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From: firth@sei.cmu.edu (Robert Firth)
Newsgroups: comp.arch
Subject: Re: String lengths
Message-ID: <8442@aw.sei.cmu.edu>
Date: 6 Feb 89 13:33:15 GMT
References: <8876@alice.UUCP>
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Reply-To: firth@bd.sei.cmu.edu (Robert Firth)
Organization: Carnegie-Mellon University, SEI, Pgh, Pa
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In article <8876@alice.UUCP> dmr@alice.UUCP writes:

["strings" in C]

>Given the explicit use of character arrays, and explicit pointers to
>sequences of characters, the conventional use of a terminating
>marker is hard to avoid.  The history of this convention and
>of the general array scheme had little to do with the PDP-11; it
>was inherited from BCPL and B.

A correction here: the C scheme was NOT inherited from BCPL.
BCPL strings are not confused with character arrays; their
implemetation is not normally visible to the programmer, and
their semantics are respectably robust.

Much the most common implementation is the one proposed earlier -
have an initial length count followed by exactly that number
of characters.  Naturally, all characters are legal, including
NUL.

There are several reasons for the C 'design', but that its
perpetrators didn't know any better isn't one of them.