Re: Google summer of code

[Derek M Jones]

Akim,

> > The main requirement is to resync so that cascading syntax errors
> > are avoided.  One compiler I worked on did multiple parses, using
> > different combinations of error recovery, looking for the one that
> > parsed the largest amount of input (up to some limit) without
> > generating any other syntax errors.
>
> What was the underlying technology of the parsers?  I guess it was
> LL, right?  Were they written by hand?

It was yacc running under Unix version 7 on a PDP-11 cross
compiled to a mainframe.  Our users only got a few goes at
compiling their code everyday (it was a mainframe batch
environment) and it was very important that the compiler
did its best to generate them some kind of executable so
at least they might be able to try out some parts of the code.

All the best error recovery I have every seen occurs in compilers
running on mainframes.  Not because the cost of renting the software
was an arm and a leg, but because the users got to have so
few goes at compiling in a day.

--
Derek M. Jones                              tel: +44 (0) 1252 520 667
Knowledge Software Ltd                      mailto:address@hidden
Applications Standards Conformance Testing    http://www.knosof.co.uk