Yes the default error display handler. Ok, I'll put this on my list of things to do, and hopefully have a version for review at some point.
On Thu, Mar 13, 2014 at 7:22 PM, Robby Findler <ro...@racket-lang.org> wrote: > You'll want to check DrRacket in both "Debugging" and "No Debugging and > Profiling" mode to see if you're happy with the results (and I can help > change them if you're not happy with them). > > Robby > > > On Thu, Mar 13, 2014 at 8:34 PM, Matthew Flatt <mfl...@cs.utah.edu> wrote: >> >> At Wed, 12 Mar 2014 18:05:03 -0700, Eric Dobson wrote: >> > A common issue I have is that the default error handler does not >> > display error message's exn:srcloc if it has it [...] >> > >> > Is this reasonable to add to the default error handler, and if so do >> > people have suggestions on the format? >> >> You mean the default error display handler, right? >> >> I think this change may be worth a try, but there are many >> exception-generating, exception-handling, and exception-printing >> parameters to worry about, both in their interactions and how they're >> currently used. >> >> For example, does DrRacket use the default error display handler? If >> so, it will start printing source locations that it's already showing a >> different way, and I think that's not what you intend. Or some other >> program harness might be worse off if the default display error handler >> starts showing source locations. Then again, the whole point is that >> you want to change the display of errors. Trying to change some things >> and not changes others --- and having enough extension points to >> accommodate certain combinations of changes and non-changes --- is why >> the existing set of parameters and handlers is complex. I will not be >> surprised if we end up with yet another parameter here. >> >> If the change makes sense, probably the handler should not print the >> first returned source location for `exn:fail:read`, `exn:fail:syntax`, >> and `exn:fail:contract:variable` exceptions --- because that location >> is supposed to be built into the error-message text, unless the >> `error-print-source-location` parameter has a false value. Awkward, I >> know; see the previous paragraph. >> >> The right format is likely to print an extra "<field>: <detail>", >> similar to the way that the default error display handler prints >> context lines (if the `error-context-display-depth` parameter is not >> 0). I imagine that the source-location lines should precede the context >> lines, but follow the exception's error message. >> >> _________________________ >> Racket Developers list: >> http://lists.racket-lang.org/dev > > _________________________ Racket Developers list: http://lists.racket-lang.org/dev
