hledger/hledger-lib
Simon Michael 8d75635505 print: limit display precision of generated prices (#262)
When a transaction posts to two commodities without specifying the
conversion price, we generate a price which makes it balance
(cf http://hledger.org/manual.html#prices).

Until now, these generated prices were always shown with full precision
(all available decimal digits) so that a manual calculation with the
displayed numbers would agree.

If there's just one posting in the commodity being priced, we can use an
exact total price and the precision is no problem.

But if there are multiple postings in the commodity being priced, we
must show the averaged unit price. This can be an irrational number,
which with our current Decimal-based implementation would display an
excessive 255 decimal digits. So in this case we now set the price's
display precision to the sum of the (max) display precisions of the
commodities involved. An example:

hledgerdev -f- print
<<<
1/1
    c    C 10.00
    c    C 11.00
    d  D -320.00
>>>
2015/01/01
    c  C 10.00 @ D 15.2381
    c  C 11.00 @ D 15.2381
    d     D -320.00

>>>=0

There might still be cases where this will show more price decimal
places than necessary. For now, YAGNI.
2015-05-27 14:21:19 -07:00
..
Hledger print: limit display precision of generated prices (#262) 2015-05-27 14:21:19 -07:00
tests Add cabal testsuite for hledger-lib. 2013-05-15 15:56:01 -04:00
CHANGES changelogs 2015-05-14 13:39:54 -07:00
hledger-lib.cabal drop regexpr dependency 2015-05-17 08:32:45 -07:00
Hledger.hs promote Hledger.Query to second level 2012-05-16 07:57:10 +00:00
LICENSE split off hledger-lib package, containing core types & utils 2010-03-22 01:44:59 +00:00
Setup.hs Revert "remove Setup.hs files again, fixing a yesod devel warning" 2014-05-24 13:39:09 -07:00