You can use record's positional constructor:
user> (defrecord R [a])
user.R
user> ((find-var (symbol "user/->R")) 5)
#user.R{:a 5}
JW
On Wednesday, August 6, 2014 12:51:11 PM UTC+2, Ambrose Bonnaire-Sergeant
wrote:
>
> Hi Colin,
>
> If you must call the Java constructor, you need reflection.
>
> user=> (defrecord B [c])
> user.B
> user=> (def s "user.B")
> #'user/s
> user=> (.newInstance (first (.getDeclaredConstructors (Class/forName s)))
> (object-array [1]))
> #user.B{:c 1}
>
> Thanks,
> Ambrose
>
>
> On Wed, Aug 6, 2014 at 6:37 PM, Colin Yates <colin...@gmail.com
> <javascript:>> wrote:
>
>> Hi,
>>
>> tldr; if I have a (defrecord MyRecord) in ns a.b.c and I have a string
>> "a.b.c.MyRecord" how I can invoke (a.b.c.MyRecord.) (or (new
>> a.b.c.MyRecord)?
>>
>> I thought this was going to be as simple as (defn cfn "a.b.c.MyRecord")
>> ((symbol cfn).) but that throws an ArityException: wrong number of args (0)
>> passed to Symbol. I
>>
>> I have a protocol with a number of implementations. Each installation
>> will have a single implementation and will chose one based on an
>> environment variable. At runtime I need to look at that environment
>> variable which defines the fully qualified implementation of a protocol. I
>> then need to instantiate that record.
>>
>> Architecturally equivalent to a simple plugin system. I could alias them
>> all but that requires knowing about all the implementations which is a
>> no-go.
>>
>> This is where I feel the pain of not having OSGi :).
>>
>> Thanks all!
>>
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