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Feedback wanted: conditional GCode without indentation

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  • undefined
    fcwilt @bot
    last edited by 8 Feb 2021, 17:21

    @bot said in Feedback wanted: conditional GCode without indentation:

    Keep track of the ENDs the same way one keeps track of the }s.

    '}' symbols are evil incarnate.

    šŸ˜‰

    Frederick

    Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

    undefined undefined 2 Replies Last reply 8 Feb 2021, 17:22 Reply Quote 0
    • undefined
      bot @fcwilt
      last edited by 8 Feb 2021, 17:22

      @fcwilt } // they don't seem so bad to me

      šŸ˜›

      *not actually a robot

      1 Reply Last reply Reply Quote 1
      • undefined
        tekkydave @dc42
        last edited by 8 Feb 2021, 17:28

        @dc42 curly braces for me every time. I don't see the point of adding extra keywords that just take up space.

        ~ tekkydave ~
        D-Bot: 300x300mm | Duet WiFi + Duex2 | 3 independent z motors | X,Y & Z linear rails | E3D Titan Aero + V6 | Precision Piezo z-probe
        FreeCAD, PrusaSlicer

        undefined 1 Reply Last reply 8 Feb 2021, 17:43 Reply Quote 0
        • undefined
          tekkydave @fcwilt
          last edited by 8 Feb 2021, 17:35

          @fcwilt I once used a language called pl/9 that had a repeat...until. I miss it from every other language I've used since.

          ~ tekkydave ~
          D-Bot: 300x300mm | Duet WiFi + Duex2 | 3 independent z motors | X,Y & Z linear rails | E3D Titan Aero + V6 | Precision Piezo z-probe
          FreeCAD, PrusaSlicer

          undefined 1 Reply Last reply 8 Feb 2021, 17:41 Reply Quote 0
          • undefined
            fcwilt @tekkydave
            last edited by 8 Feb 2021, 17:41

            @tekkydave said in Feedback wanted: conditional GCode without indentation:

            @fcwilt I once used a language called pl/9 that had a repeat...until. I miss it from every other language I've used since.

            I never heard of PL/9 - I used PL/1 for a bit - it's looping syntax was flexible and consistent.

            My programming language of choice is Delphi.

            Frederick

            Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

            1 Reply Last reply Reply Quote 0
            • undefined
              fcwilt @tekkydave
              last edited by 8 Feb 2021, 17:43

              @tekkydave said in Feedback wanted: conditional GCode without indentation:

              @dc42 curly braces for me every time. I don't see the point of adding extra keywords that just take up space.

              Keywords have a mnemonic value that isolated arbitrary symbols lack.

              Frederick

              Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

              1 Reply Last reply Reply Quote 0
              • undefined
                garyd9 @dc42
                last edited by garyd9 2 Aug 2021, 17:44 8 Feb 2021, 17:43

                @dc42 said in Feedback wanted: conditional GCode without indentation:

                Does that make the reason for this proposal clearer?

                Yes, much clearer. Thank you.

                I'm not familiar with belt printers and how this might be used - which left (and still leaves) my understanding lacking.

                That being said, can the problem be addressed using macros? Can a print job's gcode use M28/M29 to create new files?

                ; ----- start gcode
                ;
                ; inital printer setup
                ;
                M28 job.gcode ; cause the actual gcode to be written to job.gcode
                ;
                ; ------- actual print gcode generated by slicer
                ;
                ; --------- end gcode
                M29 ; stop/save job.gcode
                ;
                ; -- here would be the loop for running the print job
                while (some_condition)
                ; belt movement
                M32 job.gcode

                <eof>

                (I have no idea if a gcode file can use M28/m29 to create another gcode file, but if it can...)

                "I'm not saying that you are wrong - I'm just trying to fit it into my real world simulated experience."

                1 Reply Last reply Reply Quote 0
                • undefined
                  theruttmeister @dc42
                  last edited by 8 Feb 2021, 17:45

                  @dc42 said in Feedback wanted: conditional GCode without indentation:

                  @garyd9 said in Feedback wanted: conditional GCode without indentation:

                  @fcwilt said in Feedback wanted: conditional GCode without indentation:

                  @garyd9 said in Feedback wanted: conditional GCode without indentation:

                  Can you please give an example of a gcode sequence that would impractical with the current space delimiting blocks?

                  The issue is gcode files as generated by a slicer - not the files you would create yourself on the duet.

                  That doesn't answer the question. Without an example of the problem, it's difficult to give a reasonable opinion on a proposed solution.

                  Suppose you generate a GCode file using a slicer. But you have a belt printer and you want to print it 10 times, with a belt movement between each iteration.

                  Using existing slicers, there is no way to use the slicer start and end scripts to achieve this.

                  You could achieve it by editing the GCode file, but then you would have to indent almost the whole GCode file so that it became the body of the while-loop.

                  If we offer the option to delimit if- and while-commands explicitly, then you could insert one line near the start of the file (the 'while' line), and one near the end (the 'end' line). You might even be able to put the 'while' line in your slicer start script, and the 'end' line in the end script, so that you don't need to edit the file at all.

                  Does that make the reason for this proposal clearer?

                  That could be simplified down to a gcode command that executed a specific .gcode file multiple times:
                  Mxxx thisprintjob.gcode S10
                  For example.
                  That has the advantage of not needing anything like the complexity of conditionals.

                  I think the fact that it is a programming loop is making people think that the solution is to create the ability in g-code to code loops. Where as in fact for the described use case at least, its not really a loop, its just a way to not have the file be 10 times longer than it needs to be.

                  At there other things that actually are conditional and not just 'do x, y number of times'?

                  (in fact, all this could be done in DWC... which in some ways makes more sense).

                  Isolate, substitute, verify.

                  undefined 1 Reply Last reply 8 Feb 2021, 19:16 Reply Quote 0
                  • undefined
                    zapta @fcwilt
                    last edited by 8 Feb 2021, 17:51

                    @fcwilt said in Feedback wanted: conditional GCode without indentation:

                    '}' symbols are evil incarnate.

                    The Duet's firmware is full of them, don't bring it into your home. šŸ˜‰

                    https://github.com/Duet3D/RepRapFirmware/blob/dev/src/Movement/DriveMovement.cpp

                    undefined 1 Reply Last reply 8 Feb 2021, 19:13 Reply Quote 0
                    • undefined
                      garethky
                      last edited by 8 Feb 2021, 18:11

                      1. end is fine
                      2. I would pick just 1 way to do it, even if that way breaks existing code. Now is the time to make breaking changes. I don't want to imagine a) what tricky things users will think up to fool themselves b) what implementation bugs will arise due to the complexity of having 2 ways to do it.
                      3. As a software engineer, this question makes my skin crawl. I really wouldn't do anything for whole files, just blocks. But if you really want to mix both styles, I would do this: require unintended blocks to have a begin and end keywords, on their own lines, to delimit the block. That way begin/end can be used with all of the existing block types without renaming them (the names are perfectly good as-is).
                      if foo == bar
                      begin
                      ; begin unruly slicer generated gcode
                      G10
                      G1 X50 Y50 F5000
                      ; and so on ...
                      end

                      This is basically a friendlier versions of parens{<block>}. You could also postfix the if statement with python's : to indicate an unintended block start but this is so subtle and easy to miss that I think it is visiting an evil on the intended audience.

                      Visual Basic has "OrElse" and "AndAlso", because they refused to re-define the meaning of "or" and "and". Don't be Visual Basic.

                      1 Reply Last reply Reply Quote 0
                      • undefined
                        fcwilt @zapta
                        last edited by 8 Feb 2021, 19:13

                        @zapta said in Feedback wanted: conditional GCode without indentation:

                        The Duet's firmware is full of them, don't bring it into your home. šŸ˜‰

                        That's why I perform a ritual "cleansing" of the boards before I use them in a printer.

                        Better safe than sorry. šŸ˜‰

                        Frederick

                        Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

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                        • undefined
                          fcwilt @theruttmeister
                          last edited by 8 Feb 2021, 19:16

                          @theruttmeister said in Feedback wanted: conditional GCode without indentation:

                          That could be simplified down to a gcode command that executed a specific .gcode file multiple times:
                          Mxxx thisprintjob.gcode S10

                          That would still require editing the slicer generated file to separate out the pre-print/post-print code from the main body of the code.

                          With a While and End you add two lines to the file and your done.

                          Frederick

                          Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

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                          • undefined
                            BoA
                            last edited by BoA 2 Aug 2021, 20:21 8 Feb 2021, 19:27

                            Should the keywork be 'end', or something else?
                            I think I would use

                            if condition
                            then
                            if given condition true
                            execute all commands up to else statement
                            or to fi if there is no else statement
                            else
                            if given condition false
                            execute all commands up to fi
                            fi

                            and

                            while condition
                            do
                            command1
                            command2
                            command3
                            done

                            Should it be permitted to mix keywork-delimiting and indentation-delimiting in the same file? If so, what problems might arise, and what restrictions should be enforced?

                            IMO indentations should be allowed just to keep it more readable, but ignored in processing code

                            How should the user indicate to the firmware that a loop or conditional is to be delimited by a keyword instead of by indentation? One option is to have a new command keyword (e.g. 'noblockindent') that means that for the remainder of the file, keywork-delimiting will be used. Using that keyword when already inside a block would probably have to be banned. Another option is to use different variations of 'if' and 'while' (e.g. a different keyword or some extra character) to indicate keywork delimiting for that command.

                            I would drop indentations for indicating clode blocks

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                            • undefined
                              MJLew
                              last edited by 8 Feb 2021, 20:02

                              1. The coding language that I use most of the time (Livecode) uses "end repeat" to end a repeat loop, "end if" to end a conditional et cetera. It is very nice in that it does not depend on indents and it is entirely unambiguous. I commend it as a model to follow.

                              2. No. Do not allow mixtures. They will be confusing.

                              3. Ideally you would make the delimiting by keyword and do not support indentation. However, I'm guessing that indentation is already in use, and in that case your idea of something like 'noblockindent' would work rather like M82 and M83 (absolute and relative extruder). Perhaps it should have two keywords 'blockindent' and 'blockwords'.

                              1 Reply Last reply Reply Quote 1
                              • undefined
                                MikeS @fcwilt
                                last edited by 8 Feb 2021, 20:22

                                @fcwilt +1 from me but at the moment {} brackets are used for putting variables from object model into gcode commands.

                                Anyway i think that more similiar the conditional code is to c++ and less to python is for me a big yes....i have no problem with this type of language but i hate having indentation to determine the loop/function start/end.

                                I would give a function its proper "ender" so for example "loop" for while loop and so on.

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                                • undefined
                                  OwenD
                                  last edited by 8 Feb 2021, 20:28

                                  Having come from a Delphi programming background (based on pascal) I'd be inclined to lean towards a similar syntax
                                  Pascal was designed to be easy to read/teach.
                                  Blocks are typically surrounded by begin/end and use the keyword "do"
                                  Indentation is not required but usually used for clarity.

                                  while iterations < 10 do
                                  begin
                                  // do stuff
                                  end

                                  For if statements

                                  if move.axes[0].homed do
                                  begin
                                  echo "axis homed"
                                  end
                                  else
                                  begin
                                  echo "axis is not homed"
                                  end

                                  line ends are usually terminated with a semi colon ; except in nested begin/end blocks as if if else (the outer block must have a ; and the inner must not) but I don't think that is necessary here.
                                  Likewise the do keyword is purely for human readability.

                                  I would not allow mixing of indentation and whatever block format is chosen.

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                                  • undefined
                                    bot
                                    last edited by 8 Feb 2021, 22:52

                                    I don't see the need for a begin keyword. If is the keyword that starts the block.

                                    Perhaps if a keyword is required at the beginning, we could borrow some LUA parlance and use THEN, so that the parser knows when the conditional is over.

                                    *not actually a robot

                                    undefined 1 Reply Last reply 9 Feb 2021, 00:44 Reply Quote 0
                                    • undefined
                                      dbruce.ae05
                                      last edited by 8 Feb 2021, 23:13

                                      I’m going to break with the group. I like the Python style of programming and keeping the indentations. Python is widely used and when writing code on the SBC, most likely a raspberry pi, Python is the natural choice.

                                      undefined 1 Reply Last reply 9 Feb 2021, 00:41 Reply Quote 0
                                      • undefined
                                        fcwilt @dbruce.ae05
                                        last edited by 9 Feb 2021, 00:41

                                        @dbruce-ae05 said in Feedback wanted: conditional GCode without indentation:

                                        I’m going to break with the group. I like the Python style of programming and keeping the indentations. Python is widely used and when writing code on the SBC, most likely a raspberry pi, Python is the natural choice.

                                        You're forgiven your errant ways. šŸ˜‰

                                        Frederick

                                        Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

                                        undefined 1 Reply Last reply 9 Feb 2021, 01:06 Reply Quote 0
                                        • undefined
                                          fcwilt @bot
                                          last edited by 9 Feb 2021, 00:44

                                          @bot said in Feedback wanted: conditional GCode without indentation:

                                          I don't see the need for a begin keyword. If is the keyword that starts the block.

                                          Perhaps if a keyword is required at the beginning, we could borrow some LUA parlance and use THEN, so that the parser knows when the conditional is over.

                                          Well in Delphi if you only have one statement after the condition you don't need the begin/end pair. You use them when you have more than one statement.

                                          I always thought that NOT always requiring begin/end even for one statement was a mistake.

                                          Frederick

                                          Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6

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