From: Paul Duquennoy <paul.duquennoy@wanadoo.fr>
Subject: Re: Question for the folks who designed Ad
Date: 1999/04/29
Date: 1999-04-29T06:37:54+00:00 [thread overview]
Message-ID: <3727FEB6.6ECEB1F5@wanadoo.fr> (raw)
In-Reply-To: 7g8roe$igd1@svlss.lmms.lmco.com
David Kristola wrote:
>
> In article hjh3@ftp.kvaerner.com, "Tarjei Tj�stheim Jensen" <tarjei.jensen@kvaerner.no> () writes:
> >
> >Robert Dewar wrote :
> >>
> >>In other words:
> >>
> >> a(5)
> >>
> >>is a reference to a mapping, and you want the range value
> >>given the domain value 5. Whether this is implemented by
> >>an array or a function is an implementation detail that
> >>should not affect the syntactic form of reference.
> >
> >
> >What would a(5) := 4; mean then? You cannot assign to a function as far as I
> >know. Which in my opinion voids the function opposition to the common
> >convention of using square brackets for array indices.
> >
> >I don't mind if the function addicts still writes a(5) := 4, if I can write
> >a[5] := 4.
> >
> >Greetings,
> >
> >
> >
>
> a(5).some_value := 4;
>
> Maybe the function a returns a pointer to a record structure...
>
Absolutely, and this is useful. An early version of a package can use an array
to implement a feature, but later it can be changed to a more sophisticated
approach
using a cache (e.g. if there are too many unused entries in the array) without
disturbing the existing code.
It is then clear that the 'a(5)' is a way to access some data, regardless of
its
implementation. Ada allows very minimal impact on the code in such circumstances.
The 'auto-dereferencing' of pointers in Ada (vs '->' in C) also gives more flexibility
to change the implementation from actual data to accesses and vice-versa.
next prev parent reply other threads:[~1999-04-29 0:00 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-04-26 0:00 Question for the folks who designed Ada95 Corey Ashford
1999-04-27 0:00 ` Matthew Heaney
1999-04-27 0:00 ` Matthew Heaney
1999-04-27 0:00 ` Corey Ashford
1999-04-28 0:00 ` Marin David Condic
1999-04-28 0:00 ` Robert A Duff
1999-04-28 0:00 ` Keith Thompson
1999-04-29 0:00 ` Robert A Duff
1999-04-27 0:00 ` Robert Dewar
1999-04-27 0:00 ` Corey Ashford
1999-04-27 0:00 ` Tarjei Tj�stheim Jensen
1999-04-27 0:00 ` Larry Kilgallen
1999-04-27 0:00 ` David Starner
1999-04-27 0:00 ` Robert Dewar
1999-04-27 0:00 ` David Starner
1999-04-28 0:00 ` Samuel Mize
1999-04-28 0:00 ` Robert Dewar
1999-04-28 0:00 ` Tarjei Tj�stheim Jensen
1999-04-28 0:00 ` dennison
1999-04-28 0:00 ` Robert Dewar
1999-04-28 0:00 ` Robert A Duff
1999-04-28 0:00 ` Brian Hanson
1999-04-28 0:00 ` bill
1999-04-29 0:00 ` Robert S. White
1999-04-29 0:00 ` Robert Dewar
1999-04-30 0:00 ` Robert S. White
1999-04-29 0:00 ` Robert Dewar
1999-04-30 0:00 ` Robert S. White
1999-04-30 0:00 ` dennison
1999-04-29 0:00 ` Robert Dewar
1999-04-28 0:00 ` Pat Rogers
1999-04-29 0:00 ` Robert Dewar
1999-04-29 0:00 ` dennison
1999-04-29 0:00 ` Pat Rogers
1999-04-30 0:00 ` Robert Dewar
1999-04-28 0:00 ` Robert Dewar
1999-04-28 0:00 ` Robert A Duff
1999-04-29 0:00 ` Bill Ghrist
1999-04-29 0:00 ` Tarjei Tj�stheim Jensen
1999-04-28 0:00 ` Larry Kilgallen
1999-04-28 0:00 ` Robert A Duff
1999-04-29 0:00 ` Question for the folks who designed Ad David Kristola
1999-04-29 0:00 ` Paul Duquennoy [this message]
1999-04-27 0:00 ` Question for the folks who designed Ada95 Robert Dewar
1999-04-28 0:00 ` Corey Ashford
1999-04-28 0:00 ` Robert Dewar
1999-04-28 0:00 ` Robert A Duff
1999-04-28 0:00 ` Robert Dewar
1999-04-29 0:00 ` Robert A Duff
1999-04-29 0:00 ` Corey Ashford
1999-04-29 0:00 ` Robert Dewar
1999-04-29 0:00 ` Fraser Wilson
1999-04-29 0:00 ` Marin David Condic
1999-04-29 0:00 ` Mark A Biggar
1999-04-30 0:00 ` Tucker Taft
1999-04-29 0:00 ` Tucker Taft
1999-04-30 0:00 ` David Brown
1999-04-29 0:00 ` Geert Bosch
1999-04-29 0:00 ` Corey Ashford
1999-04-27 0:00 ` bill
1999-04-27 0:00 ` Robert Dewar
1999-04-27 0:00 ` Al Christians
1999-04-27 0:00 ` Larry Kilgallen
1999-04-27 0:00 ` Al Christians
1999-04-28 0:00 ` Robert A Duff
1999-04-28 0:00 ` Robert Dewar
1999-04-29 0:00 ` Matthew Heaney
1999-04-29 0:00 ` Robert Dewar
1999-04-29 0:00 ` Jean-Pierre Rosen
1999-04-27 0:00 ` dennison
1999-04-27 0:00 ` Robert Dewar
1999-04-29 0:00 ` Robert A Duff
1999-04-29 0:00 ` Aidan Skinner
1999-04-30 0:00 ` Matthew Heaney
1999-04-27 0:00 ` Samuel Mize
1999-04-27 0:00 ` Samuel Mize
1999-04-27 0:00 ` Robert Dewar
1999-04-28 0:00 ` Samuel Mize
1999-04-28 0:00 ` Samuel Mize
1999-04-28 0:00 ` Corey Ashford
1999-04-28 0:00 ` Robert Dewar
1999-04-29 0:00 ` Corey Ashford
1999-04-29 0:00 ` Robert Dewar
1999-04-29 0:00 ` Fraser Wilson
1999-04-29 0:00 ` Marin David Condic
1999-04-29 0:00 ` Robert Dewar
1999-04-28 0:00 ` Corey Ashford
1999-04-28 0:00 ` Corey Ashford
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