Re: Lilypond error behaviour

[David Kastrup]

Andrew Bernard <address@hidden> writes:

> So gentlemen, since this is a regular source of confusion,

You are the first to have complained.

> and it certainly has had me glued up for many days wondering what is
> wrong with my code, should this not be raised as a defect, or at the
> very least the adjetctive ‘fatal’ removed fromt he message, and
> replaced with ‘warning’ or something else?

It is a fatal error in that LilyPond has no idea what you want, and
exits with a fatal error message and an according error state, and
without processing further files on the command line.

I don't see the point in trying to leave a broken PDF file rather than
finishing it.  Some syntax errors are trivial and you want to have a
working PDF file in order to correct as many problems as possible when
every compilation takes half an hour.

> As to lilypond making a best effort at producing output, I have never
> seen this referred to in the NR. That ought to go in somewhere. But
> for my preference, a serious syntax error which is just outright
> garbage should in my opinion not produce any output. Other types of
> compilers would stop.

As does LilyPond.

> If there is such an error it neeeds attention, not PDF output I
> reckon.

If you ignore both error messages as well as error status and just go by
the presence of a PDF file and expect LilyPond to not open the PDF file
unless it can guarantee an error-less rest of the run, then you still
will get confused after editing a file badly by LilyPond leaving the old
PDF file around untouched.

-- 
David Kastrup