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From: g-rh@cca.UUCP (Richard Harter)
Newsgroups: net.lang.c
Subject: Re: Byte order (or you are both wrong)
Message-ID: <7485@cca.UUCP>
Date: Thu, 24-Apr-86 00:34:15 EST
Article-I.D.: cca.7485
Posted: Thu Apr 24 00:34:15 1986
Date-Received: Sat, 26-Apr-86 05:54:57 EST
References: <7046@cca.UUCP> <6578@utzoo.UUCP> <17162@rochester.ARPA> <2568@utcsri.UUCP>
Reply-To: g-rh@cca.UUCP (Richard Harter)
Organization: Computer Corp. of America, Cambridge
Lines: 45
Summary: Representation handling chars, ints, etc.

>In article <17162@rochester.ARPA> crowl@rochester.UUCP (Lawrence Crowl) writes:
>
>CHALLENGE:  Come up with a scheme for representing numbers, and a sorting
>scheme in which numbers sort naturally.  Your scheme must deal with variable
>length character strings and variable size numbers.  That is, you cannot
>requires strings to be padded with nulls, or numbers to be padded with zeros.

Presented without endorsement:

Addressing nomenclature -- big endian (i.e. msb is bit 0, etc.)

Item is divided into five parts:

Part I - sign bit (0 is negative, 1 is postive)

Part II - Size of field size in unary, i.e. string of 1's terminated by 0

Part III - Field size, in binary (Field size is size of field to left of
           implicit decimal point.

Part IV -  Portion of string to left of implied decimal point, encoded in
	   bytes.

Part V  - Portion of string to right of implied decimal point, encoded in
          ternary, using two bits per ternary digit, as follows:

	00   Sentinel, terminating right field
	01   ternary 0
        02   ternary 1
	03   ternary 2

All numbers are represented as ascii characters.

The point of the ternary representation (or something equivalent) is
that it provides for a sentinel for variable length strings that sorts
lexicographically.

If an integer is to be considered as a number and compared in that fashion
it goes in the left field -- if it is to be considered as a character string
it goes in the right field.

	I believe that this representation meets the challenge.
I sincerely hope that I never have to work with it.

	Richard Harter, SMDS Inc.