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    (Possible) Breaking change: local variables references inside nested function definitions

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    • d.healeyD
      d.healey @Christoph Hart
      last edited by

      @Christoph-Hart Thanks for the fast work!

      Libre Wave - Freedom respecting instruments and effects
      My Patreon - HISE tutorials
      YouTube Channel - Public HISE tutorials

      Christoph HartC 1 Reply Last reply Reply Quote 0
      • Christoph HartC
        Christoph Hart @d.healey
        last edited by

        Now that I'm currently in "fixing annoying things in the HiseScript compiler" mode, I also fixed leaking of iterator variables into the global namespace:

        inline function inner()
        {
            for(i = 0; i < 10; i++)
                Console.print(i);
        } 
        
        function outer()
        {
            for(i = 0; i < 5; i++)
                inner();
        }
        
        Console.print(i);
        

        This will have rather unpredictable results because the i in the inline function is actually using the same scope as the one in the outer function, which will leak also to the global scope. In order to fix this, you previously needed to declare local / var statements before the loop like this:

        inline function inner()
        {
            local i = 0;
        
            for(i = 0; i < 10; i++)
                Console.print(i);
        } 
        
        function outer()
        {
            var i = 0;
        
            for(i = 0; i < 5; i++)
                inner();
        }
        
        Console.print(i);
        

        Which I've grown accustomed to do whenever I was using these kind of generic loop iterator names that might be called in a nested fashion. However that shouldn't be the responsibility of the user but a language feature, so I've added some code to the compiler to actual inject these local / var statements before the for loop so it makes sure it uses the most narrow scope possible when using iterator variables.

        d.healeyD ustkU 2 Replies Last reply Reply Quote 2
        • d.healeyD
          d.healey @Christoph Hart
          last edited by

          @Christoph-Hart That's nice, I've been in the same habit of declaring local versions

          Libre Wave - Freedom respecting instruments and effects
          My Patreon - HISE tutorials
          YouTube Channel - Public HISE tutorials

          1 Reply Last reply Reply Quote 0
          • ustkU
            ustk @Christoph Hart
            last edited by

            @Christoph-Hart Can't capture anonymous expression

            Might be just normal, I'm not familiar enough with lambdas...

            for (t in things)
            {
            	bgPnl.setPaintRoutine(function [t](g){}); // Can't capture anonymous expressions
            
            	var thing = t;
            	bgPnl.setPaintRoutine(function [thing](g){}); // ok
            }
            

            Just for my personal knowledge, why is it anonymous?

            Can't help pressing F5 in the forum...

            d.healeyD Christoph HartC 2 Replies Last reply Reply Quote 0
            • d.healeyD
              d.healey @ustk
              last edited by d.healey

              @ustk t is anonymous, as in you didn't declare it. HISE just magicked it out of a nowhere when you needed it for your loop. What about this approach?

              function myPaintRoutine(g)
              {
                  var things = this.data.things;
              }
              
              bgPnl.data.things = things;
              bgPnl.setPaintRoutine(myPaintRoutine); 
              

              Libre Wave - Freedom respecting instruments and effects
              My Patreon - HISE tutorials
              YouTube Channel - Public HISE tutorials

              ustkU 1 Reply Last reply Reply Quote 1
              • ustkU
                ustk @d.healey
                last edited by

                @d-healey Thanks for clarifying
                Yeah, I can find a way to o what I need, it's just that for once I could find a purpose for using lambdas, disillusion... :)

                Can't help pressing F5 in the forum...

                d.healeyD 1 Reply Last reply Reply Quote 0
                • d.healeyD
                  d.healey @ustk
                  last edited by

                  @ustk Here's the kind of thing I use lambdas for

                  inline function promptForSomething(name)
                  {
                      Engine.showYesNoWindow("Would you like to view " + name + "?", function [name](response)
                      {
                          if (response)
                              show(name);
                      });
                  }

                  Libre Wave - Freedom respecting instruments and effects
                  My Patreon - HISE tutorials
                  YouTube Channel - Public HISE tutorials

                  ustkU 1 Reply Last reply Reply Quote 1
                  • ustkU
                    ustk @d.healey
                    last edited by

                    @d-healey In fact I'm mistaken as I used it in another project the same way you do:

                    inline function ondriverCbControl(component, value)
                    {
                    	Engine.showYesNoWindow(Titles.ChangeDriver, Messages.WarningDeleteCaptures, function[value](result)
                    	{
                    		if (result)
                    		{
                    			Settings.setAudioDeviceType(drivers[value-1]);
                    		}
                    	});
                    };
                    driverCb.setControlCallback(ondriverCbControl);
                    

                    But it's the first time I try in a for loop though...

                    Can't help pressing F5 in the forum...

                    1 Reply Last reply Reply Quote 1
                    • Christoph HartC
                      Christoph Hart @ustk
                      last edited by

                      @ustk David is right, the iterator variable is not part of the function scope that can be passed to the lambda. Not sure if this is an oversight or if there is a good reason, but I always create variables like in the second line too. Think of it as picking up a nice bouquet in order to surprise your lambda friend.

                      ustkU 1 Reply Last reply Reply Quote 2
                      • ustkU
                        ustk @Christoph Hart
                        last edited by

                        @Christoph-Hart Love the analogy 🌻 :)

                        Can't help pressing F5 in the forum...

                        Christoph HartC 1 Reply Last reply Reply Quote 0
                        • Christoph HartC
                          Christoph Hart @ustk
                          last edited by

                          @ustk Yeah, it was definitely worth googling what that phrase sounds like in English...

                          ustkU 1 Reply Last reply Reply Quote 0
                          • ustkU
                            ustk @Christoph Hart
                            last edited by

                            @Christoph-Hart bouquet is a french word :)

                            Can't help pressing F5 in the forum...

                            d.healeyD 1 Reply Last reply Reply Quote 0
                            • d.healeyD
                              d.healey @ustk
                              last edited by

                              @ustk https://www.youtube.com/watch?v=FboWtJiNYro

                              Libre Wave - Freedom respecting instruments and effects
                              My Patreon - HISE tutorials
                              YouTube Channel - Public HISE tutorials

                              ustkU Adam_GA 2 Replies Last reply Reply Quote 3
                              • clevername27C
                                clevername27
                                last edited by

                                Some of us were already quite familiar this one. 😭😭😭

                                1 Reply Last reply Reply Quote 0
                                • ustkU
                                  ustk @d.healey
                                  last edited by

                                  @d-healey Oh boy I miss so much that brit humour 🤣

                                  Can't help pressing F5 in the forum...

                                  1 Reply Last reply Reply Quote 0
                                  • Adam_GA
                                    Adam_G @d.healey
                                    last edited by

                                    @d-healey do you think its possible having this in my project is some how causing my note release issue?

                                    d.healeyD 1 Reply Last reply Reply Quote 0
                                    • d.healeyD
                                      d.healey @Adam_G
                                      last edited by

                                      @Adam_G No because that issue is happening in a project without any scripting

                                      Libre Wave - Freedom respecting instruments and effects
                                      My Patreon - HISE tutorials
                                      YouTube Channel - Public HISE tutorials

                                      1 Reply Last reply Reply Quote 0
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