(unknown charset) Re: [BLACKBOX] Read-only IN parameters for all data types

From: (unknown charset) Oleg N. Cher <"Oleg>
Date: Thu, 21 Feb 2008 13:07:24 +0200

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Dear Chris,

>For a new language it certainly could be a choice of IN, CONST, INPUT,
>READONLY, NONMODIFIABLE etc. etc. IN is conveniently short it is also nice
>and symmetrical with OUT. One passes data INto the procedure, the other
>passes data OUT of the procedure.

As fact, CONST is symmetrical with VAR too.

Well, this using of "IN" declares, that parameters are passed INto
a procedure. But it declares nothing about changeability
of the parameters - "IN" usage here does not let to know _intuitively_,
that the parameter further is read only. We can know about
this language feature, but it is impossible to guess.

Btw, intuitivism of Oberon is a strong feature of it.
And we cannot lose this Oberon-style intuitivity, this clearness.

I heard a story about an engineer who did not know any
high level programming language.
Instead of it he knew a few assemblers for microcontrollers.
And, the engineer for the first time has seen the program
written in Pascal, and has cried: " I here understand all! "

And using of CONST for CONSTant (unchanged) parameters is more intuitively,
than using of INto parameters, because we know, that all parameters
are passed INto procedures, even addresses of variables to modify its.

And I wanted to say still, that too often use "IN" will be forgotten,
as Delphi programmers forget (or do not like) CONST using in such way.
Can make to us on the contrary? Changeable parameters let will
marked as "IN", and constant parameters will written simple:

PROCEDURE A (b: INTEGER);

However, it really a question at issue, probably,
I cannot convince you. :-)
That we can make the best - to make own work well enough.


Oleg N. Cher,
Colossoft Research.
allot{([at]})nowhere.xy
2008-02-21

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Received on Thu Feb 21 2008 - 12:07:24 UTC