We previously had another parser type, 'type ErroringJournalParser =
ExceptT String ...' for throwing parse errors without the possibility of
backtracking. This parser type was removed under the assumption that it
would be possible to write our parser without this capability. However,
after a hairy backtracking bug, we would now prefer to have the option
to prevent backtracking.
- Define a 'FinalParseError' type specifically for the 'ExceptT' layer
- Any parse error can be raised as a "final" parse error
- Tracks the stack of include files for parser errors, anticipating the
removal of the tracking of stacks of include files in megaparsec 7
- Although a stack of include files is also tracked in the 'StateT
Journal' layer of the parser, it seems easier to guarantee correct
error messages in the 'ExceptT FinalParserError' layer
- This does not make the 'StateT Journal' stack redundant because the
'ExceptT FinalParseError' stack cannot be used to detect cycles of
include files
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.
The new version of our package set apparently contains both base-compat and
base-compat-batteries in its transitive closure. This breaks the doctest suite,
which just imports everything into scope when the tests are run, thereby making
module names like Prelude.Compat ambiguous.
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).
When we don't know a file's format, instead of choosing a subset of
readers based on content sniffing, now we just try them all.
Also, LedgerReader is now used only as a last resort,
as it's not yet competitive with JournalReader.
* Replace Parsec with Megaparsec (see #289)
This builds upon PR #289 by @rasendubi
* Revert renaming of parseWithState to parseWithCtx
* Fix doctests
* Update for Megaparsec 5
* Specialize parser to improve performance
* Pretty print errors
* Swap StateT and ParsecT
This is necessary to get the correct backtracking behavior, i.e. discard
state changes if the parsing fails.
The journal/timeclock/timedot parsers, instead of constructing (opaque)
journal update functions which are later applied to build the journal,
now construct the journal directly (by modifying the parser state). This
is easier to understand and debug. It also removes any possibility of
the journal updates being a space leak. (They weren't, in fact memory
usage is now slightly higher, but that will be addressed in other ways.)
Also:
Journal data and journal parse info have been merged into one type (for
now), and field names are more consistent.
The ParsedJournal type alias has been added to distinguish being-parsed
and finalised journals.
Journal is now a monoid.
stats: fixed an issue with ordering of include files
journal: fixed an issue with ordering of included same-date transactions
timeclock: sessions can no longer span file boundaries (unclocked-out
sessions will be auto-closed at the end of the file).
expandPath now throws a proper IO error (and requires the IO monad).
journal files can now include journal, timeclock or timedot files (but
not yet CSV files). Also timeclock/timedot files no longer support
default year directives.
The Hledger.Read.* modules have been reorganised for better reuse.
Hledger.Read.Utils has been renamed Hledger.Read.Common and holds
low-level parsers & utilities; high-level read utilities have moved to
Hledger.Read.
The Journal, Timelog and Timedot readers' detectors now check
each line in the sample data, not just the first one. I think
the sample data is only about 30 chars right now, but even so
this fixed a format detection issue I was seeing.
Timedot is a plain text format for logging dated, categorised
quantities (eg time), supported by hledger. It is convenient for
approximate and retroactive time logging, eg when the real-time
clock-in/out required with a timeclock file is too precise or too
interruptive. It can be formatted like a bar chart, making clear at a
glance where time was spent.
