Path: utzoo!mnetor!uunet!husc6!necntc!ima!johnl
From: wucs1!wuibc2!brown@uunet.UU.NET (Michael Brown)
Newsgroups: comp.compilers
Subject: Re: static declarations & accessibility
Message-ID: <811@ima.ISC.COM>
Date: 20 Dec 87 20:54:47 GMT
References: <785@ima.ISC.COM>
Sender: johnl@ima.ISC.COM
Reply-To: wucs1!wuibc2!brown@uunet.UU.NET (Michael Brown)
Organization: Washington University
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In-Reply-To: <792@ima.ISC.COM>

Cc:


In reply to my earlier posting, <792@ima.ISC.COM> Rich Salz states:

> Not a good argument:  it's overruled by the semantics of pointers, and
	.
	.
	.
> Anyhow, the ANSI X3J11 C standardization committee invented (okay, stole
> from C++) the "const" keyword for just that sort of thing.  It's similar
> to the VMS C "readonly" storage-class.  Check out a copy of the draft
> for more info.
> [Similar comments received from several other readers.  -John]

    I wasn't clear enough.  I don't interpret the modifier "static" as meaning
read only but that the declaration is *hidden* from references outside of the
scope of the declaration.

    The motivation for the original question was that if a declaration
is meant to be hidden then why not allow optional runtime protection to force
an error if the hidden declaration is accidentally/un-intentionally referenced
from outside of the context of the declaration.

    I recognize that the static modifier has other uses in addition to
information hiding.

	Regards,
	Mike Brown		Institute for Biomedical Computing
				Washington Univ., St. Louis, MO
				(314) 362-2135
[Not a bad idea, but isn't it really just a special case of pointer checking,
e.g. ensuring that array subscripts point into an array, that a pointer to
foo is really pointing to a foo, and so forth.  Hard to do unless you're
interpreting everything, though.  -John]
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