[erlang-questions] Access JSON in Erlang like you do in JavaScript

Ryan Zezeski <>
Wed Oct 20 04:12:17 CEST 2010


On Tue, Oct 19, 2010 at 8:24 PM, Jesper Louis Andersen <
> wrote:

>
> Have you considered wrapping the code into a parse transform so you
> can "embed" the javascript notation into Erlang directly?
>
>
I have, and my first attempt was to use a parse transform.  However, a parse
transform requires that it's valid Erlang syntax and I don't believe
something like "Obj.post.title" is considered valid Erlang syntax--correct?
 You could do something like "Obj/post/title" but at that point it looks
more similar to XPath.  Maybe I'll play around with this more.

Another option is to write an xpath-like query tool, perhaps with a
> Zipper construction on the parse tree so you have a neat continuation
> for the next match, should you need it. This is probably my solution,
> if I need to process JSON documents in the future. You already made
> the first venture into this - think jQuery DOM selectors on steroids
> for selection into JSON structures.
>

Huet's Zipper was definitely in my mind but I didn't do anything with it.  I
think I like the sound of jQuery for JSON but I'm not sure what that would
look like.  Has anyone done this in the JavaScript world?

Let's say I had an object like so:

var Obj = { posts: [{title: "Foo", body: "..."}, {title: "Bar", body:
"..."}, ...]};

Are you talking about having something like the following...

$(Obj, "title").each( function() { alert($(this).value); };

Pardon if my syntax is off, it's been a while since I've done
JavaScript/jQuery development.


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