Initial impl of depreciation function.

Dependencies

• [2] P6NR2CGX Beginning of implementation of depreciation.
• [3] N4NDAZYT Initial implementation of payouts.
• [4] Y35QCWYW Minor improvement in WorkIndex type to eliminate duplicated information.
• [*] NVOCQVAS Initial failing tests.
• [*] 7DBNV3GV Initial, stack-based impl of time log event reduction.

Change contents

• edit in src/Ananke/TimeLog.hs at line 20
  [7.119]

  [6.1028]
  + import Data.Ratio
• edit in src/Ananke/TimeLog.hs at line 107
  [3.970]

  [3.970]
  +

  + newtype Months = Months Integer

  +

  + monthsLength :: Months -> NominalDiffTime

  + monthsLength (Months i) = fromInteger $ 60 * 60 * 24 * 30 * i

  +

  + linearDepreciation :: Months -> Months -> Depreciation

  + linearDepreciation undepPeriod depPeriod =

  + let maxDepreciable :: NominalDiffTime

  + maxDepreciable = monthsLength undepPeriod + monthsLength depPeriod
• replacement in src/Ananke/TimeLog.hs at line 118
  [3.971]→[2.49:149](∅→∅)
  − linearDepreciation :: Depreciation

  − linearDepreciation =

  − let depf = undefined

  − Depreciation depf
  [3.971]
  + zeroTime :: NominalDiffTime

  + zeroTime = fromInteger 0

  +

  + depf :: NominalDiffTime -> Rational

  + depf dt = if dt < monthsLength undepPeriod

  + then 1

  + else toRational (max zeroTime (maxDepreciable - dt)) / toRational maxDepreciable

  + in Depreciation depf