[Haskell-cafe] What is the good way to work with list comprehension and UTCTime?

[Roman Cheplyaka]

Consider using the time-lens package.

  import Data.Time.Lens
  import Data.Lens.Common

List comprehension style:

  [modL seconds (+ fromIntegral n) t | n <- [0..]]
  [modL minutes (+ n) t | n <- [0..]]

(you need fromIntegral for seconds, because it is of fractional type in
Data.Time).

iterate style, as suggested by Karl:

  iterate (seconds ^+= 1) t
  iterate (minutes ^+= 1) t

On Fri, Sep 14, 2012 at 7:29 AM, Magicloud Magiclouds <
magicloud.magiclouds at gmail.com> wrote:

> Hi,
>   Simple usage, I could make an instance of Enum to UTCTime, so
> [utcTime..] could work. But that is so stiff. How if sometimes I want
> to step by 1 min, sometimes I want to step by 1 sec?
>   So I think some way like [ t | addUTCTime last 60 ] could be nice.
> But I cannot figure it out....
>   Any idea?
> --
> 竹密岂妨流水过
> 山高哪阻野云飞
>
> And for G+, please use magiclouds#gmail.com.
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