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.
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.
I dropped these last month, perhaps without meaning to.
They probably should stay. hledger-ui (eg) will still build
with minor updates of hledger-lib or hledger, but will require
either a release or a hackage revision to build with a major
update.
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).
hledger-lib had a valid install plan with GHC 7.8, but requires GHC 7.10 to compile (currently).
Require base 4.8+ everywhere so that stack/cabal will enforce a supported GHC version early.
Also, bump hledger-ui's "stability" to "stable".
