If you need it quoted in the "def" context:
(defmacro def-entity-and-attrs [entity-name key attrs-name attrs]
`(do (def ~attrs-name '~attrs)
(ds/defentity ~entity-name ~(vec (concat ['^:key key]
attrs)))))
Note the ' before attrs.
PS why is there a ' before ^:key? It doesn't seem to me like it does
anything.
On Mar 28, 1:13 pm, Thorsten Wilms <t...@freenet.de> wrote:
> Hi!
>
> Defining an entity with appengine-magic is straightforward:
> ----
> (ns tlog.models
> (:require [appengine-magic.services.datastore :as ds]))
>
> (ds/defentity Article [^:key slug, title, body, created-t, updated-t])
> ----
>
> But there are several places (other files), where that list sans the
> first element would be handy and I would like to avoid copy-pasting
> [title, body, created-t, updated-t].
>
> ds/defentity is a macro and won't work if it sees functions at compile
> time (I hope this way to put it is acceptable, but tell me if my mental
> model is lacking).
>
> amaloy helped me with an almost-solution. The following works:
> ----
> (defmacro def-entity-and-attrs [entity-name key attrs]
> `(ds/defentity ~entity-name ~(vec (concat ['^:key key] attrs))))
>
> (def-entity-and-attrs Article slug [title, body, created-t, updated-t])
> ----
>
> But it was meant to be:
> ----
> (defmacro def-entity-and-attrs [entity-name key attrs-name attrs]
> `(do (def ~attrs-name ~attrs)
> (ds/defentity ~entity-name ~(vec (concat ['^:key key] attrs)))))
>
> (def-entity-and-attrs Article slug
> attrs-name [title, body, created-t, updated-t])
> ----
> Fails with: "Unable to resolve symbol: title in this context"
> Or if I quote the vector: "clojure.lang.PersistentVector cannot be cast
> to clojure.lang.Symbol"
>
> I guess trying to access attrs-name from elsewhere would have been
> "fun", anyway.
>
> I would love to simply
> ----
> (def article-attrs '[title, body, created-t, updated-t])
> ----
> and work with that.
>
> It's not the first time I run into a situation where things beg to be
> composited/concatenated, but can't be, at least not easily.
>
> Any ideas?
>
> --
> Thorsten Wilms
>
> thorwil's design for free software:http://thorwil.wordpress.com/
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