[Haskell-beginners] Do I understand this well
rwobben at hotmail.com
Mon Jun 27 17:49:46 CEST 2011
> Date: Mon, 27 Jun 2011 16:14:28 +0100
> Subject: Re: [Haskell-beginners] Do I understand this well
> From: colinpauladams at gmail.com
> To: rwobben at hotmail.com
> You are onfusing defining a function with using it.
> addVectors (x1, y1) (x2, y2) = (x1 + x2, y1 + y2)
> defines the function addVectors
> (x, y) = addVectors (3.0, 4.5, -3.4, -5.6)
> calls the function, and binds x and y to the components of the result
> (pattern matching).
> fst . addVectors (3.0, 4.5, -3.4, -5.6)
> will return the x-compnent of the result (by composing functions)
I understand that I think
But when I ghci I enter :
(x, y) = addVectors (3.0, 4.5, -3.4, -5.6)
after I made a file with the file defenition.
I get this error :
:1:7 parse error on input =
So something is not right here.
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