[Haskell-beginners] Where is hugs (or other) version of gofer modular-interpreter code?

[Larry Evans]

Page 2 of:

http://www.cs.yale.edu/~liang-sheng/popl95.ps.gz

says the source code is at:

  nebula.cs.yale.edu/pub/yale-fp/modular-interpreter

However, that's no longer present.

Since Hugs is the successor to gofer, I was wondering
if anyone could tell me how to get a copy of the
corresponding hugs code.

TIA.

-Larry