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Comment by Zelphyr | Hacker News Reader

I just don't see how

  JWalk.getString(user, "them", "public_keys", "primary", "bundle");

is better than

  user.them.public_keys.primary.bundle

What am I missing?

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In Ruby or Python or JS, you should be able to do the user.them... form. In a statically typed language like Java or Go it’s harder, and I happened to be working on an Android app, thus Java.

Failure semantics are the obvious ones. At the very least you'll need some flavor of

    try {
      user.them.public_keys.primary.bundle
    } rescue {
      OhDamn
    }

Less obvious is the potential for multiple targets. JWalk probably doesn't do this, but it could. For more ideas for how this could work take a look at

http://research.microsoft.com/pubs/77415/theessenceofdataacc...

That JWalk library is in Java so there won't be something you can use dynamically like that.

AH! That's the missing piece for me. I thought this was all in JS.

You can use GSON and just parse your objects into POJOs and access them with dot notation.

In fact, now that I think about it, I wonder if you can rig up your POJOs as Java 8 Option<> and remove some of the null checking. I'll have to look into that.

That's a good place to start. Basing it on the list monad instead of the option monad gives you traversals with monoidal summaries.

What if them is `undefined`? You'll get an exception when usually you just want `undefined` as the answer.

As a side note, Ember.js has a nice method for this built in, that works on plain old Javascript objects as well as the heavier Ember ones:

Em.get(obj, 'user.them.public_keys.primary.bundle')

try{} ?

Not blowing up when one part of the chain goes "undefined"

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