toUrlPiece for NominalDiffTime loses precision

[fizruk]

toUrlPiece for NominalDiffTime loses precision

[rockbmb]

PR #87 fixes #77, so if it gets merged this issue can be completed.

[rockbmb]

This issue can be easily fixed with this function recently introduced to time, but it cannot be implemented yet.

It relies on time-1.9.1, and trying to use it gives the following problem:

In the dependencies for Cabal-2.2.0.1:
    time-1.9.1 from stack configuration does not match >=1.4 && <1.9  (latest
               matching version is 1.8.0.4)
needed due to http-api-data-0.3.10 -> Cabal-2.2.0.1

In the dependencies for directory-1.3.1.5:
    time-1.9.1 from stack configuration does not match >=1.4 && <1.9  (latest
               matching version is 1.8.0.4)
needed due to http-api-data-0.3.10 -> directory-1.3.1.5

In the dependencies for unix-2.7.2.2:
    time-1.9.1 from stack configuration does not match >=1.2 && <1.9  (latest
               matching version is 1.8.0.4)
needed due to http-api-data-0.3.10 -> unix-2.7.2.2

The newest version of directory, 1.3.3.1, already uses time (>=1.4 && <1.10), and the unreleased 2.8.0.0 version of unix as well. However, the latest published version of Cabal, which is 2.4.0.1, still uses time (>=1.4.0.1 && <1.9), and the latest published version of unix, 2.7.2.2, uses time (>=1.2 && <1.9).

As such, a way should be found to fix this problem without relying on a newer version of time, at least for the time being.

[fizruk]

Indeed. For earlier versions I guess we can use realToFrac :: NominalDiffTime -> Pico.

@rockbmb are you willing to submit a PR? 😊

I think you can use CPP to produce something like this:

#if MIN_VERSION_time(1,9,1)
nominalDiffTimeToSeconds
#else
(realToFrac :: NominalDiffTime -> Pico)
#endif

@phadej is it okay to use CPP here?

[phadej]

I'd write something like

import Data.Time (NominalDiffTime)

#if MIN_VERSION_time(1,9,1)
import Data.Time (nominalDiffTimeToSeconds)
#endif

-- possibly more imports

#if !MIN_VERSION_time(1,9,1)
nominalDiffTimeToSeconds :: NominalDiffTime -> Pico
nominalDiffTimeToSeconds = realToFrac
#endif

[rockbmb]

@fizruk will submit a PR 👍

[phadej]

Fixed in #88 #89