[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Query about definition of COMMON data type

A strict reading of the last two paragraphs on page 28 of the Mary Poppins
edition says that STRING is not a subtype of COMMON.  This is because STRING
is (ARRAY STRING-CHAR 1), and STRING-CHAR is neither T nor a subtype of
COMMON.  STANDARD-CHAR is a subtype of COMMON, but STRING-CHAR is not, and
is not necessarily a subtype of STANDARD-CHAR.

I assume this was not intentional, and STRING should be a subtype of
COMMON for the same reason that (ARRAY T) is a subtype of COMMON.  I agree
that STRING-CHAR should not be a subtype of COMMON; that makes sense.