Ah, actually, there's one mistake in my responses, you want to change out
the element based on id, not index, in which case I'd simply recommend map
or mapv. Just remember anytime you change one thing you have to iterate
over the whole vector, worst-case, O(n).
If you use a map of :id to record, updates are O(log32 n), which is much
better.
On Tue, Apr 8, 2014 at 7:18 PM, Gary Trakhman <gary.trakh...@gmail.com>wrote:
> Alternatively, you could sprinkle (into [] ..) to feed the result of
> remove/filter back into a vector.
>
>
> On Tue, Apr 8, 2014 at 7:16 PM, Gary Trakhman <gary.trakh...@gmail.com>wrote:
>
>> My response had the assumption that this is an example of an X-Y problem
>> :-).
>>
>> If you want to literally do what you said, then you can't use update-in
>> because the value at that point is a seq.
>>
>> If you have to continue in this way, for some reason, what you probably
>> want is map-indexed, which provides the index of the element as one of the
>> parameters to the mapping function.
>>
>> You could use a helper to build a function that only operates on that
>> particular element.
>>
>> I caution that you might run into a stackoverflow due to laziness if you
>> do this enough without realizing the seq.
>>
>> This just feels unidiomatic to me, though.
>>
>>
>>
>>
>>
>> On Tue, Apr 8, 2014 at 7:10 PM, Ivan Schuetz <ivanschu...@gmail.com>wrote:
>>
>>> As I said I already looked in the docs, and know these basic examples,
>>> but I don't know how to do:
>>>
>>> *"How can I say in a vector of records e.g. "set name of element to
>>> "foo" where id is equal 1"?"*
>>>
>>>
>>> The remove by Id works, I posted it only to show something which might
>>> be similar to the update I'm looking for.
>>>
>>> I also wrote filter:
>>>
>>> (nth (filtered (filter #(= (:id %) id) @dataprovider/products)) 0)
>>>
>>> This gives me the element I need to update, but I still don't know how I
>>> update this element in the vector.
>>>
>>>
>>>
>>> Am Mittwoch, 9. April 2014 00:27:41 UTC+2 schrieb Gary Trakhman:
>>>>
>>>> Maybe this will help:
>>>>
>>>> > (update-in [[] 2 3 4] [0] (constantly 1))
>>>> [1 2 3 4]
>>>>
>>>> > (update-in [[] 2 3 4] [2] (constantly 1))
>>>> [ [ ] 2 1 4]
>>>>
>>>> > (update-in [[] 2 3 4] [1] (constantly 1))
>>>> [ [ ] 1 3 4]
>>>>
>>>> > (update-in [[] 2 3 4] [0 :a] (constantly :b))
>>>> java.lang.IllegalArgumentException: Key must be integer
>>>>
>>>> > (update-in [[] 2 3 4] [0 0 :a] (constantly :b))
>>>> [ [{:a :b}] 2 3 4]
>>>>
>>>>
>>>> On Tue, Apr 8, 2014 at 6:22 PM, Ivan Schuetz <ivans...@gmail.com>wrote:
>>>>
>>>>> I would use merge to update the record with the map... but I don't
>>>>> know how to get it from filter operation. Maybe I should not solve this
>>>>> with 1-liner.
>>>>>
>>>>> Am Mittwoch, 9. April 2014 00:14:09 UTC+2 schrieb Ivan Schuetz:
>>>>>
>>>>>> Ahh dataprovider/products should be "items". Forgot to "simplify".
>>>>>>
>>>>>>
>>>>>> Am Mittwoch, 9. April 2014 00:12:48 UTC+2 schrieb Ivan Schuetz:
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> sorry I don't get it. I just started learning Clojure.
>>>>>>>
>>>>>>> I did this to remove element with id 1
>>>>>>>
>>>>>>> (commute items #(remove (fn [x](= (:id x) id)) %))
>>>>>>>
>>>>>>> From your statement I understand update-in would work for the
>>>>>>> update, but I don't know the syntax. Something like
>>>>>>>
>>>>>>> (commute dataprovider/products #(update-in % {:id id} (->Item
>>>>>>> ???) ))
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Am Mittwoch, 9. April 2014 00:01:00 UTC+2 schrieb Gary Trakhman:
>>>>>>>>
>>>>>>>>
>>>>>>>>> But 1. Can't find examples with records, 2. Not sure if I can use
>>>>>>>>> it to update a different field than the one I'm using to do the
>>>>>>>>> query. In
>>>>>>>>> the examples fields seem to be the same.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> Leave off the last path segment and return the full updated record,
>>>>>>>> not just the new field's value.
>>>>>>>>
>>>>>>> --
>>>>> You received this message because you are subscribed to the Google
>>>>> Groups "Clojure" group.
>>>>> To post to this group, send email to clo...@googlegroups.com
>>>>>
>>>>> Note that posts from new members are moderated - please be patient
>>>>> with your first post.
>>>>> To unsubscribe from this group, send email to
>>>>> clojure+u...@googlegroups.com
>>>>>
>>>>> For more options, visit this group at
>>>>> http://groups.google.com/group/clojure?hl=en
>>>>> ---
>>>>> You received this message because you are subscribed to the Google
>>>>> Groups "Clojure" group.
>>>>> To unsubscribe from this group and stop receiving emails from it, send
>>>>> an email to clojure+u...@googlegroups.com.
>>>>>
>>>>> For more options, visit https://groups.google.com/d/optout.
>>>>>
>>>>
>>>> --
>>> You received this message because you are subscribed to the Google
>>> Groups "Clojure" group.
>>> To post to this group, send email to clojure@googlegroups.com
>>> Note that posts from new members are moderated - please be patient with
>>> your first post.
>>> To unsubscribe from this group, send email to
>>> clojure+unsubscr...@googlegroups.com
>>> For more options, visit this group at
>>> http://groups.google.com/group/clojure?hl=en
>>> ---
>>> You received this message because you are subscribed to the Google
>>> Groups "Clojure" group.
>>> To unsubscribe from this group and stop receiving emails from it, send
>>> an email to clojure+unsubscr...@googlegroups.com.
>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>
>>
>
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
