Allow custom decoder function

[laczoka]

Allow custom decoder function

[dakrone]

Hi @laczoka,

Unfortunately, I think this feature is outside the scope of cheshire, and would require architectural changes that would impact the performance-oriented nature. The json encoding/decoding library shouldn't handle coercing data.

[jzwolak]

I might agree with @dakrone , except that Chesire converts Clojure keywords to strings when creating JSON and then leaves them as strings when converting back to Clojure data structures. This is problematic as the encode and decode are not reverse operations of each other. Most users will assume they are. The problem, of course, is that JSON doesn't have an equivalent of Clojure's keyword type, so data is lost when converting to JSON. Providing the user with a way to handle this as part of the encode/decode fns would allow the user to make them the reverse operations for the user's data. Write the data to a web app backend... read it later... and something else comes out because of this.

So basically, Chesire makes a decision about type conversion that limits what data can be conveniently used and provides no mechanism for choosing otherwise. Yet, the key-fn is provided for the keys. I don't know... I think it's worth doing this.