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From: fransvo@maestro.htsa.aha.nl (Frans van Otten)
Newsgroups: comp.lang.modula2
Subject: Re: type conversion question
Message-ID: <985@maestro.htsa.aha.nl>
Date: 16 Jun 89 07:56:19 GMT
References: <14226@watdragon.waterloo.edu> <7465@xenna.Encore.COM> <6187@pdn.paradyne.com>
Reply-To: fransvo@htsa.UUCP (Frans van Otten)
Organization: AHA-TMF (Technical Institute), Amsterdam The Netherlands
Lines: 33

Alan Lovejoy writes:

=The other favorite misinterpretation of the definition of the language is
=the nutty idea that providing set types  which can contain more elements 
=than the number of bits in a WORD is "nonstandard."  It is NOT!!!!  PIM2
=says only that implementations are not REQUIRED to support set types which
=can contain more elements than the number of bits in a WORD.  But they are NOT
=FORBIDDEN from doing so.  Any implementation that does not support SET OF CHAR
=is useless for most purposes.  SETs are  almost never used for anything except
=SET OF CHAR.

Niklaus Wirth writes (in pim3, the report, chapter 6.6):

=6.6. Set types
=
=A set type defined as SET OF T comprises all sets of values of its
=base type T.  This must be a subrange of the integers between 0 and
=N-1, or a (subrange of an) enumeration type with at most N values,
=where N is a small constant determined by the implementation, usually
=the computer's wordsize or a small multiple thereof.
=
=$ SetType = SET OF type
=
=The standard type BITSET is defined as follows, where W is a constant
=defined by the implementation, usually the wordsize of the computer.
=
=    BITSET = SET OF [0 .. W-1]

____________________________Down with Li Peng!______________________________
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