Re:Re: Sets.

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3 total messages Started by "THE DOCTOR." Mon, 26 Oct 1987 22:04

#3907

Author: "THE DOCTOR."
Date: Mon, 26 Oct 1987 22:04

15 lines
1549 bytes

Hmmm, perhaps the BitSet should be defined to be a word size, and uses
exclusively for bit twiddeling and implementation specific things.  Then,
I think we would rather need a more abstract set construct.  I still think
the compiler should allocate as many words as necessary to hold the range
which should be expected in the set ( boy, that made a lot of sense ), and
the limit should be infinity, or at least a rather large approximation of
infinity.  The maximum cardinal value supported by the implementation might
be a reasonable approximation to infinity.  If a cardinal is 16 bits, then
such a set, SET OF CARDINAL would only take up 8k bytes, which isn't too
extreme, not even for my old 8 bit system.

I hope the forthcomming standard says something reasonable about sets.

                                                    Tom Ruby
                                                 MSRS002@ECNCDC

Re: Sets.

#3909

Author: Hal Chambers
Date: Tue, 27 Oct 1987 12:11

16 lines
1404 bytes

In article <INFO-M2%87102620254979@UCF1VM> Info-Modula2 Distribution List <INFO-M2%UCF1VM.bitnet@jade.berkeley.edu> writes:
>Hmmm, perhaps the BitSet should be defined to be a word size, and uses
>exclusively for bit twiddeling and implementation specific things.  Then,
>I think we would rather need a more abstract set construct.
...
>                                                    Tom Ruby

This is what I have been saying ever since the day I first encountered
Modula-2.  Since BITSET is explicitly machine dependent it should be
part of the pseudo-module SYSTEM and NOT the default type for sets.

There seems to be almost universal agreement on the desirability of an
abstract data type SET.  The majority of these also seem to agree that
there should be no arbitrary restriction on the size other than MAXCARD.

Hal Chambers

Re: Sets.

#3916

Author: schaub
Date: Sat, 31 Oct 1987 18:35

12 lines
1085 bytes

In article <921@pur-phy>, hal@pur-phy (Hal Chambers) writes:
> This is what I have been saying ever since the day I first encountered
> Modula-2.  Since BITSET is explicitly machine dependent it should be
> part of the pseudo-module SYSTEM and NOT the default type for sets.
> Hal Chambers

That's exactly why we decided to put it into SYSTEM in M2Amiga.
-- 
        //
       //  Markus Schaub
   \\ //   uunet!nuchat!sugar!schaub
    \X/    (713) 523 8422

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