These are caught (and lead to exit) in pandoc.hs, but
other uses of Text.Pandoc.App may want to recover in another
way.
Added PandocAppError to PandocError (API change).
This is a stopgap: later we should have a separate constructor
for each type of error.
Also fixed uses of 'exit' in Shared.readDataFile, and
removed 'err' from Shared (API change).
Finally, removed the dependency on extensible-exceptions.
See #3548.
This now contains the Verbosity definition previously
in Options, as well as a new LogMessage datatype that
will eventually be used instead of raw strings for
warnings.
This will enable us, among other things, to provide
machine-readable warnings if desired.
See #3392.
It now lives in IO and gives a proper message + exit
instead of calling 'error'.
We shouldn't be making it easier for people to raise error on
pure code. And this is better for the main application
in IO.
In the latex parser when includes are processed, the text of the
included file is directly included into the parse stream. This caused
problems when there was an error in the included file (and the included
file was longer than the original file) as the error would be reported
at this position.
The error handling tries to display the line and position where the
error occured. It works by including a copy of the input and finding the
place in the input when given the position of the error. In the
previously described scenario, the input file would be the original
source file but the error position would be the position of the error in
the included file.
The fix is to not try to show the exact line when it would cause an
out-of-bounds error.
