[Haskell-cafe] Lenses: Changing/creating values deep inside JSON or HashMap

[David McBride]

Sorry, replying to list:

Would that not just be

json & key "outer" .~ object ["inner", "new-value"]

On Tue, Dec 20, 2016 at 8:26 AM, Jan von Löwenstein <
jan.loewenstein at gmail.com> wrote:

> I guess I haven't explained well what I am looking for.
>
> I want to set values deep inside a json structure, no matter if the full
> structure already exists.
>
> Go into "outer", if it doesn't exist make it an empty object.
> From there go into "inner" and set it to "new-value".
>
> The first part should be arbitrarily deep.
>
> Best
> Jan
>
> Benjamin Edwards <edwards.benj at gmail.com> schrieb am Di., 20. Dez. 2016
> um 13:42 Uhr:
>
>> If the desired function doesn't inspect the input then why not just use
>> const <<thing you want>> ?
>>
>> As to the lenses part: If you use a prism and it doesn't match, then it's
>> a noop.
>>
>> On Tue, 20 Dec 2016 at 09:38 Jan von Löwenstein <
>> jan.loewenstein at gmail.com> wrote:
>>
>> Hi,
>>
>> I want to have code that produces the following result no matter if input
>> A or B was given:
>>
>> Result:
>> {
>>   "outer" : {
>>                   "inner" : "new-value"
>>                 }
>> }
>>
>> A:
>> {
>>   "outer" : {
>>                   "inner" : "old-value"
>>                 }
>> }
>>
>> B:
>> {}
>>
>> `json & key "outer"._Object.key "inner" .~ "new-value"` didn't work.
>>
>> Is what I want even possible with lenses?
>>
>> Best
>> Jan
>>
>> _______________________________________________
>> Haskell-Cafe mailing list
>> To (un)subscribe, modify options or view archives go to:
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
>> Only members subscribed via the mailman list are allowed to post.
>>
>>
> _______________________________________________
> Haskell-Cafe mailing list
> To (un)subscribe, modify options or view archives go to:
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> Only members subscribed via the mailman list are allowed to post.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20161220/a3ede0b9/attachment.html>