Hi Wayne, This solution is pretty much “property” tokens except that:
1) it’s more flexible (properties can be arbitrary s-expressions) 2) it handles 3rd-party-needs and our own with a single infrastructure I was going to add (3) it requires name-spacing, but “property” tokens will require name spacing anyway (to keep 2 different 3rd parties from colliding). The only difference is that we get the default name-space to ourselves. In fact, I think the “property” angle is a much better angle to look at it from. Rather than think of it as a file-format issue, think of it as s-expression meta-data for BOARD_ITEMS. If we later decide that "(hole-to-hole-clearance 0.25)" should define a distance used by DRC, then great. Until then, it’s just an opaque s-expression. I also think it demonstrates that the risk of wiping out stuff editing a future board with an older version isn’t really there. Just like “properties”, we’ll round-trip whatever meta-data was in the board. Sure, new BOARD_ITEMS that you add won’t have the future data, but why would they? (And if we remain concerned José’s force-save-as solution is an excellent idea.) The code complexity it adds to the parser is tiny. It turned out to be far easier to implement than anticipated. Cheers, Jeff. > On 20 Mar 2018, at 14:48, Wayne Stambaugh <[email protected]> wrote: > > Jeff, > > I wanted some time to think about this. It has been discussed before. > While I'm not completely opposed to it, I still haven't found a more > compelling argument to convince me that it is a better idea than using > strict parsing. As a user, it does have a certain appeal. As a > developer, it opens a Pandora's box of issues that once they are in > play, could be extremely difficult to reverse. Please see my responses > below. > > On 3/20/2018 9:40 AM, Jeff Young wrote: >> @Wayne, did you have any thoughts on this iteration? >> >>> On 20 Mar 2018, at 10:22, Jeff Young <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> Oh, and I don’t think this materially alters the support equation: we >>> already have to deal with hand-edited boards, so what’s in the file is >>> never guaranteed to be something Kicad put there. > > True, but this is one of the reasons that the board parser is strict. > It is immediately obvious what doesn't belong in the file. Also, in the > past users have tricked eeschema and pcbnew into a feature that didn't > technically exist by taking advantage of the loose file parsing. Then > when something changed internally and their clever hacks were broken, we > ended up with bug reports. I do not want to repeat this again. > >>> >>>> On 20 Mar 2018, at 10:19, Jeff Young <[email protected] >>>> <mailto:[email protected]>> wrote: >>>> >>>> Hi Seth, >>>> >>>> The original version spit out log entries for skipped elements. This >>>> version follows the XML/browser convention of silently ignoring. >>>> Even though this isn’t an XML format, I think we need to recognise >>>> that we live in an XML world and XML processing conventions set >>>> expectations. > > After reading this, I am even more thankful that we didn't choose XML > for our file format. Gleefully ignoring file syntax that the parser > doesn't understand IMO is a bad idea. This flies in the face of the > basic premise that we control the format of our files not someone else. > As soon as you allow others to dictate your file format, you are in trouble. > >>>> >>>> The patch strictly checks everything for round-tripping so that there >>>> is no data loss. The pad stuff is really a separate issue: it was >>>> meant to be loose only during development and then tightened up, but >>>> the tightening step was forgotten. Since we don’t store pad stuff we >>>> don’t understand, it has to be tightened. In short: if you can round >>>> trip stuff you don’t understand then do so; otherwise throw. > > The round tripping is fine and makes sense but it also adds to the code > complexity of the parser. The pad issue is different. I don't know > when that was slipped into the parser but it should not be there. If > there is an unexpected token, that should flag a file load error. > >>>> >>>> Certainly one use case is opening boards from future versions. If >>>> you edit them, then you’re at your own peril. This behaviour is >>>> common enough that I believe it is well understood (although we >>>> should obviously mention it in a version-check dialog). > > Perhaps, but I just see this ending badly. Maybe I'm being paranoid > here but it's so easy to imagine a scenario where someone did a lot of > editing in a newer version of kicad then makes the fatal mistake of > opening the board in an older version of kicad and wipes out a lot of > work. Technically not kicad's fault but I'm not so sure the user will > see it that way. > >>>> >>>> Another use case is 3rd-party tools (which might even be written as >>>> Python plugins) that want to carry their own stuff around in the >>>> board. These might even be processing/manufacturing instructions >>>> that don’t have any visual expression in Kicad anyway. > > This is one of the primary reasons that I do not like ignoring unknown > file formatting. It creates the potential for name space pollution that > could cause issues down the road. The eventual goal is to implement the > "property" token to define key/value pairs for third party applications > to add user specific information to any board object without polluting > the controlled part of the file format. The beauty of this is that we > do not have to coordinate with 3rd party developers to ensure we are not > clashing with anything the are working on. They are free to add > whatever properties they would like while we still maintain strict file > parsing. This was always part of the grand plan for the board file > format that kind of got lost in the noise and me becoming project leader. > > Cheers, > > Wayne > >>>> >>>> Cheers, >>>> Jeff. >>>> >>>> >>>>> On 19 Mar 2018, at 22:51, Seth Hillbrand <[email protected] >>>>> <mailto:[email protected]>> wrote: >>>>> >>>>> Hi Jeff- >>>>> >>>>> A few questions on how you are implementing this: >>>>> >>>>> 1) How does the user know what was skipped? I can imagine team >>>>> members with different versions getting into difficulty, especially >>>>> if the features being skipped change the board layout. >>>>> >>>>> 2) You are removing strict checking for most of the board but you >>>>> are adding strict checking for pad options. What's the difference? >>>>> >>>>> 3) If we keep these options around but don't allow editing/removing, >>>>> don't we run into a risk of generating a really wonk-y board that >>>>> only looks wonky in a newer version of KiCad but looks fine in an >>>>> older version? For example, imagine we implement rounded corners as >>>>> a parameter and then a user with an older version of KiCad edits and >>>>> saves the board. The rounded corner is only visible in KiCad 6 but >>>>> the user in KiCad 5 can edit the board to look right to her only to >>>>> have her colleague use KiCad 6 and see the track violating DRC. I >>>>> think that might be counter-intuitive for users but maybe there's a >>>>> way around it. >>>>> >>>>> In general, if I understand the use-case, this is to allow users to >>>>> open newer boards in older KiCad versions? Is there another use case? >>>>> >>>>> I think I can see clear to this for options like the 3d-model offset >>>>> where it could be either inches or mm but there isn't a difference >>>>> in the actual layout. Allowing general unrecognized options would >>>>> seem to open up a worm can in terms of support as in "Please post >>>>> the KiCad version and the file version in order to figure out the >>>>> problem." >>>>> >>>>> -S >>>>> >>>>> >>>>> >>>>> 2018-03-18 9:46 GMT-07:00 Jeff Young <[email protected] >>>>> <mailto:[email protected]>>: >>>>> >>>>> OK, for your guys’ (re)viewing pleasure, a patch which >>>>> losslessly round-trips stuff it doesn’t understand. >>>>> >>>>> >>>>> >>>>> >>>>>> On 16 Mar 2018, at 19:15, hauptmech <[email protected] >>>>>> <mailto:[email protected]>> wrote: >>>>>> >>>>>> While i would still like to see this (my) shim go in, I agree >>>>>> with wayne. Until/unless a less brittle approach is used for >>>>>> the parser, it's better to signal a problem painfully and >>>>>> maintain the integrity of the file. >>>>>> >>>>>> I have to admit that when i first heard the s-expressions idea >>>>>> I assumed that the intention was to use a lisp like virtual >>>>>> machine for loading and maintaining design data. I've used vm's >>>>>> for data storage before (lua and python), and it's great. >>>>>> Parsing is free and you can jam in functions and other data >>>>>> when needed. >>>>>> >>>>>> >>>>>> >>>>>> On 17 Mar 2018 07:17, "Jeff Young" <[email protected] >>>>>> <mailto:[email protected]>> wrote: >>>>>> >>>>>> Hi Wayne, >>>>>> >>>>>> Patch reverted. >>>>>> >>>>>> However, I think your concern is misplaced. If we want to >>>>>> prevent dataloss (ie: from reading a 6.0 file into 5.0), >>>>>> then we should warn the user based on the version string >>>>>> (and give them a chance to say “I still want to open”). >>>>>> >>>>>> But either way, actually failing to read the file leaves >>>>>> the user in a pickle (especially when it’s easy enough for >>>>>> them to try out a nightly that may very well be ahead of >>>>>> their stable). >>>>>> >>>>>> (And for that reason I think it’s important to put it into >>>>>> 5.0, as otherwise it won’t help until we start making 7.0 >>>>>> file format changes.) >>>>>> >>>>>> Cheers, >>>>>> Jeff. >>>>>> >>>>>>> On 16 Mar 2018, at 18:00, Wayne Stambaugh >>>>>> <[email protected] <mailto:[email protected]>> wrote: >>>>>>> >>>>>>> Jeff, >>>>>>> >>>>>>> Please revert this patch. Any changes to the board file >>>>>> parser and/or >>>>>>> formatter need to be discussed before the changes are >>>>>> committed. It has >>>>>>> been the intention that the board parser be pendantic by >>>>>> design to >>>>>>> prevent data loss by ignoring unknown formatting. >>>>>> Allowing anything >>>>>>> outside of the expected formatting in the board file is >>>>>> not something >>>>>>> that I want to introduce without some discussion. Even >>>>>> should we decide >>>>>>> to accept this patch, I would prefer we put it off until v6. >>>>>>> >>>>>>> That being said, the patch fails to build on windows with >>>>>> following error: >>>>>>> >>>>>>> >>>>>> C:/msys64/home/wstambaugh/src/kicad-trunk/pcbnew/pcb_parser.cpp: >>>>>> In >>>>>>> member function 'void PCB_PARSER::parseUnknown()': >>>>>>> >>>>>> >>>>>> C:/msys64/home/wstambaugh/src/kicad-trunk/pcbnew/pcb_parser.cpp:1269:12: >>>>>>> error: request for member 'LogText' in >>>>>> '__acrt_iob_func(2)', which is of >>>>>>> pointer type FILE* {aka _iobuf*}' (maybe you meant to >>>>>> use '->' ?) >>>>>>> stderr.LogText( msg ); >>>>>>> ^~~~~~~ >>>>>>> >>>>>>> Cheers, >>>>>>> >>>>>>> Wayne >>>>>>> >>>>>>> On 3/16/2018 1:08 PM, Jeff Young wrote: >>>>>>>> Perhaps somewhat germane to this discussion I have >>>>>> removed the strict-format nags from the PCB parser. It now >>>>>> logs warnings to stderr but otherwise ignores structures it >>>>>> doesn’t understand. >>>>>>>> >>>>>>>> I’m not sure that helps hauptmech much as if the file is >>>>>> subsequently written the unknown markup will be lost, but I >>>>>> thought I’d mention it. >>>>>>>> >>>>>>>> Cheers, >>>>>>>> Jeff. >>>>>>>> >>>>>>>>> On 7 Mar 2018, at 20:12, hauptmech <[email protected] >>>>>> <mailto:[email protected]>> wrote: >>>>>>>>> >>>>>>>>> Hi Thomasz, >>>>>>>>> >>>>>>>>> I hope I'm able to address you concerns. I'm stuck >>>>>> using kicad stable in many situations. I brought clearances >>>>>> up for discussion last July but no one moved on it, nor are >>>>>> they required to. Clearance management is a major pain >>>>>> point for me so I wrote a fix. This patch will let us (me >>>>>> and the people I collaborate with) work using version 5, >>>>>> but open and close files written with a version patched >>>>>> with clearance handling code. >>>>>>>>> >>>>>>>>> I believe that code exactly like this will go into >>>>>> version 6. Getting it in earlier makes a huge difference to >>>>>> me, so I'm submitting it. >>>>>>>>> >>>>>>>>> On 07/03/18 23:30, Tomasz Wlostowski wrote: >>>>>>>>>> Hi hauptmech, >>>>>>>>>> >>>>>>>>>> I'm sorry but IMHO we can't accept your patch: >>>>>>>>>> - it changes the file format while we are already in >>>>>> feature freeze. >>>>>>>>>> This is a way too big change to accept for the V5. >>>>>>>>> >>>>>>>>> This patch simply adds tokens to the file format. No >>>>>> clearance data is saved for files that use the netclass >>>>>> only. Files without clearance tokens continue to remain >>>>>> without them. >>>>>>>>> >>>>>>>>> Yes it is a backward compatible file format change, but >>>>>> it does no harm to V5 files already in the wild. >>>>>>>>> >>>>>>>>>> - we are planning to overhaul the clearance/design >>>>>> rules system in V6. >>>>>>>>>> Storing the clearance *DIRECTLY* for each track >>>>>> segment/via will >>>>>>>>>> conflict with any more sophisticated design rule >>>>>> management system. >>>>>>>>>> >>>>>>>>> I'm glad you are planning this. I am sure that >>>>>> regardless of the sophistication of the rule system, you >>>>>> will store clearance directly for exactly the same reason >>>>>> that track width is stored directly now. There are always >>>>>> exceptions to the rules. >>>>>>>>> >>>>>>>>> If kicad choose a direction that does not store >>>>>> clearances per item, then it is easy to rip these few lines >>>>>> back out. >>>>>>>>> >>>>>>>>> Did this answer your existing concerns about this >>>>>> patch? Are there any other concerns you have about this patch? >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> _______________________________________________ >>>>>>>>> Mailing list: https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>>>> Post to : [email protected] >>>>>> <mailto:[email protected]> >>>>>>>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>>>> More help : https://help.launchpad.net/ListHelp >>>>>> <https://help.launchpad.net/ListHelp> >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Mailing list: https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>>> Post to : [email protected] >>>>>> <mailto:[email protected]> >>>>>>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>>> More help : https://help.launchpad.net/ListHelp >>>>>> <https://help.launchpad.net/ListHelp> >>>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Mailing list: https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>> Post to : [email protected] >>>>>> <mailto:[email protected]> >>>>>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>>> More help : https://help.launchpad.net/ListHelp >>>>>> <https://help.launchpad.net/ListHelp> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Mailing list: https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>> Post to : [email protected] >>>>>> <mailto:[email protected]> >>>>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>>>> <https://launchpad.net/~kicad-developers> >>>>>> More help : https://help.launchpad.net/ListHelp >>>>>> <https://help.launchpad.net/ListHelp> >>>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Mailing list: https://launchpad.net/~kicad-developers >>>>> <https://launchpad.net/~kicad-developers> >>>>> Post to : [email protected] >>>>> <mailto:[email protected]> >>>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>>> <https://launchpad.net/~kicad-developers> >>>>> More help : https://help.launchpad.net/ListHelp >>>>> <https://help.launchpad.net/ListHelp> >>>>> >>>>> >>>> >>>> _______________________________________________ >>>> Mailing list: https://launchpad.net/~kicad-developers >>>> Post to : [email protected] >>>> <mailto:[email protected]> >>>> Unsubscribe : https://launchpad.net/~kicad-developers >>>> More help : https://help.launchpad.net/ListHelp >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~kicad-developers >>> Post to : [email protected] >>> <mailto:[email protected]> >>> Unsubscribe : https://launchpad.net/~kicad-developers >>> More help : https://help.launchpad.net/ListHelp >> >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~kicad-developers >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~kicad-developers >> More help : https://help.launchpad.net/ListHelp >> > > _______________________________________________ > Mailing list: https://launchpad.net/~kicad-developers > Post to : [email protected] > Unsubscribe : https://launchpad.net/~kicad-developers > More help : https://help.launchpad.net/ListHelp
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