🚀 go-pugleaf

= I would take Dr. Wirth's comment to mean that circular references cannot be
= depended upon as a language feature in any given implementation of Modula-2.
= It is just too bad that we language implementators have to deal with such
= ambiguity in language definitions, especially since it is not a complicated
= issue to define.  Circular imports should be outlawed.
= --
= George Thiruvathukal

I wouldn't be so hasty.  Mutual importation is not frequent but is still
legitimate.  For example, consider an object-oriented system in which
classes are implemented by modules.  It is perfectly legitimate for two
classes to exchange messages and thus, do mutual importation.  It is also
legitimate for each module/class to initialize itself.  However, it still
does not seem practical for either one of the two module to reference the
other during initialization (i.e., each create an instance of the other
during initialization).  Even that may be correct (actually, not lead to
potential nondeterminism) if no reference uses information set at
initialization.

The bottom line is that one should not disparage a construct just because
one does not see a use for it.  This particular construct does lead to
an insecurity, but Modula-2 (for all of its typechecking, et.al) has
many others.

Tom Reid  (Reid@ctc.contel.com)