🚀 go-pugleaf

   [lots of articles complaining about the fact that you can't
   change top-level bindings in ML]

For example, wg@opal.cs.tu-berlin.de writes:
   Or is there someone working professional with SML who takes advantage of
   the interactive system? Personal (relatively little) experiences with the
   SML environment is that one soon writes batch files to work around it.

I use SML interactively: source files in one (Emacs) window, SML in
another window. I usually have one source file in which I write and
debug new functions, and, eventually, they get wrapped up into a new
module. Working this way, I usually only have to recompile the
function I'm currently debugging (C-c C-c). If I have to fix older
functions, I simply recompile the whole file (C-c C-u), or recompile
them in the right order. This is not very different from CommonLisp
development.

I like the behavior of the SML top-level. I think any attempt at
allowing the user to change the binding, or, worse yet, type of an
already existing binding, would introduce lots of complications and
make the top-level much harder to understand. It would also keep the
compiler from making lots of optimizations that it currently can make.

If recompilation speed really turns out to be an issue, an
implementation of SML could, within the current language semantics,
record dependencies during the first compilation and avoid
recompilation of unchanged and independent values even if you just
told it "compile everything".

Better compilers, not worse semantics, are the answer to this issue.