1 {-# LANGUAGE DeriveDataTypeable #-}
2 {-# LANGUAGE FlexibleContexts #-}
3 {-# LANGUAGE FlexibleInstances #-}
4 {-# LANGUAGE OverloadedStrings #-}
5 {-# LANGUAGE TypeFamilies #-}
6 {-# LANGUAGE TypeSynonymInstances #-}
7 {-# OPTIONS_GHC -fno-warn-orphans #-}
8 module Hcompta.Amount where
10 import Control.DeepSeq
12 import qualified Data.List
13 import qualified Data.Map.Strict as Data.Map
14 import Data.Map.Strict (Map)
15 import qualified Data.Foldable
16 import Data.Typeable ()
18 import qualified Hcompta.Balance as Balance
19 import qualified Hcompta.GL as GL
20 import qualified Hcompta.Amount.Quantity as Quantity
21 import qualified Hcompta.Amount.Style as Style
22 import qualified Hcompta.Amount.Unit as Unit
24 -- * Type synonyms to submodules
26 type Quantity = Quantity.Quantity
27 type Style = Style.Style
30 -- * The 'Amount' type
34 { quantity :: !Quantity
37 } deriving (Data, Show, Typeable)
38 instance NFData (Amount) where
39 rnf (Amount q s u) = rnf q `seq` rnf s `seq` rnf u
41 instance Eq Amount where
43 Amount{quantity=q0, unit=u0}
44 Amount{quantity=q1, unit=u1} =
48 EQ -> (==) q0 q1 -- NOTE: MUST already be rounded to Style.precision
50 instance Ord Amount where
52 Amount{quantity=q0, unit=u0}
53 Amount{quantity=q1, unit=u1} =
57 EQ -> compare q0 q1 -- NOTE: MUST already be rounded to Style.precision
59 instance Balance.Amount Amount where
60 type Amount_Unit Amount = Unit
61 amount_null = (==) Quantity.zero . quantity
63 amount_negate = negate
65 instance Balance.Amount (Map Unit Amount) where
66 type Amount_Unit (Map Unit Amount) = Unit
67 amount_null = Data.Foldable.all ((==) Quantity.zero . quantity)
68 amount_add = Data.Map.unionWith (+)
69 amount_negate = Data.Map.map negate
71 instance GL.Amount Amount where
72 type Amount_Unit Amount = Unit
75 instance GL.Amount (Map Unit Amount) where
76 type Amount_Unit (Map Unit Amount) = Unit
77 amount_add = Data.Map.unionWith (+)
79 -- | An 'Amount' is a partially valid 'Num' instance:
81 -- * (+) operator requires both operand to have the same 'Unit' (homogeneity constraint).
82 -- * (*) operator requires at least one operand with an empty 'Unit' ('scalar').
83 instance Num Amount where
84 abs a@Amount{quantity=q} = a{quantity=abs q}
85 fromInteger = scalar . fromInteger
86 negate a@Amount{quantity=q} = a{quantity=negate q}
87 signum a@Amount{quantity=q} = a{quantity=signum q}
89 let s@(Style.Style{Style.precision=p}) = Style.union (style a) (style b) in
90 a{ quantity = Quantity.round p $ quantity a + quantity b
95 else error "(+) on non-homogeneous units"
98 let Style.Style{Style.precision=p} = s in
99 a{ quantity = Quantity.round p $ quantity a * quantity b
106 then (Style.union (style a) (style b), "")
107 else (style b, unit b)
108 | unit b == "" = (style a, unit a)
109 | otherwise = error "(*) by non-scalar unit"
116 { quantity = Quantity.zero
121 -- *** From 'Quantity'
123 -- | Return an 'Amount' with 'unit' = Unit.'Unit.nil'.
124 scalar :: Quantity -> Amount
128 , style = Style.Style
129 { Style.fractioning = Just '.'
130 , Style.grouping_fractional = Just $ Style.Grouping ',' [3]
131 , Style.grouping_integral = Just $ Style.Grouping ',' [3]
132 , Style.precision = maxBound
133 , Style.unit_side = Just Style.Side_Right
134 , Style.unit_spaced = Just False
139 -- | <https://en.wikipedia.org/wiki/Swiss_franc Swiss franc> unit of currency.
140 chf :: Quantity -> Amount
144 , style = Style.Style
145 { Style.fractioning = Just ','
146 , Style.grouping_fractional = Just $ Style.Grouping '.' [3]
147 , Style.grouping_integral = Just $ Style.Grouping '.' [3]
148 , Style.precision = 2
149 , Style.unit_side = Just Style.Side_Right
150 , Style.unit_spaced = Just False
154 -- | <https://en.wikipedia.org/wiki/Yuan Yuan> unit of currency.
155 cny :: Quantity -> Amount
159 , style = Style.Style
160 { Style.fractioning = Just ','
161 , Style.grouping_fractional = Just $ Style.Grouping '.' [3]
162 , Style.grouping_integral = Just $ Style.Grouping '.' [3]
163 , Style.precision = 2
164 , Style.unit_side = Just Style.Side_Right
165 , Style.unit_spaced = Just False
169 -- | <https://en.wikipedia.org/wiki/Euro Euro> unit of currency.
170 eur :: Quantity -> Amount
174 , style = Style.Style
175 { Style.fractioning = Just ','
176 , Style.grouping_fractional = Just $ Style.Grouping '.' [3]
177 , Style.grouping_integral = Just $ Style.Grouping '.' [3]
178 , Style.precision = 2
179 , Style.unit_side = Just Style.Side_Right
180 , Style.unit_spaced = Just False
184 -- | <https://en.wikipedia.org/wiki/Pound_sterling Pound sterling> unit of currency.
185 gbp :: Quantity -> Amount
189 , style = Style.Style
190 { Style.fractioning = Just '.'
191 , Style.grouping_fractional = Just $ Style.Grouping ',' [3]
192 , Style.grouping_integral = Just $ Style.Grouping ',' [3]
193 , Style.precision = 2
194 , Style.unit_side = Just Style.Side_Left
195 , Style.unit_spaced = Just False
199 -- | <https://en.wikipedia.org/wiki/Indian_rupee Indian rupee> unit of currency.
200 inr :: Quantity -> Amount
204 , style = Style.Style
205 { Style.fractioning = Just ','
206 , Style.grouping_fractional = Just $ Style.Grouping '.' [3]
207 , Style.grouping_integral = Just $ Style.Grouping '.' [3]
208 , Style.precision = 2
209 , Style.unit_side = Just Style.Side_Right
210 , Style.unit_spaced = Just False
214 -- | <https://en.wikipedia.org/wiki/Japanese_yen Japanese yen> unit of currency.
215 jpy :: Quantity -> Amount
219 , style = Style.Style
220 { Style.fractioning = Just '.'
221 , Style.grouping_fractional = Just $ Style.Grouping ',' [3]
222 , Style.grouping_integral = Just $ Style.Grouping ',' [3]
223 , Style.precision = 2
224 , Style.unit_side = Just Style.Side_Left
225 , Style.unit_spaced = Just False
229 -- | <https://en.wikipedia.org/wiki/Russian_ruble Russian ruble> unit of currency.
231 -- NOTE: Ꝑ (U+A750) is used as a replacement latin letter,
232 -- because GHC currently chokes on ₽ (U+20BD),
233 -- which is the recently (2014/02) assigned Unicode code-point
234 -- for this currency.
235 rub :: Quantity -> Amount
239 , style = Style.Style
240 { Style.fractioning = Just '.'
241 , Style.grouping_fractional = Just $ Style.Grouping ',' [3]
242 , Style.grouping_integral = Just $ Style.Grouping ',' [3]
243 , Style.precision = 2
244 , Style.unit_side = Just Style.Side_Left
245 , Style.unit_spaced = Just False
249 -- | <https://en.wikipedia.org/wiki/United_States_dollar United States dollar> unit of currency.
250 usd :: Quantity -> Amount
254 , style = Style.Style
255 { Style.fractioning = Just '.'
256 , Style.grouping_fractional = Just $ Style.Grouping ',' [3]
257 , Style.grouping_integral = Just $ Style.Grouping ',' [3]
258 , Style.precision = 2
259 , Style.unit_side = Just Style.Side_Left
260 , Style.unit_spaced = Just False
267 -- | Return 'True' if and only if 'Amount'’s 'Quantity' is zero.
269 -- NOTE: the 'Amount'’s 'quantity' MUST be have been rounded at 'Amount'’s 'style'’s 'Style.precision'.
270 is_zero :: Amount -> Bool
271 is_zero = Quantity.is_zero . quantity
273 -- * The 'Amount_by_Unit' mapping
276 = Data.Map.Map Unit Amount
277 type By_Unit = Amount_by_Unit
279 -- | 'Amount_by_Unit'’s is a partially valid 'Num' instance.
281 -- * (*) operator is not defined.
282 instance Num Amount_by_Unit where
283 abs = Data.Map.map (\a@Amount{quantity=q} -> a{quantity=abs q})
284 fromInteger = Data.Map.singleton "" . fromInteger
285 negate = Data.Map.map (\a@Amount{quantity=q} -> a{quantity=negate q})
286 signum = Data.Map.map (\a@Amount{quantity=q} -> a{quantity=signum q})
287 (+) = Data.Map.unionWith (+)
288 (*) = error "(*) not-supported"
290 type Signs = (Int, Int)
292 signs :: Amount_by_Unit -> Signs
293 signs = Data.Map.foldl
294 (\(nega, plus) amt ->
295 case flip compare 0 $ quantity amt of
296 LT -> (nega - 1, plus)
298 GT -> (nega, plus + 1))
303 nil_By_Unit :: Amount_by_Unit
309 -- | Return 'True' if and only if all 'Amount's satisfy 'is_zero'.
310 are_zero :: Amount_by_Unit -> Bool
311 are_zero = Data.Foldable.all is_zero
313 -- | Return a tuple associating the given 'Amount' with its 'Unit'.
314 assoc_by_unit :: Amount -> (Unit, Amount)
315 assoc_by_unit amount = (unit amount, amount)
317 -- | Return a 'Data.Map.Map' associating the given 'Amount's with their respective 'Unit'.
318 from_List :: [Amount] -> Amount_by_Unit
320 Data.Map.fromListWith (flip (+)) $ -- NOTE: flip to propagate 'Style' first to last.
321 Data.List.map assoc_by_unit amounts
325 -- ** Class 'Sumable'
327 ( Data (Sumable_Unit a)
330 , Ord (Sumable_Unit a)
331 , Show (Sumable_Unit a)
333 , Typeable (Sumable_Unit a)
337 -- sumable_add :: a -> a -> a
338 sumable_positive :: a -> Maybe a
339 sumable_negative :: a -> Maybe a
341 instance Sumable Amount where
342 type Sumable_Unit Amount = Unit
345 case compare (quantity a) Quantity.zero of
350 case compare (quantity a) Quantity.zero of
355 instance Sumable (Map Unit Amount) where
356 type Sumable_Unit (Map Unit Amount) = Unit
359 let r = Data.Map.mapMaybe sumable_positive a in
364 let r = Data.Map.mapMaybe sumable_negative a in
369 instance Sumable amount => Sumable (Sum amount) where
370 type Sumable_Unit (Sum amount) = Sumable_Unit amount
371 sumable_negative amt =
373 Sum_Negative _ -> Just $ amt
374 Sum_Positive _ -> Nothing
375 Sum_Both n _ -> Just $ Sum_Negative n
376 sumable_positive amt =
378 Sum_Negative _ -> Nothing
379 Sum_Positive _ -> Just $ amt
380 Sum_Both _ p -> Just $ Sum_Positive p
382 -- | Sum separately keeping track of negative and positive 'amount's.
384 = Sum_Negative !amount
385 | Sum_Positive !amount
386 | Sum_Both !amount !amount
387 deriving (Data, Eq, Show, Typeable)
388 instance NFData amount => NFData (Sum amount) where
389 rnf (Sum_Negative a) = rnf a
390 rnf (Sum_Positive a) = rnf a
391 rnf (Sum_Both a0 a1) = rnf a0 `seq` rnf a1
393 instance Functor Sum where
394 fmap f (Sum_Negative a) = Sum_Negative (f a)
395 fmap f (Sum_Positive a) = Sum_Positive (f a)
396 fmap f (Sum_Both a0 a1) = Sum_Both (f a0) (f a1)
398 instance Balance.Amount a
399 => Balance.Amount (Sum a) where
400 type Amount_Unit (Sum a) = Balance.Amount_Unit a
403 Sum_Negative n -> Balance.amount_null n
404 Sum_Positive p -> Balance.amount_null p
405 Sum_Both n p -> Balance.amount_null (Balance.amount_add n p)
408 (Sum_Negative n0, Sum_Negative n1) -> Sum_Negative (Balance.amount_add n0 n1)
409 (Sum_Negative n , Sum_Positive p) -> Sum_Both n p
410 (Sum_Negative n0, Sum_Both n1 p) -> Sum_Both (Balance.amount_add n0 n1) p
412 (Sum_Positive p , Sum_Negative n) -> Sum_Both n p
413 (Sum_Positive p0, Sum_Positive p1) -> Sum_Positive (Balance.amount_add p0 p1)
414 (Sum_Positive p , Sum_Both n1 p1) -> Sum_Both n1 (Balance.amount_add p p1)
416 (Sum_Both n0 p0, Sum_Negative n) -> Sum_Both (Balance.amount_add n0 n) p0
417 (Sum_Both n0 p0, Sum_Positive p1) -> Sum_Both n0 (Balance.amount_add p0 p1)
418 (Sum_Both n0 p0, Sum_Both n1 p1) -> Sum_Both (Balance.amount_add n0 n1) (Balance.amount_add p0 p1)
421 Sum_Negative n -> Sum_Positive $ Balance.amount_negate n
422 Sum_Positive p -> Sum_Negative $ Balance.amount_negate p
423 Sum_Both n p -> Sum_Both (Balance.amount_negate p) (Balance.amount_negate n)
425 instance GL.Amount (Sum (Map Unit Amount)) where
426 type Amount_Unit (Sum (Map Unit Amount)) = Unit
429 (Sum_Negative n0, Sum_Negative n1) -> Sum_Negative (GL.amount_add n0 n1)
430 (Sum_Negative n , Sum_Positive p) -> Sum_Both n p
431 (Sum_Negative n0, Sum_Both n1 p) -> Sum_Both (GL.amount_add n0 n1) p
433 (Sum_Positive p , Sum_Negative n) -> Sum_Both n p
434 (Sum_Positive p0, Sum_Positive p1) -> Sum_Positive (GL.amount_add p0 p1)
435 (Sum_Positive p , Sum_Both n1 p1) -> Sum_Both n1 (GL.amount_add p p1)
437 (Sum_Both n0 p0, Sum_Negative n) -> Sum_Both (GL.amount_add n0 n) p0
438 (Sum_Both n0 p0, Sum_Positive p1) -> Sum_Both n0 (GL.amount_add p0 p1)
439 (Sum_Both n0 p0, Sum_Both n1 p1) -> Sum_Both (GL.amount_add n0 n1) (GL.amount_add p0 p1)
443 => amount -> Sum amount
445 case ( sumable_negative amt
446 , sumable_positive amt ) of
447 (Just n, Nothing) -> Sum_Negative n
448 (Nothing, Just p) -> Sum_Positive p
449 (Just n, Just p) -> Sum_Both n p
450 (Nothing, Nothing) -> Sum_Both amt amt
453 :: Sum amount -> Maybe amount
456 Sum_Negative n -> Just n
457 Sum_Positive _ -> Nothing
458 Sum_Both n _ -> Just n
461 :: Sum amount -> Maybe amount
464 Sum_Negative _ -> Nothing
465 Sum_Positive p -> Just p
466 Sum_Both _ p -> Just p
470 => Sum amount -> amount
475 Sum_Both n p -> GL.amount_add n p