This changes showMixedAmountElided so that the width to elide to is
given as an argument, rather than fixed at 22 characters. This
actually uses the new renderTable interface. Mostly this is just an
internal change, but since we have more information about the widths
of things, we can actually get rid of some superfluous spaces in the
budget report output, previously there to make sure it stayed aligned
with the largest reasonable contents.
This gives renderTable a little more customisation. Before any of the
commits of this PR, render would just receive a string to display in
each cell. After the second commit of this PR it would also receive a
width of the string (in place of stripping ANSI sequences and then
calculating the width). After this commit, it now also takes an
alignment, so you can make cells left or right aligned. The function
render calls renderTable with appropriate options to give the same
behaviour as before. Also, previously render would always put a border
around the table. We would take this output, and would sometimes strip
the border by dropping the first and last rows, and first and last
characters of every row. I've just added an option to control whether
to put the border in, so we can just not add it in the first place,
rather than stripping it later. Note that this is again just defining
helper functions; this extra power is not yet used anywhere.
- for pretty-printing parse errors thrown from the parsing of excerpts
of the source text as if they were thrown from the parsing of the
source text itself
That code fails to compile with ghc-8.6.1 because the instance is undecidable.
I suppose we could enable the appropriate compiler extension to support it, but
I've found that simply removing the instance causes no problems whatsoever: the
entire repository still compiles fine and it passes all test suites, too.
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
- Don't immediately throw custom parse errors into 'ParsecT'; rather,
just construct and return them
- This anticipates the re-implementation of an 'ExceptT' layer of the
parser, which should be able throw custom parse errors
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).
