Why do you want to do this? It's possible that it would improve
performance if you generated loads of these records, but you would
have to effectively compile your whole program at runtime in order to
have the static type information needed to get the improved
performance. Most of the time someone wants to do this it's some sort
of misguided OOP or "safety" feature that they want to control what's
in their hashmaps, and in those cases the answer is "well stop putting
stuff into your hashmaps if you don't want it getting there".
On Dec 18, 11:56 am, Bill Robertson <billrobertso...@gmail.com> wrote:
> I'm trying to define records based on meta data read in at runtime,
> and I'm attempting to write a function that extracts name and attrs
> and passes them to defrecord, but I don't understand how to
> dynamically create the symbol for the record name.
>
> e.g.
>
> user=> (defrecord (symbol "foo" "bar") [a b])
> java.lang.ClassCastException: clojure.lang.PersistentList cannot be
> cast to clojure.lang.Symbol (NO_SOURCE_FILE:5)
>
> Attempting to define fields in any way that I can guess at fail.
>
> e.g.
>
> user=> (def fields [(symbol "a")])
> #'user/fields
> user=> (defrecord foo fields)
> IllegalArgumentException Don't know how to create ISeq from:
> clojure.lang.Symbol clojure.lang.RT.seqFrom (RT.java:487)
> user=> (defrecord foo (var fields))
> user.foo
> user=> (user/map->foo {:a 67}) ;; funny
> #user.foo{:var nil, :fields nil, :a 67}
>
> Short of generating a string and calling eval on it, is this possible?
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