[Haskell-beginners] Selecting Arguments in Function to Feed Map

[Tommy M. McGuire]

And to finish the example, fully parenthesized:

Prelude> let x = 4
Prelude> let y = [1,2,3,4]
Prelude> let z = 3
Prelude> map ((flip (f x)) z) y
[7,11,15,19]

I.e., apply f to x, flip the arguments, apply z, and map the result across y.

On 09/13/2010 09:01 AM, Alex Rozenshteyn wrote:
> To actually give the example:
> 
>> -- assuming that x and z are defined, and ys is the list
>> map (\y -> f x y z) ys
> 
> On Mon, Sep 13, 2010 at 9:16 AM, Magnus Therning <magnus at therning.org
> <mailto:magnus at therning.org>> wrote:
> 
>     On Mon, Sep 13, 2010 at 14:03, Lorenzo Isella
>     <lorenzo.isella at gmail.com <mailto:lorenzo.isella at gmail.com>> wrote:
>     > Dear All,
>     > Suppose you have the function
>     >
>     > f x y z = x*y +z
>     >
>     > and that you want to iterate it on a list
>     > z=[1,2,3,4], with
>     > x=4 and y=3
>     >
>     > then you would do the following
>     >
>     > map (f x y) z.
>     >
>     > Now consider the case in which the list is given by y e.g.
>     >
>     > y=[1,2,3,4], with
>     > x=4 and z=3.
>     >
>     > How can you iterate f on y (i.e. its second argument) while
>     keeping x and y
>     > fixed?
> 
>     Using a lambda expression (anonymous function) or through clever use
>     of flip.
> 
>     /M
> 
>     --
>     Magnus Therning                        (OpenPGP: 0xAB4DFBA4)
>     magnus＠therning．org          Jabber: magnus＠therning．org
>     http://therning.org/magnus         identi.ca
>     <http://identi.ca>|twitter: magthe
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> 
> 
> 
> -- 
>           Alex R
> 
> 
> 
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-- 
Tommy M. McGuire
mcguire at crsr.net