There might be a reason to write (apply f coll seqable) in a situation
in which f might be conj, though.
On Sat, Nov 3, 2012 at 4:25 PM, Alan Malloy <a...@malloys.org> wrote:
> There is never a reason to write (apply conj ...). Instead, use `into`,
> which does the same thing but faster and with fewer characters.
>
>
> On Saturday, November 3, 2012 3:27:24 PM UTC-7, CGAT wrote:
>>
>> It would be nice if clojure.core/conj had a unary implementation
>>
>> ([coll] coll)
>>
>> The motivating use case is when one is conjoining sequences of
>> items to a collection all at once:
>>
>> (apply conj coll seqable)
>>
>> such as (apply conj #{1 2 3} [2 4 6 8 10]).
>> Currently (1.4.0), this will raise an arity exception
>> if the seqable object is empty:
>>
>> (apply conj #{1 2 3} [])
>>
>> necessitating an awkward empty? check when,
>> for instance, the sequence is computed or passed in.
>>
>> It seems to me that making unary conj the identity is both
>> a natural interpretation and essentially cost free, while
>> making this use case much more convenient.
>> Moreover, it is consistent with clojure.core/disj for sets
>> which does act like this
>>
>> (apply disj #{1 2 3} []) -> #{1 2 3}
>>
>> and has an identity unary implementation.
>>
>> Comments?
>>
>>
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