value "some-value")))
>>
>>
>> Is the above "clojurish" or is there a better way? For example if the
>> my-map was a big hash-map, and not with just two pairs, wouldn't it be ugly
>> with the above way? or..it's just fine and no better way is possible?
>>
>> Ryan
>>
>> On Thursday, February 21, 2013 5:02:21 PM UTC+2, Meikel Brandmeyer
>> (kotarak) wrote:
>>>
>>> Hi,
>>>
>>> merge works with nil. So (merge (create-map) (create-key-value
>>> "some-value")) should work as you intend with the functions as they are
>>> defined now.
>>>
>>> Kind regards
>>> Meikel
>>>
>>> --
>> --
>> You received this message because you are subscribed to the Google
>> Groups "Clojure" group.
>> To post to this group, send email to clojure@googlegroups.com
>> Note that posts from new members are moderated - please be patient with
>> your first post.
>> To unsubscribe from this group, send email to
>> clojure+unsubscr...@googlegroups.com
>> For more options, visit this group at
>> http://groups.google.com/group/clojure?hl=en
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "Clojure" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to clojure+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>
>
>
--
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
