The & is the same as $ with arguments inverted. So instead of t & myField . traversed . otherField %~ (++ "X") you could write myField . traversed . otherField %~ (++ "X") $ t (if I recall correctly...) Michal On Fri, Oct 10, 2014 at 11:03 AM, Nicola Gigante <nicola.gigante@gmail.com> wrote:
Il giorno 10/ott/2014, alle ore 16:36, Daniel Trstenjak < daniel.trstenjak@gmail.com> ha scritto:
Hi Nicola,
there's 'traversed' to access every entry of a traversable structure, e.g. appending a "X" at the end of each 'otherField':
t & myField . traversed . otherField %~ (++ "X")
And there's '^..' to return a list of each entry of a traversable
structure:
t ^.. myField . traversed . otherField
Thank you for both the answers!
So my error was to presume that everything can be done with (^.) (which is view, if I’m correct).
So I have to understand now, what is the & operator?
Greetings, Daniel
Thank you, Nicola _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe