Re: Proposal: Add IsString instance for (Maybe a) to base

On 10 July 2013 07:24, Simon Hengel wrote:

Hi, what about adding

instance IsString a => IsString (Maybe a) where fromString = Just . fromString

It makes specifying optional String/Text/... values more convenient. Here is an example that uses System.Process.shell:

Use

shell "ls -l" { cwd = "/home/me" }

instead of

shell "ls -l" { cwd = Just "/home/me" }

I'm not yet sure how essential it is. But I somehow can't see any issues with it. So why not?

-0.5 from me; I think it's too easy to forget that it's a Maybe value there when refactoring, etc. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com