28 lines
728 B
Haskell
28 lines
728 B
Haskell
module Currency
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where
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import Utils
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import Types
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currencies =
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[
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Currency "$" 1
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,Currency "EUR" 0.760383
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,Currency "£" 0.512527
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,Currency "h" 60 -- hours
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,Currency "m" 1 -- minutes
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]
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getcurrency :: String -> Currency
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getcurrency s = head $ [(Currency symbol rate) | (Currency symbol rate) <- currencies, symbol==s]
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conversionRate :: Currency -> Currency -> Double
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conversionRate oldc newc = (rate newc) / (rate oldc)
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-- convenient amount constructors
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dollars n = Amount (getcurrency "$") n 2
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euro n = Amount (getcurrency "EUR") n 2
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pounds n = Amount (getcurrency "£") n 2
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hours n = Amount (getcurrency "h") n 2
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minutes n = Amount (getcurrency "m") n 2
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