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2020-04-29

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#clojure-uk
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2020-04-29
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dharrigan05:04:44

Good Morning!

thomas07:04:18

mogge 😼

guy08:04:23

Morning!

dharrigan10:04:59

I'm having a bit of an hard time trying to massage some data into another structure, can anyone help? I'm open to using clojure or specter or whatever to get the job done 🙂 Here's the original structure...

dharrigan10:04:08

{"Foobar Motor Group" [{:poi_name "Foobar Motor Group",
                        :poi_type "GARAGE",
                        :trip_location #object[org.postgresql.util.PGobject
                                               "0xbda6575"
                                               "44A40"],
                        :trip_timestamp #inst "2020-02-03T10:41:50"}
                       {:poi_name "Foobar Motor Group",
                        :poi_type "GARAGE",
                        :trip_location #object[org.postgresql.util.PGobject
                                               "0x258b4c14"
                                               "44A40"],
                        :trip_timestamp #inst "2020-02-03T10:08:19"}
                       {:poi_name "Foobar Motor Group",
                        :poi_type "GARAGE",
                        :trip_location #object[org.postgresql.util.PGobject
                                               "0xed60b3b"
                                               "44A40"],
                        :trip_timestamp #inst "2020-02-03T09:40:19"}]}

dharrigan10:04:15

and this is what I want to end up with:

dharrigan10:04:24

{"Foobar Motor Group" [{:poi_name "Foobar Motor Group",
                        :poi_type "GARAGE",
                        :trips [{:trip_location #object......,
                                 :trip_timestamp #inst......}
                                {:trip_location #object......,
                                 :trip_timestamp #inst......}]}]}

alexlynham11:04:15

in this example, all the things in the vector are garages, right? if they're unique, any reason why it isn't a hash rather than a vec?

dharrigan12:04:12

It's just an example, there are multitude of other types in the result set returned

dharrigan12:04:24

i.e., poi_type "ROUNDABOUT" etc...

guy12:04:24

But the :poi_name is the same right?

guy12:04:34

it looks like uve done a group-by on :poi_name

guy12:04:17

So then u want to merge together all the maps with the same name type and then add in the trips basically in a vec?

dharrigan12:04:17

yes, in effect deduping the poi's into one and then adding the trips associated with the poi into a vec

dharrigan12:04:33

I was playing with group-by to give me a start to see what I can achieve.

dharrigan12:04:49

Then i went down a rabbit hole of map, reduce-kv, etc..

Ben Hammond12:04:04

group-by would be the obvious choice

Ben Hammond12:04:27

with a couple of transforms either side

Ben Hammond12:04:47

• transform to flattten data structure • group-by • transform group-by output to what you want

👍 1
Ben Hammond12:04:09

but that keep the individual steps distinct and obvious

Ben Hammond12:04:29

don't try to do too much in one function - makes it difficult to maintain

Ben Hammond12:04:05

but keep it really explicit what is the 'group-by' key

Ben Hammond12:04:10

and what is the 'group-by' data

dharrigan12:04:48

I did (group-by :poi_name results) where results is similar to the example I gave at the start 🙂

dharrigan12:04:57

Just to get things rolling in my head, mind 🙂

Ben Hammond12:04:08

so then you have a simple (medley/map-vals transform to do to get thing in the shape thatt you want

dharrigan12:04:28

Reading up on map-vals

Ben Hammond12:04:48

nah its just a 

(mapv #(select-keys % [:trip_location :trip_timestamp) ...)
innitt

dharrigan12:04:30

trying that out 🙂

guy12:04:41

Yeah i thought that at first too @U793EL04V haha

dharrigan13:04:58

it produces the shape I'm interested in

dharrigan13:04:10

it's probably immature and efficient, so would welcome improvements 🙂

Ben Hammond14:04:01

usually the most important question is > how easy is it to maintain

Ben Hammond14:04:56

How quickly would the 6-months-in-the-future you understand it

dharrigan14:04:39

Probably well enough, and hopefully more experienced enough to say "that could be rewritten better!" 🙂

alexlynham14:04:56

I think that snippet looks okay, I'd just format it so it's easier to visually parse and maybe rename a couple of the fns to be really explicit, but then my fn names are usually on the long side

dharrigan14:04:02

Thank you! 🙂

dharrigan10:04:47

It's basically collapsing all the trips into one collection, under one "poi"

guy10:04:59

sorta smells like group by i dnno

guy10:04:04

let me take it to the repl

guy10:04:54

nvm its not that haha I've got a meeting now, ill post what ive got later after it

jasonbell10:04:28

Morning friends

👋 2
rhinocratic11:04:59

Cabin fever is definitely starting to get the better of me. I started a blog... https://blog.nerdwick.net/

👀 1
folcon13:04:41

Well that was just lovely =)…

rhinocratic14:04:48

Why thank you! 🙂

1
Eamonn Sullivan19:04:13

That's a really nice looking site! I did the same thing (https://eamonnsullivan.co.uk/), out of pure boredom. Mine looks like something out of the early noughts...

👍 2
rhinocratic19:04:03

Thanks! Yours looks great - nice and clean, and with far more content than mine! Early days though... Subscribed!

folcon20:04:29

snap @UR71VR71S, I too used the basic cryogen template ;)… http://folcon.github.io/

Conor12:04:47

Flann O'Brien, I approve

rhinocratic12:04:01

Thank you! My all-time favourite author.