Forward declaration of procedural types
lazarus / 21-General

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MarkMLl · 2022-11-16 13:43

I know that there's a correct way of doing this, but I don't know the
correct reference terms for which I apologise in advance.

Given code that looks like this

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i type 
ScpiProc= procedure(scpi: TScpiServer; const command: AnsiString);  
TScpiServer= class(TThread)...    procedure RegisterProc(const
pattern: AnsiString; proc: ScpiProc);...  end;  procedure
scpiDoNothing(scpi: TScpiServer; const {%H-}command:
AnsiString); beginend { scpiDoNothing } ;  
That obviously won't compile, since I'm referring to TScpiServer
before its definition.

I really don't want to have to put the implementation of the procedure
in a derived type or a class helper, since there's likely to be a lot
of these spread over many units.

Is there a reasonably neat way of handling the forward declaration?

MarkMLl

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marcov · 2022-11-16 13:51

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i type 
TScpiServer = class;  ScpiProc= procedure(scpi: TScpiServer; const
command: AnsiString);   TScpiServer= class(TThread)...    procedure
RegisterProc(const pattern: AnsiString; proc: ScpiProc);... 
end;  procedure scpiDoNothing(scpi: TScpiServer; const {%H-}command:
AnsiString); beginend { scpi
Probably needs to be inside the same TYPE block.

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MarkMLl · 2022-11-16 13:55

That's it, thanks very much :-)

MarkMLl