RE : Question on procedure parameters

Hi,

In fact, I am converting existing SUN Pascal code to GNU Pascal. Among this, I have a bunch of utility routines which manipulate strings various ways. Some of them have built-in equivalent in gpc rts or gpc unit, but some others have no equivalent.

Apparently, SUN Pascal is not as strict on VAR parameter types as GNU Pascal. So, I have lots of issues compiling the existing code.

An example of my needs is a procedure similar to UpCaseString in gpc unit, which makes each first letter of each word in a string uppercase:

Procedure UpCaseEachWordFirstLetter(Var S : String200);

Where: Type String80 = Varying[200] Of Char;

This procedure accepts strings of any length (SUN Pascal varying strings) up to 200 characters.

Anyway, I tried the conformant array parameter type and it works perfectly well for my needs (even on type STRING(xx) if you mind).

I forgot conformant arrays usage since I had no need for them for 10 years (with Oregon Pascal).

Thanks

Pascal Viandier

-----Message d'origine----- De : gpc-owner@gnu.de [mailto:gpc-owner@gnu.de] De la part de Frank Heckenbach Envoyé : June 8, 2005 13:34 À : gpc@gnu.de Objet : Re: Question on procedure parameters

Pascal Viandier wrote:

I have a question regarding arrays of characters passed as parameters to procedures.

If I declare:

Type Str40 = Array[1..40] Of Char; Str80 = Array[1..80] Of Char;

Var S40 : Str40; S80 : Str80; S : String(50);

Procedure DoArray(SParam : STRING); ..

Procedure DoArrayVar(VAR SParam : STRING); ...

I can call DoArray with S40, S80 and S as parameter with no problem, but I cannot call DoArrayVar with S40 or S80 (It gives the error: type mismatch

in

argument 1 of 'DoArrayVar' at compilation time). I don't understand why it works when the parameter is not VAR and why it does not work when it is VAR.

Types of `var' parameters have to match exactly `String' is not the same as `array of char'. Value parameters only need to be assignment compatible.

To have DoArrayVar work, I had to remove the parameter type, and assign

the

parameter S to a local variable pointer to a Str80. It works for S40 and

S80

but not anymore for S.

Untyped parameters (if that's what you mean) are a low-level beast better left alone unless strictly needed.

Is there a way to declare a VAR parameter that would accept S40, S80 and

S?

No, they're distinct types. To accept S40 and S80, you could use a conformant array, but S is still different.

I might help explaining what you actually want to achieve and why you think you need to break typing rules.

Frank