[CSV rules] Custom field assignment under if statement

[artkpv]

Hi, thanks for this brilliant tool!

Problem How to assign a value to a custom field (not hledger one)? So far it breaks with strange error.

Motivation I've tried to parse a complex csv file from a bank (broker). It has different fields for in and out amounts which can be both non empty (two transactions) and different currencies. Also in my hledger journals I use other symbols for currencies and placement: 1000 D (instead of $1000), i.e. after amount.

My csv file:

agreement	currency		Дата	Операция				Сумма зачисления	Сумма списания	В т.ч.НДС (руб.)	Остаток (+/-)	в т.ч. гарант. обеспечение	в т.ч. депозитная маржа	Площадка		Примечание				Промежуточный клиринг (FORTS)
myaggrementname от 06.04.2020	Рубль		11.06.20	"""Проценты по займам """"овернайт ЦБ"""""""				0.04						ММВБ										

My rules file:

separator TAB

skip 1

fields  aggrement, rc, , date, tname, , , , t_in, t_out

if %rc USD
 mycurrency D

if %rc Рубль
 mycurrency R

if %t_in .+
 amount-in %t_in %mycurrency

if %t_out .+
 amount-out %t_out %mycurrency

Steps to reproduce. Just run

[I] ➜ hledger -f test.csv print --rules-file csv.rules
hledger: user error (csv.rules:8:1:
  |
8 | if %rc USD
  | ^
unexpected 'i'
expecting end of input
)

Misc. hledger 1.17.1.1 (The same under 1.18)