Thanks, all. Earlier, I was going to ask how to break out of a sequence op prematurely, i.e., you give it some replication number but want to break early if you get an end-flag value. While I was composing the post I thought of using Maybe for the good values and Nothing for the end value. Ergo, losing the Nothings at the end. I was passing a map and an empty list into some state, but since the map doesn't change once it's created I moved it into a Reader. I was using the list to collect the elements but thought I can get that functionality automatically using sequence. So, one thing leads to another. It's interesting how ideas begin bubbling up after one absorbs some critical mass of Haskell. Michael --- On Mon, 5/23/11, Malcolm Wallace <malcolm.wall...@me.com> wrote:
From: Malcolm Wallace <malcolm.wall...@me.com> Subject: Re: [Haskell-cafe] [Maybe Int] sans Nothings To: "haskell-cafe Cafe" <haskell-cafe@haskell.org> Date: Monday, May 23, 2011, 12:35 PM On 23 May 2011, at 17:20, michael rice wrote: > What's the best way to end up with a list composed of only the Just values, > no Nothings? Alternatively, [ x | Just x <- originals ] It also occurs to me that perhaps you still want the Just constructors. [ Just x | Just x <- originals ] [ x | x@(Just _) <- originals ] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
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