Bernard,
Just on the language. I get your meaning. English uses "identical" or
"equivalent", if necessary qualified with "exactly" or "precisely" to denote
literal equivalence. Dutch is formally more close to German ( "het zelfde"
(= generally the same) or identiek (=identical). "Gleich" translates as
"gelijk")
On Oberon/Pascal etc. Generally I subscribe to the notion of named type
equivalence, but in practice it's cumbersome. MODULA-3 was more pragmatic
but seems to have fallen by the wayside.
Thanks again, Bart
-----Original Message-----
From: Treutwein; Bernhard
[mailto:Bernhard.Treutwein{([at]})nowhere.xy
Sent: Wednesday, December 12, 2001 7:27 AM
To: Wijck, Bart van
Subject: RE: Why always open array as parameter?
> From: "Wijck, Bart van" <Bart_van_Wijck{([at]})nowhere.xy
> To: "'Treutwein; Bernhard'"
<Bernhard.Treutwein{([at]})nowhere.xy
> Subject: RE: Why always open array as parameter?
> Date: Tue, 11 Dec 2001 15:44:44 +0100
> It does, but that makes it even weirder to understand.
> Why does it matter if one declares them as one specified
> type or as two identical types?????
>
I could not reply yesterday, but you're correct.
From a human program reader viewpoint, it is
immediately clear that the variable and the
parameter are declared as the same type.
From a compiler (writer's) viewpoint, both
are mapped on different anonymous types,
which make assignement and comparison
difficult.
This behaviour has been in almost all
original Wirth languages (I don't know
for shure about Algol-W), but I'm shure
about Pascal, Modula & Oberon. Wirth
is/was very curious about compiler
simplicity & efficiency. It was relaxed
in many commercial implementations
of extensions of these languages.
BTW: given your name and supposed
location by the email address, there is
some chance that either you understand
german or dutch has a similar construct
as "das selbe" and "der gleiche" an
differenciation which seems to be
not existant in english - at least
dict.leo.org does not reveal it.
But if you understand it, "derselbe" type
refers to the compiler's viewpoint and
"dergleiche" to the human reader's
viewpoint.
regard & have a nice day
Bernhard Treutwein
Bernhard.Treutwein{([at]})nowhere.xy
Tel. 049-89-2180-2774 Fax.: 089-2180-9927742
Received on Wed Dec 12 2001 - 08:56:15 UTC