What is the goal of this project? To pretty-print output? Or to be a
slightly friendlier version of Show?
To put it another way, what happens with more complicated structures?
As an example, what should the output be for this type [[String]] ?
[["abc", "def"], ["ghi"], ["jkl"]]
Or
[ ["abc", "def"]
, ["ghi"]
, ["jkl"]
]
On Mon, Nov 10, 2014 at 9:16 AM, Simon Hengel
So I would love to have tho following type class:
class Display a where display :: a -> String default display :: Show a => a -> String display = show
Note that for many Prelude types `show == display`, with the notable exception of String, where `display = id`. One use case where this matters is string interpolation [1][2][3].
I would also like a class like that to exist.
But I think it should be based on Text and Text builder rather than String (and hence be outside of base).
I created an initial draft:
https://github.com/sol/display/blob/master/src/Data/Display.hs
I named the builder version `displayBuilder` as I could not come up with any better name (suggestions much appreciated!).
In addition, I think the `display` method has to be outside of the class. Otherwise, if somebody defines `display` he end up with the default implementation of `displayBuilder` (which is based on show and may not be what is intended). Any input on that?
Pleas bikeshed hard!
Cheers, Simon _______________________________________________ Libraries mailing list Libraries@haskell.org http://www.haskell.org/mailman/listinfo/libraries