Safe Haskell	Safe-Inferred
Language	Haskell2010

Haspara.Accounting.Side

Description

This module provides definitions for and functions to work with Debit/Credit dichotomy which is essential to double-entry bookkeeping.

In our concept, we refer to this dichotomy as Side (materialized via Side sum-type) which is either Debit (materialized via SideDebit nullary data constructor) or Dredit (materialized via SideCredit nullary data constructor).

This module provides FromJSON and ToJSON instances for Side as well. Following accounting conventions, we chose the JSON value for Debit as "db", and for Credit as "cr".

Synopsis

data Side
- = SideDebit
- | SideCredit
otherSide :: Side -> Side
sideByAccountKind :: KnownNat precision => AccountKind -> Quantity precision -> Side
normalSideByAccountKind :: AccountKind -> Side

Documentation

data Side Source #

Data definition for encoding the debit/credit indicator.

Constructors

SideDebit
SideCredit

Instances

Instances details

FromJSON Side Source #	`FromJSON` instance for `Side`. `>>>` `:set -XOverloadedStrings``>>>` `Aeson.eitherDecode "\"db\"" :: Either String Side`Right SideDebit `>>>` `Aeson.eitherDecode "\"cr\"" :: Either String Side`Right SideCredit `>>>` `Aeson.eitherDecode "\"hebele\"" :: Either String Side`Left "Error in $: Unkown side indicator: \"hebele\". Expecting one of \"db\" or \"cr\""
Instance details Defined in Haspara.Accounting.Side Methods parseJSON :: Value -> Parser Side # parseJSONList :: Value -> Parser [Side] #
ToJSON Side Source #	`ToJSON` instance for `Side`. `>>>` `Aeson.encode SideDebit`"\"db\"" `>>>` `Aeson.encode SideCredit`"\"cr\"" `>>>` `Aeson.decode (Aeson.encode SideDebit) == Just SideDebit`True `>>>` `Aeson.decode (Aeson.encode SideCredit) == Just SideCredit`True
Instance details Defined in Haspara.Accounting.Side Methods toJSON :: Side -> Value # toEncoding :: Side -> Encoding # toJSONList :: [Side] -> Value # toEncodingList :: [Side] -> Encoding #
Show Side Source #
Instance details Defined in Haspara.Accounting.Side Methods showsPrec :: Int -> Side -> ShowS # show :: Side -> String # showList :: [Side] -> ShowS #
Eq Side Source #
Instance details Defined in Haspara.Accounting.Side Methods (==) :: Side -> Side -> Bool # (/=) :: Side -> Side -> Bool #
Ord Side Source #
Instance details Defined in Haspara.Accounting.Side Methods compare :: Side -> Side -> Ordering # (<) :: Side -> Side -> Bool # (<=) :: Side -> Side -> Bool # (>) :: Side -> Side -> Bool # (>=) :: Side -> Side -> Bool # max :: Side -> Side -> Side # min :: Side -> Side -> Side #

otherSide :: Side -> Side Source #

Gives the other side.

>>> otherSide SideDebit
SideCredit
>>> otherSide SideCredit
SideDebit

sideByAccountKind :: KnownNat precision => AccountKind -> Quantity precision -> Side Source #

Computes the Side by the given AccountKind and the sign of the given Quantity.

The sign of the Quantity is indeed a proxy for whether the event of the Quantity is an increment (+1) or decrement (-1) event.

0 quantities are considered to originate from an increment event. So far, this seems to be a safe assumption that gives us totality in the context of this function.

Note the following mapping as a guide:

Kind of account	Debit	Credit
Asset	Increase	Decrease
Liability	Decrease	Increase
Equity/Capital	Decrease	Increase
Income/Revenue	Decrease	Increase
ExpenseCostDividend	Increase	Decrease

>>> :set -XDataKinds
>>> import Haspara.Quantity
>>> let decrement = mkQuantity (-0.42) :: Quantity 2
>>> let nocrement = mkQuantity 0 :: Quantity 2
>>> let increment = mkQuantity 0.42 :: Quantity 2
>>> fmap (sideByAccountKind AccountKindAsset) [decrement, nocrement, increment]
[SideCredit,SideDebit,SideDebit]
>>> fmap (sideByAccountKind AccountKindLiability) [decrement, nocrement, increment]
[SideDebit,SideCredit,SideCredit]
>>> fmap (sideByAccountKind AccountKindEquity) [decrement, nocrement, increment]
[SideDebit,SideCredit,SideCredit]
>>> fmap (sideByAccountKind AccountKindRevenue) [decrement, nocrement, increment]
[SideDebit,SideCredit,SideCredit]
>>> fmap (sideByAccountKind AccountKindExpense) [decrement, nocrement, increment]
[SideCredit,SideDebit,SideDebit]

normalSideByAccountKind :: AccountKind -> Side Source #

Returns the "normal" side for a given AccountKind.

Note the following mapping as a guide:

Kind of Account	Normal Balance	Negative Balance
Asset	Debit	Credit
Liability	Credit	Debit
Equity	Credit	Debit
Revenue	Credit	Debit
Expense	Debit	Credit