Path: utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!cornell!rochester!PT.CS.CMU.EDU!K.GP.CS.CMU.EDU!lindsay
From: lindsay@K.GP.CS.CMU.EDU (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: C machine
Message-ID: <554@PT.CS.CMU.EDU>
Date: 20 Dec 87 21:48:52 GMT
References: <261@ivory.SanDiego.NCR.COM> <164@sdeggo.UUCP> <3078@phri.UUCP>
Sender: netnews@PT.CS.CMU.EDU
Organization: Carnegie-Mellon University, CS/RI
Lines: 23
Keywords: nul terminated strings

There isn't any "right" string representation. But, there are things 
worth saying.

Nul terminated strings: useful, simple.

Length count at front: overhead, but some operations (like concatenation or
block transfer) become easier.

Dope vector: (i.e. a pointer to the string, with length count attached to
the pointer, not to the string): more overhead, but some more operations
are eased. (Substring can be done in-place, with no moved characters.)

For example, suppose you want to read an entire text file to memory, and
then treat it as strings. It makes no sense to copy it piecemeal. So, build
dope vectors that point into the text region. Since you haven't written into
the stuff, you can easily put big chunks out to another file.

"All problems in computer science can be solved by adding layers of
indirection" - old joke.

We knew all this stuff years ago, so please, no rebuttals.
-- 
	Don		lindsay@k.gp.cs.cmu.edu    CMU Computer Science