factor/extra/bank/bank.factor

70 lines
2.2 KiB
Factor

! Copyright (C) 2008 Alex Chapman
! See http://factorcode.org/license.txt for BSD license.
USING: accessors calendar kernel math math.order money sequences ;
IN: bank
TUPLE: account name interest-rate interest-payment-day opening-date transactions unpaid-interest interest-last-paid ;
: <account> ( name interest-rate interest-payment-day opening-date -- account )
V{ } clone 0 pick account boa ;
TUPLE: transaction date amount description ;
C: <transaction> transaction
: >>transaction ( account transaction -- account )
over transactions>> push ;
: total ( transactions -- balance )
[ amount>> ] map-sum ;
: balance>> ( account -- balance ) transactions>> total ;
: open-account ( name interest-rate interest-payment-day opening-date opening-balance -- account )
[ [ <account> ] keep ] dip "Account Opened" <transaction> >>transaction ;
: daily-rate ( yearly-rate day -- daily-rate )
days-in-year / ;
: daily-rate>> ( account date -- rate )
[ interest-rate>> ] dip daily-rate ;
: transactions-on-date ( account date -- transactions )
[ before? ] curry filter ;
: balance-on-date ( account date -- balance )
transactions-on-date total ;
: pay-interest ( account date -- )
over unpaid-interest>> "Interest Credit" <transaction>
>>transaction 0 >>unpaid-interest drop ;
: interest-payment-day? ( account date -- ? )
day>> swap interest-payment-day>> = ;
: ?pay-interest ( account date -- )
2dup interest-payment-day? [ pay-interest ] [ 2drop ] if ;
: unpaid-interest+ ( account amount -- account )
over unpaid-interest>> + >>unpaid-interest ;
: accumulate-interest ( account date -- )
[ dupd daily-rate>> over balance>> * unpaid-interest+ ] keep
>>interest-last-paid drop ;
: process-day ( account date -- )
2dup accumulate-interest ?pay-interest ;
: each-day ( ... quot: ( ... day -- ... ) start end -- ... )
2dup before? [
[ dup [ over [ swap call ] dip ] dip 1 days time+ ] dip each-day
] [
3drop
] if ; inline recursive
: process-to-date ( account date -- account )
over interest-last-paid>> 1 days time+
[ [ dupd process-day ] ] 2dip swap each-day ;
: inserting-transactions ( account transactions -- account )
[ [ date>> process-to-date ] keep >>transaction ] each ;