Builds a Transaction transformer based on ModifierTransaction.

Query parameter allows injection of additional restriction on posting match. Don't forget to call txnTieKnot.

>>> runModifierTransaction Any (ModifierTransaction "" ["pong" `post` usd 2]) nulltransaction{tpostings=["ping" `post` usd 1]}
0000/01/01
    ping           $1.00
    pong           $2.00


>>> runModifierTransaction Any (ModifierTransaction "miss" ["pong" `post` usd 2]) nulltransaction{tpostings=["ping" `post` usd 1]}
0000/01/01
    ping           $1.00


>>> runModifierTransaction None (ModifierTransaction "" ["pong" `post` usd 2]) nulltransaction{tpostings=["ping" `post` usd 1]}
0000/01/01
    ping           $1.00


>>> runModifierTransaction Any (ModifierTransaction "ping" ["pong" `post` amount{amultiplier=True, aquantity=3}]) nulltransaction{tpostings=["ping" `post` usd 2]}
0000/01/01
    ping           $2.00
    pong           $6.00

Generate transactions from PeriodicTransaction within a DateSpan

Note that new transactions require txnTieKnot post-processing.

>>> mapM_ (putStr . show) $ runPeriodicTransaction (PeriodicTransaction "monthly from 2017/1 to 2017/4" ["hi" `post` usd 1]) nulldatespan
2017/01/01
    hi           $1.00

2017/02/01
    hi           $1.00

2017/03/01
    hi           $1.00

Extract Query equivalent of mtvalueexpr from ModifierTransaction

>>> mtvaluequery (ModifierTransaction "" []) undefined
Any
>>> mtvaluequery (ModifierTransaction "ping" []) undefined
Acct "ping"
>>> mtvaluequery (ModifierTransaction "date:2016" []) undefined
Date (DateSpan 2016)
>>> mtvaluequery (ModifierTransaction "date:today" []) (read "2017-01-01")
Date (DateSpan 2017/01/01)

DateSpan of all dates mentioned in Journal

>>> jdatespan nulljournal
DateSpan -
>>> jdatespan nulljournal{jtxns=[nulltransaction{tdate=read "2016-01-01"}] }
DateSpan 2016/01/01
>>> jdatespan nulljournal{jtxns=[nulltransaction{tdate=read "2016-01-01", tpostings=[nullposting{pdate=Just $ read "2016-02-01"}]}] }
DateSpan 2016/01/01-2016/02/01