base-compat-batteries provides the same API across more ghc versions
than base-compat does, at the cost of more dependencies. Eg it exports
Prelude.Compat ((<>)) with ghc 7.10/base 4.8, which we expect.
My belief is that several of our deps already require it so the added
cost is not too great. We should probably go back to base-compat when
possible though, eg when we stop supporting ghc 7.10.
We don't need to import Data.Monoid because Prelude.Compat exports "<>"
already. In fact, importing that module causes build failures:
Hledger/Read/Common.hs:725:62: error:
Ambiguous occurrence ‘<>’
It could refer to either ‘Sem.<>’,
imported from ‘Prelude.Compat’ at Hledger/Read/Common.hs:97:1-39
(and originally defined in ‘Data.Semigroup’)
or ‘Data.Monoid.<>’,
imported from ‘Data.Monoid’ at Hledger/Read/Common.hs:110:1-18
Fixes https://github.com/simonmichael/hledger/issues/794.
This dependency is already expressed conditionally for GHC versions older than
8.0.x, which is the proper way to do it since newer versions have that code in
base already.
It's rare that my deps break their api or that newer versions must be avoided,
and very common that they release new versions which I must tediously
and promptly test and release hackage revisions for or risk falling out
of stackage. Trying it this way for a bit.
Older megaparsec is still supported.
Also cleans up our custom parser types,
and some text (un)packing is done in different places
(possible performance impact).
* added showMarketPrice and Hledger.Data.MarketPrice module
* showMarketPrice implemented using showDate
* attempted to add tests to Hledger.Data.MarketPrice
* moved MarketPrice test to Hledger.Read.JournalReader; fixed documentation on MarketPrice; added MarketPrice module to package.yaml
