Bison diagnostics

[Hans Aberg]

Bison's diagnostics are somewhat inconsistent: In common compiler lingo, an
"error" is a dignostic, means no compiler output can be generated, and a
warning is a diagnostic which does not in itself terminate compiler output.
(In addition, my compiler has "information".) But Bison has both "errors"
and "fatal errors", in addition to warnings. (Bison does not use the
function complain(), only complain_at().) So what is the difference between
Bison "error" and "fatal error"?.

  Hans Aberg