[Haskell-beginners] Pattern Matching for record syntax

[Jeon-Young Kang]

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 <magnus at therning.org> wrote:

>
> 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 at therning.org   jabber: magnus at therning.org
> twitter: magthe               http://therning.org/magnus
>
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> belt?  Then why do you develop software as if shit doesn’t happen?
>      -- Alberto G ( http://makinggoodsoftware.com/2009/05/12/hdd/ )
>
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