I need to correct that p2 and m1 should not have parens around
them.... sorry about that. Seemed obvious when I read it again this
morning.
The literal reader forms are even trickier in how they treat embedded
expressions. They seem to preserve (and not evaluate) the quoted
forms?
user=> (def p #user.Person[(str "a" "b") "c"])
#'user/p
user=> p
#user.Person{:first (str "a" "b"), :last "c"} ;; note the embedded
str here, not "ab"
user=> (:first p)
(str "a" "b") ;; aroo?
Surely, this is not the intended behavior?
On Oct 25, 8:53 pm, Alex Miller <[email protected]> wrote:
> So I'm catching up with the 1.3 defrecord additions (best docs here
> afaik:http://dev.clojure.org/display/design/defrecord+improvements-
> willhttp://clojure.org/datatypesbe updated?)
>
> In 1.2, records were constructed only with the positional Java
> constructor:
> (defrecord Person [first last])
> (Person. "alex" "miller")
>
> In 1.3, there are now a plethora of new construction options:
> Positional:
> p1) (Person. "alex" "miller") ;; "legacy" Java constructor
> form
> p2) (#user.Person["alex" "miller"]) ;; reader form, ns required
> p3) (->Person "alex" "miller") ;; factory function
>
> Map:
> m1) (#user.Person{:first "alex" :last "miller"}) ;; reader form, ns
> required, default print form
> m2) (map->Person {:first "alex" :last "miller"}) ;; factory function
> m3) (Person/create {:first "alex" :last "miller"}) ;; static class
> factory method
>
> So my question is what my first choice should be when constructing
> records and needing positional or map forms? Re positional forms, the
> p2 reader form requires the ns so is probably more typing than I'm
> likely to do. I'm guessing that p3 is now preferred over p1 as it
> hides the interop form. So I'll take p3 as the preferred first
> choice.
>
> For maps, m1 is the default form serialization form but requires the
> ns, so I doubt I would choose that first. m3 clearly seems designed
> for tool usage and does Java interop, so I'm guessing m2 is the likely
> preferred first choice.
>
> Thoughts?
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