[plt-scheme] Units implementation: to access imports by indexes

Hello,

Would it have been possible to compile units into e.g. vectors
and to access imports by indexes? In particular, having local aliases
for imports is indispensable? 

Eventually I would like to tweak the current unit implementation so
that members of a compound unit, which belong to different constituent
units, are initialized in a more independent order a la lazy
evaluation. At this moment I am not sure if it is feasible at all, but
it seems access by indexes is more handy for my goal. 

Best regards,
Keiko