[MIT-Scheme-devel] compiled code safety

[Taylor R Campbell]

Over the past year and a half or so, I've helped a number of students
in 6.034 with Scheme problems, and almost all of the problems were
either (1) that they were working with code handed to them by the TAs
or professors that was compiled without checks, or (2) version
incompatibilities, dating as far back as 1993.  The latter is a
problem to be dealt with on Athena (and I may deal with it myself at
some point in the near future), but the former is probably simply a
consequence of the default values of the compiler flags that specify
whether to generate checks; it would not surprise me if said TAs or
professors don't know anything about the safety flags, but like the
speed of compiled code.

Machines today are much faster than they were twenty years ago; would
it be too terrible a burden on performance for the default values of
COMPILER:GENERATE-TYPE-CHECKS? and COMPILER:GENERATE-RANGE-CHECKS? to
be true?  The student band is built with a checked run-time system
anyway, and programs that need the performance can be compiled with
the flags bound to false anyway.