code development

[Stephen Weeks]

> If I run `mlton -v', then it says
> 	keep diagnostics: []
> but nothing about how to set the flag.  If I say
> 	mlton -v -z
> then it says
> 	invalid switch: -z
> In the man page there is no mention of -z or any -diag flag.
> This is with mlton-20011006-1.  What am I missing?

Once again: expert options are not documented.  And if you look
underneath the "invalid switch: -z", you will see

    -diag pass                      keep diagnostic info for pass