Thanks Magnus Therning.
Actually, this is NOT homework. I am just studying Haskell for my current
research.
I've tried "filter" before. But I couldn't reach what I want to do.
it seems that filter is only applicable to list, not "record syntax".
Do I need functor for this??
Best,
On Thu, Jan 7, 2016 at 5:24 PM, Magnus Therning
Jeon-Young Kang writes:
Dear All.
Hope your 2016 is off to a great start.
I would like to get results from pattern matching or something.
Here is the my code.
data Person = Person {name :: String, age :: Int}
names = ["tom", "sara"] -- list of names, String
persons = [Person {name = "tom", age = 10}, Person {name="sara", age=9}, Person {name = "susan", age = 8}].
Is there any solution to get the age of "tom" and "sara"?
I have no idea of pattern matching for this one.
I've tried to use recursion, but I couldn't find any solution for list of records.
How about using `filter`[1] over `persons` with a function checking if the name is in `names`?
I'm sorry, but this sounds like home work so you won't get more than this from me.
/M
[1]: http://hackage.haskell.org/package/base-4.8.1.0/docs/Data-List.html#v:filter
-- Magnus Therning OpenPGP: 0x927912051716CE39 email: magnus@therning.org jabber: magnus@therning.org twitter: magthe http://therning.org/magnus
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