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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Warning: Religious naming convention discussion :-) [was: assign
 help!!]
Date: 1997/05/14
Message-ID: <dewar.863602865@merv>#1/1
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References: <5kjvcv$evt@news.cis.nctu.edu.tw> <dewar.863365392@merv>
 	<EA1I8o.HBD@world.std.com> <dewar.863448507@merv>
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 <osn2pz4d30.fsf@ted.vigra.com>
Organization: New York University
Newsgroups: comp.lang.ada
Date: 1997-05-14T00:00:00+00:00
List-Id: <comp.lang.ada>


David Brown said

<<Probably because the notation in C:

        foo[bar]

is semantically equivalent to

        *(foo + bar)>>

Robert replies

Actually this is not nearly so "bad" as you might think, as I pointed out
in an earlier reply.
A pointer in C is a structured value with two parts
A reference to the base (in this case the array foo), and an offset
in storage units.

Pointer arithmetic adjusts the storage unit offset to correspond to the
appropriate number of typed components (i.e. in Ada terms component_size
is equal to the type'size, and the offset is adjsuted by bar * component_size.

So really one could say that *(foo + bar) is simply a shorthand for
foo[bar] rather than the other way round!