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Add a convenient way to get the Milliseconds between two Instants #98
Description
This is a use case I have often when timing things.
I would like to avoid running unInstant in application code.
Maybe like this:
-- | Get the amount of milliseconds between the first and second Instant
-- | for example:
-- | ```
-- | do
-- | start <- Instant.now
-- | aLongRunningEffect
-- | end <- Instant.now
-- | let duration = Instant.delta end start
-- | log ("A long running effect took " <> show duration)
-- | ```
delta ∷ Instant → Instant → Milliseconds
delta i1 i2 = (unInstant i1) <> negateDuration (unInstant i2)
Activity
garyb commentedon May 19, 2022
Yeah agreed, I was doing something with this just the other day and was surprised we'd not included something for it already.
I'd be tempted to make the type something like
duration :: { start :: Instant, end :: Instant } -> Millisecondsto avoid confusion over argument order.hdgarrood commentedon May 19, 2022
This feels to me like it could be a nice use case for the Duration class?
i-am-the-slime commentedon May 19, 2022
Yes, but it risks to also be a bit annoying when trying to just log it with
showfor example, right?hdgarrood commentedon May 19, 2022
Yeah. Either way it's easy to get what you want. I guess the other
Instantfunctions work inMillisecondsso maybe it'd make more sense to do the same here.