To stay on the same topice (almost :stuck_out_tong...
# getting-startedc
CamilleBC
10/03/2018, 8:59 AMTo stay on the same topice (almost š ), I have a question about data types. For each item, I have a KEY, a PATH and a NAME value.
I would like to be able to find the two others quickly if I have any of the three. Is there a kotlin way to do it efficiently? I was thinking of doing a hashmap with a data class that contains the two other value, but then it only works if I searrch by KEY, not by PATH or NAME. Any idea?
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Hamza
10/03/2018, 9:00 AMyou could create a ātripleā hype
Hamza
10/03/2018, 9:01 AMthat has the vals first, second, and third
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CamilleBC
10/03/2018, 9:02 AMBut can I search in a triple? Like if I know the second value, can I then easily get first and third?
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arekolek
10/03/2018, 9:02 AMhow big is the collection? if itās a few thousand items, you could probably do a linear search and it would still be quick
also, how often do you expect to add/remove items from that collection and how often do you expect to query it?
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Hamza
10/03/2018, 9:03 AMcreate a custom type that extends iterable
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CamilleBC
10/03/2018, 9:04 AMIt's a very tiny collection, and I do not plan to modify it at all. I was trying to mimic some kind of static searchable collection.
CamilleBC
10/03/2018, 9:05 AMThanks Hamza, I will try to create my custom type, it will be a good learning experience
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Konstantin Petrukhnov
10/03/2018, 9:06 AMcreate type, that have 3 maps inside?
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arekolek
10/03/2018, 9:06 AMif itās tiny, the overhead of the hashmap could be greater than the benefit from better time complexity of the lookup
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Konstantin Petrukhnov
10/03/2018, 9:06 AMas long as each K/P/N are unique.
Konstantin Petrukhnov
10/03/2018, 9:07 AMIf you have 2 items with same name, but different path... what should it return?
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CamilleBC
10/03/2018, 9:07 AMThey are. I am probably just going to create a custom iterable with a triple.
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Hamza
10/03/2018, 9:09 AMwhat you could possibly do is just have a type that holds three values, and hhave a list of them
Hamza
10/03/2018, 9:09 AMthen use map and filter
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CamilleBC
10/03/2018, 9:09 AM@Konstantin Petrukhnov They are unique š
CamilleBC
10/03/2018, 9:09 AM@Hamza Good idea. I am discovering Kotlin, so thanks for all the advices š
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Hamza
10/03/2018, 9:10 AMnp
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CamilleBC
10/03/2018, 9:14 AM@arekolek Thanks for the reminder of the HashMap overhead! I'll keep that in mind when dealing with small datasets.
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arekolek
10/03/2018, 9:16 AMSure š on the other hand I donāt care about that overhead if itās convenient to use a map instead of using
list.find { }k
Konstantin Petrukhnov
10/03/2018, 9:17 AM@arekolek what is tiny? At what size it get significantly better/worse?
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CamilleBC
10/03/2018, 9:17 AMYes I tend to be guilty of that š
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arekolek
10/03/2018, 9:17 AM@Konstantin Petrukhnov thatās something one would have to measure
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Konstantin Petrukhnov
10/03/2018, 9:18 AMare we talking about 10s or 1000s?
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Hamza
10/03/2018, 9:21 AMim thinkimg 100-500
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arekolek
10/03/2018, 9:24 AMhereās an example in .NET, with add/remove
https://i.stack.imgur.com/O4ly9.pngā¾
arekolek
10/03/2018, 9:25 AMBut Iād treat it more as a tidbit, than something that should guide development š