need 'const' string params

[Alexey-T]

  TOAuth2OnAccessToken = procedure(Sender: TObject; AccessToken, RefreshToken, TokenScope: string;
    expires_in: integer) of object;
    procedure InternalGrantAuthorizationCode(Scope: string);    
    procedure InternalImplicitGrant(Scope: string);    
    function Post(URL: string; Params: TStrings; Response: TOAuth2Response): integer;    

you pass string-params BY VALUE (no word 'const'). it is much slower. must use function F(const s: string).

[MWASoftware]

Alexey, I have been pondering as to how to respond to this. It is a matter of programming style and I vary rarely use "const" function parameters in Pascal compared with C++. If only because they aren't really const in the C++ meaning. They just suspend certain run time checks and can result in hard to locate bugs. In this specific case, if an application uses OAuth2 functions more than once each time it is run, then you have to ask: what is it doing? Minor performance gains are unlikely to have much of an impact. I much prefer the code to be "safe" rather than "just a little bit faster". If you are in a tight loop - the yes, this may be worth it - but not here. Reference counted variables, such as strings: all you are really talking about is saving a reference count inc on entry and an internal try..finally and reference count dec on exit. I cannot believe that that will make any measurable performance difference at all, except in the most extreme cases of tight loops - which just is not the case here. Also, you have highlighted a callback. My personal view is that const should never be used here. You are constraining the programmer that writes the callback to treat such parameters as const as well as denying them the opportunity to take advantage of any checks that const will suspend. I do not believe that is correct behaviour for a published API. I appreciate you wanting to give advice, and do not want to appear negative, but I do not want to go down the path you are suggesting. Regards Tony

…

On 25/08/2021 21:30, Alexey T. wrote: |TOAuth2OnAccessToken = procedure(Sender: TObject; AccessToken, RefreshToken, TokenScope: string; expires_in: integer) of object; procedure InternalGrantAuthorizationCode(Scope: string); procedure InternalImplicitGrant(Scope: string); function Post(URL: string; Params: TStrings; Response: TOAuth2Response): integer; | you pass string-params BY VALUE (no word 'const'). it is much slower. must use 'function F(const s: string)`. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#6>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHC7QOLWX7AOEOATW5NQ2FLT6VHHRANCNFSM5CZ44G6A>. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&utm_campaign=notification-email>.

[Alexey-T]

TLDR

the “const” will not make functions less safe. But will make them faster. A little.