Re: [vwnc] Parsing in Smalltalk
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Am .10.2018, 20:14 Uhr, schrieb Steffen Märcker <[hidden email]>: > Dear all, > > I have two questions regarding parsing frameworks. > > 1) Do you have any insights on the performance of SmaCC VS Xtreams > Parsing VS PetitParser? > 2) Has anybody started to port PetitParser 2 from Pharo to VW? Is it > worth the effort? > > Sorry for cross-posting, I thought this might interest both communities. > > Cheers, Steffen On Fri, 5 Oct 2018 at 04:47, Steffen Märcker <[hidden email]> wrote: I gave Xtreams-Parsing and PetitParser a shot and like to share my Will you be implementing those "additional verification and normalization steps" ? It seems they have an exponential or power impact on times. cheers -ben |
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#memoized is one of the most efficient and hardest optimizations. It cannot be done efficiently in an automated way. It depends on input. Best way is to identify repeated invocation of the same parser combinator at the same position for a typical input, pp2 has a tooling support for this, I wrote a chapter about #memoized in PP2 [1]. PP2 does the poor-man version of memoization (based on grammar analysis) automatically, just by calling #optimize.
If really needed, provide me with parser and input, I can check and suggest optimizations. There should be no fundamental issue with porting PP2 to VW. As far as I know, there is an automated tool to do so, right? On the other hand, PP is stable and does not change, PP2 is maintained and updated from time to time (mostly adding optimizations), so there might be an overhead of syncing PP2 to VW2. Cheers, Jan [1]: https://kursjan.github.io/petitparser2/pillar-book/build/Chapters/memoization.html On Fri, Oct 5, 2018, 13:26 Steffen Märcker <[hidden email]> wrote: Hi Doru! |
Re: [vwnc] Parsing in Smalltalk
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Dear Jan,
I just tried to use PP2 but ran into two issues: 1. PP2 does not load into Pharo 6.1 stable. 2. I use #- to create character classes but was not able to find the equivalent in PP2 yet. > There should be no fundamental issue with porting PP2 to VW. As far as I > know, there is an automated tool to do so, right? I am not aware of this tool. Can you give me some hints what exactly to look for? Best, Steffen On the other hand, PP > is > stable and does not change, PP2 is maintained and updated from time to > time > (mostly adding optimizations), so there might be an overhead of syncing > PP2 > to VW2. > > Cheers, > Jan > > [1]: > https://kursjan.github.io/petitparser2/pillar-book/build/Chapters/memoization.html > > On Fri, Oct 5, 2018, 13:26 Steffen Märcker <[hidden email]> wrote: > >> Hi Doru! >> >> > I assume that you tried the original PetitParser. PetitParser2 offers >> > the possibility to optimize the parser (kind of a compilation), and >> this >> > provides a significant speedup: >> > https://github.com/kursjan/petitparser2 >> > >> > Would you be interested in trying this out? >> >> Yes, I'd like to give this a shot, too. However, as far as I know, PP2 >> is >> only available for Pharo and not VW, is it? >> >> Speaking of optimizations, I also tried to use memoizing the petit >> parser. >> However, the times got worse instead of better. Is there a rule of thumb >> where to apply #memoized in a sensible way? As far as I understand, >> applying it to the root parser does not memoize subsequent parsers, does >> it? >> >> Kind regards, Steffen >> |
Re: [vwnc] Parsing in Smalltalk
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Steffen Märcker wrote
> 1. PP2 does not load into Pharo 6.1 stable. Can you give more details? IIRC I have PP2 loaded in several 6.1 images. ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Cheers,
Sean |
Re: [vwnc] Parsing in Smalltalk
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> Can you give more details? IIRC I have PP2 loaded in several 6.
I did the following: 1) Download and start Pharo 6.1 stable via the launcher. 2a) Attempt to install PetitParser2 via the CatalogBrowser: "Information There was an error while trying to install PetitParser2. Installation was cancelled." 2b) Attempt to install PP2 via the scripts from GitHub: Metacello new baseline: 'PetitParser2'; repository: 'github://kursjan/petitparser2'; load. Metacello new baseline: 'PetitParser2Gui'; repository: 'github://kursjan/petitparser2'; load. "Could not resolve: [BaselineOfPetitParser2] in [...]" Interestingly, it works in Pharo 7 dev, but there the GUI-Tools won't load because of some issues with their dependencies. I hope this helps. As I am not familiar with Pharo, I'd appreciate any hints. Best, Steffen |
Re: [vwnc] Parsing in Smalltalk
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Steffen Märcker wrote
> I did the following: > 1) Download and start Pharo 6.1 stable via the launcher. > 2b) Attempt to install PP2 via the scripts from GitHub: > Metacello new > baseline: 'PetitParser2'; > repository: 'github://kursjan/petitparser2'; > load. > Metacello new > baseline: 'PetitParser2Gui'; > repository: 'github://kursjan/petitparser2'; > load. This way worked for me in Pharo #60546 (check in World->System->About). What exact Pharo version/OS are you on? 32 or 64-bit ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Cheers,
Sean |
Re: [vwnc] Parsing in Smalltalk
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I am using MacOS 10.13.6 and the 32bit VM:
Pharo 6.0 Latest update: #60546 ... the String in about is wrong, it should be 6.1. I installed it via the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I just noticed, that the sources file is missing from vms/private/6521/, too. Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris <[hidden email]>: > Steffen Märcker wrote >> I did the following: >> 1) Download and start Pharo 6.1 stable via the launcher. >> 2b) Attempt to install PP2 via the scripts from GitHub: >> Metacello new >> baseline: 'PetitParser2'; >> repository: 'github://kursjan/petitparser2'; >> load. >> Metacello new >> baseline: 'PetitParser2Gui'; >> repository: 'github://kursjan/petitparser2'; >> load. > > This way worked for me in Pharo #60546 (check in World->System->About). > What > exact Pharo version/OS are you on? 32 or 64-bit > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > |
Re: [vwnc] Parsing in Smalltalk
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Reading the code of PetitParser, I wonder why PPRepeatingParser
initializes 'max' with SmallInteger maxVal instead of some notion of infinity, like Float infinity (and PP2RepeatingNode as well). If I understand the code correctly, PParser>>min: fails if the number of repetitions exceeds SmallInteger maxVal, doesn't it? Best, Steffen Am .10.2018, 17:10 Uhr, schrieb Steffen Märcker <[hidden email]>: > I am using MacOS 10.13.6 and the 32bit VM: > > Pharo 6.0 > Latest update: #60546 > > ... the String in about is wrong, it should be 6.1. I installed it via > the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I > just noticed, that the sources file is missing from vms/private/6521/, > too. > > Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris <[hidden email]>: > >> Steffen Märcker wrote >>> I did the following: >>> 1) Download and start Pharo 6.1 stable via the launcher. >>> 2b) Attempt to install PP2 via the scripts from GitHub: >>> Metacello new >>> baseline: 'PetitParser2'; >>> repository: 'github://kursjan/petitparser2'; >>> load. >>> Metacello new >>> baseline: 'PetitParser2Gui'; >>> repository: 'github://kursjan/petitparser2'; >>> load. >> >> This way worked for me in Pharo #60546 (check in World->System->About). >> What >> exact Pharo version/OS are you on? 32 or 64-bit >> >> >> >> ----- >> Cheers, >> Sean >> -- >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >> > > |
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In reply to this post by Steffen Märcker
Steffen
I do most of my work using Moose Suite 6.1, which is Pharo 6.1 with a lot of extras, because it comes with the tools I want (PetitParser, PP2 and XMLParser) already loaded. The image is huge, but if that's not a problem for you it could be an easy way to get PP2. Best wishes Peter Kenny -----Original Message----- From: Pharo-users <[hidden email]> On Behalf Of Steffen Märcker Sent: 11 October 2018 16:11 To: [hidden email] Subject: Re: [Pharo-users] [vwnc] Parsing in Smalltalk I am using MacOS 10.13.6 and the 32bit VM: Pharo 6.0 Latest update: #60546 ... the String in about is wrong, it should be 6.1. I installed it via the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I just noticed, that the sources file is missing from vms/private/6521/, too. Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris <[hidden email]>: > Steffen Märcker wrote >> I did the following: >> 1) Download and start Pharo 6.1 stable via the launcher. >> 2b) Attempt to install PP2 via the scripts from GitHub: >> Metacello new >> baseline: 'PetitParser2'; >> repository: 'github://kursjan/petitparser2'; >> load. >> Metacello new >> baseline: 'PetitParser2Gui'; >> repository: 'github://kursjan/petitparser2'; >> load. > > This way worked for me in Pharo #60546 (check in World->System->About). > What > exact Pharo version/OS are you on? 32 or 64-bit > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > |
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In reply to this post by Steffen Märcker
I run PP2 on travis [1], seems Pharo 6.1 loads all configurations, both on linux and mac. Pharo 5, Pharo 6.0 got broken, why is build configuration so hard :'( I don't know, how can I support you. I myself had to gave up on some tools, because I failed to load them. There is no specific reason to use SmallInteger maxVal... and nobody ever thought it might be too little. 'PP2 min: X' fails if there are less repetitions that X. 'PP2 max: X' parses at most X repetitions. ($a asPParser min: 2 max: 3) parse: 'a'. -> Failure ($a asPParser min: 2 max: 3) parse: 'aa'. #($a $a) ($a asPParser min: 2 max: 3) parse: 'aaa'. #($a $a $a) ($a asPParser min: 2 max: 3) parse: 'aaaa'. #($a $a $a) Use $- asPParser for characters, e.g: $- asPParser parse: '-' On Thu, Oct 11, 2018 at 8:13 PM Steffen Märcker <[hidden email]> wrote: Reading the code of PetitParser, I wonder why PPRepeatingParser |
Re: [vwnc] Parsing in Smalltalk
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Hi, I tried it some more times and things are different now:
- image appeared to lock up (1st) - no network traffic at all (2nd) - image unresponsive, loading successful after 2 minutes (3rd) Call me a fool, but I didn't do anything different. Notably, it succeeded each time in 7.0. =) > There is no specific reason to use SmallInteger maxVal... and nobody > ever thought it might be too little. Maybe it makes sense to change this? It appears to be just wrong and on 32bit the limit is well in practical reach. With a little guidance, I'd try to do a first PR myself (if the change is considered sensible). I was mentioning #min: since it is implemented in terms of 'min: min max: SmallInteber maxVal'. Is there an easy way to create a character class, similar to [1-2x-z]? Best, Steffen > Use $- asPParser for characters, e.g: > $- asPParser parse: '-' > > [1]: https://travis-ci.org/kursjan/petitparser2/builds/438358467 > > On Thu, Oct 11, 2018 at 8:13 PM Steffen Märcker <[hidden email]> wrote: > >> Reading the code of PetitParser, I wonder why PPRepeatingParser >> initializes 'max' with SmallInteger maxVal instead of some notion of >> infinity, like Float infinity (and PP2RepeatingNode as well). If I >> understand the code correctly, PParser>>min: fails if the number of >> repetitions exceeds SmallInteger maxVal, doesn't it? >> >> Best, Steffen >> >> >> Am .10.2018, 17:10 Uhr, schrieb Steffen Märcker <[hidden email]>: >> >> > I am using MacOS 10.13.6 and the 32bit VM: >> > >> > Pharo 6.0 >> > Latest update: #60546 >> > >> > ... the String in about is wrong, it should be 6.1. I installed it via >> > the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I >> > just noticed, that the sources file is missing from vms/private/6521/, >> > too. >> > >> > Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris >> <[hidden email] >> >: >> > >> >> Steffen Märcker wrote >> >>> I did the following: >> >>> 1) Download and start Pharo 6.1 stable via the launcher. >> >>> 2b) Attempt to install PP2 via the scripts from GitHub: >> >>> Metacello new >> >>> baseline: 'PetitParser2'; >> >>> repository: 'github://kursjan/petitparser2'; >> >>> load. >> >>> Metacello new >> >>> baseline: 'PetitParser2Gui'; >> >>> repository: 'github://kursjan/petitparser2'; >> >>> load. >> >> >> >> This way worked for me in Pharo #60546 (check in >> World->System->About). >> >> What >> >> exact Pharo version/OS are you on? 32 or 64-bit >> >> >> >> >> >> >> >> ----- >> >> Cheers, >> >> Sean >> >> -- >> >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >> >> >> > >> > >> |
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In reply to this post by Ben Coman
HI Steffen, Thanks for the report, number pleases me :) Speaking of tool for porting, I was recently showed this one, I don't have any experience with it: Speaking of character ranges, there is currently available: #letter asPParser (to recognize character matching #isLetter predicate) #word asPParser (characters matching #isAlphaNumeric predicate) #digit (#isDigit predicate) #hex ([a-fA-F]) #space #blank #any You can find definitions in PP2NodeFactory, see implementation of #hex, which is probably closest to what you want. For your convenience, your project can extend the class to fit your needs. You can also specify:$a asPParser / $b asPParser / $c asPParser / #digit asPParser ... PetitParser2 can recognize this pattern and makes a character class during optimization pass. On Sat, Oct 13, 2018 at 5:38 PM Steffen Märcker <[hidden email]> wrote: Hi, |
Re: [vwnc] Parsing in Smalltalk
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In reply to this post by Jan Kurš
Hi Jan,
I am trying to port PP2 to VW and managed to get most of the tests green. =) Some of the remaining test failures occur in PP2DebuggingStrategy>>cacheIfNeeded:debugResult: where a result of nil is to be stored in an IdentityDictionary. But in VW Dictionaries do not accept nil as a key. If this is indeed intended, I wonder how to circumvent the limitation best. Would it be feasible to use a placeholder object instead of nil (which code would be effected)? Or would it be better to not cache nil at all? I'd be happy to hear your thoughts. Best, Steffen Am .10.2018, 20:58 Uhr, schrieb Jan Kurš <[hidden email]>: > I run PP2 on travis [1], seems Pharo 6.1 loads all configurations, both > on > linux and mac. Pharo 5, Pharo 6.0 got broken, why is build configuration > so > hard :'( I don't know, how can I support you. I myself had to gave up on > some tools, because I failed to load them. > > There is no specific reason to use SmallInteger maxVal... and nobody > ever > thought it might be too little. 'PP2 min: X' fails if there are less > repetitions that X. 'PP2 max: X' parses at most X repetitions. > > ($a asPParser min: 2 max: 3) parse: 'a'. -> Failure > ($a asPParser min: 2 max: 3) parse: 'aa'. #($a $a) > ($a asPParser min: 2 max: 3) parse: 'aaa'. #($a $a $a) > ($a asPParser min: 2 max: 3) parse: 'aaaa'. #($a $a $a) > > > Use $- asPParser for characters, e.g: > $- asPParser parse: '-' > > [1]: https://travis-ci.org/kursjan/petitparser2/builds/438358467 > > On Thu, Oct 11, 2018 at 8:13 PM Steffen Märcker <[hidden email]> wrote: > >> Reading the code of PetitParser, I wonder why PPRepeatingParser >> initializes 'max' with SmallInteger maxVal instead of some notion of >> infinity, like Float infinity (and PP2RepeatingNode as well). If I >> understand the code correctly, PParser>>min: fails if the number of >> repetitions exceeds SmallInteger maxVal, doesn't it? >> >> Best, Steffen >> >> >> Am .10.2018, 17:10 Uhr, schrieb Steffen Märcker <[hidden email]>: >> >> > I am using MacOS 10.13.6 and the 32bit VM: >> > >> > Pharo 6.0 >> > Latest update: #60546 >> > >> > ... the String in about is wrong, it should be 6.1. I installed it via >> > the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I >> > just noticed, that the sources file is missing from vms/private/6521/, >> > too. >> > >> > Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris >> <[hidden email] >> >: >> > >> >> Steffen Märcker wrote >> >>> I did the following: >> >>> 1) Download and start Pharo 6.1 stable via the launcher. >> >>> 2b) Attempt to install PP2 via the scripts from GitHub: >> >>> Metacello new >> >>> baseline: 'PetitParser2'; >> >>> repository: 'github://kursjan/petitparser2'; >> >>> load. >> >>> Metacello new >> >>> baseline: 'PetitParser2Gui'; >> >>> repository: 'github://kursjan/petitparser2'; >> >>> load. >> >> >> >> This way worked for me in Pharo #60546 (check in >> World->System->About). >> >> What >> >> exact Pharo version/OS are you on? 32 or 64-bit >> >> >> >> >> >> >> >> ----- >> >> Cheers, >> >> Sean >> >> -- >> >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >> >> >> > >> > >> |
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We will have the same issue porting PP2 to GemStone and look forward to suggestions.
> On Oct 22, 2018, at 4:40 AM, Steffen Märcker <[hidden email]> wrote: > > Hi Jan, > > I am trying to port PP2 to VW and managed to get most of the tests green. =) Some of the remaining test failures occur in > > PP2DebuggingStrategy>>cacheIfNeeded:debugResult: > > where a result of nil is to be stored in an IdentityDictionary. But in VW Dictionaries do not accept nil as a key. If this is indeed intended, I wonder how to circumvent the limitation best. Would it be feasible to use a placeholder object instead of nil (which code would be effected)? Or would it be better to not cache nil at all? > > I'd be happy to hear your thoughts. > > Best, Steffen > > > > > > Am .10.2018, 20:58 Uhr, schrieb Jan Kurš <[hidden email]>: > >> I run PP2 on travis [1], seems Pharo 6.1 loads all configurations, both on >> linux and mac. Pharo 5, Pharo 6.0 got broken, why is build configuration so >> hard :'( I don't know, how can I support you. I myself had to gave up on >> some tools, because I failed to load them. >> >> There is no specific reason to use SmallInteger maxVal... and nobody ever >> thought it might be too little. 'PP2 min: X' fails if there are less >> repetitions that X. 'PP2 max: X' parses at most X repetitions. >> >> ($a asPParser min: 2 max: 3) parse: 'a'. -> Failure >> ($a asPParser min: 2 max: 3) parse: 'aa'. #($a $a) >> ($a asPParser min: 2 max: 3) parse: 'aaa'. #($a $a $a) >> ($a asPParser min: 2 max: 3) parse: 'aaaa'. #($a $a $a) >> >> >> Use $- asPParser for characters, e.g: >> $- asPParser parse: '-' >> >> [1]: https://travis-ci.org/kursjan/petitparser2/builds/438358467 >> >> On Thu, Oct 11, 2018 at 8:13 PM Steffen Märcker <[hidden email]> wrote: >> >>> Reading the code of PetitParser, I wonder why PPRepeatingParser >>> initializes 'max' with SmallInteger maxVal instead of some notion of >>> infinity, like Float infinity (and PP2RepeatingNode as well). If I >>> understand the code correctly, PParser>>min: fails if the number of >>> repetitions exceeds SmallInteger maxVal, doesn't it? >>> >>> Best, Steffen >>> >>> >>> Am .10.2018, 17:10 Uhr, schrieb Steffen Märcker <[hidden email]>: >>> >>> > I am using MacOS 10.13.6 and the 32bit VM: >>> > >>> > Pharo 6.0 >>> > Latest update: #60546 >>> > >>> > ... the String in about is wrong, it should be 6.1. I installed it via >>> > the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" I >>> > just noticed, that the sources file is missing from vms/private/6521/, >>> > too. >>> > >>> > Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris <[hidden email] >>> >: >>> > >>> >> Steffen Märcker wrote >>> >>> I did the following: >>> >>> 1) Download and start Pharo 6.1 stable via the launcher. >>> >>> 2b) Attempt to install PP2 via the scripts from GitHub: >>> >>> Metacello new >>> >>> baseline: 'PetitParser2'; >>> >>> repository: 'github://kursjan/petitparser2'; >>> >>> load. >>> >>> Metacello new >>> >>> baseline: 'PetitParser2Gui'; >>> >>> repository: 'github://kursjan/petitparser2'; >>> >>> load. >>> >> >>> >> This way worked for me in Pharo #60546 (check in >>> World->System->About). >>> >> What >>> >> exact Pharo version/OS are you on? 32 or 64-bit >>> >> >>> >> >>> >> >>> >> ----- >>> >> Cheers, >>> >> Sean >>> >> -- >>> >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>> >> >>> > >>> > >>> > > |
Re: [vwnc] Parsing in Smalltalk
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Hi,
my current shot is to subclass IdentityDictionary with NildentityDictionary. The class checks on indexed access whether the key is nil. If so, storing/retrival uses a singleton Object as key (stored in instance variable NIL := Object new). I needed to override at least: >>at:ifAbsent: >>associationsAt:ifAbsent: >>at:put: >>findElementLike:ifAbsent: >>initialize class>>new class>>new: It works for PP2 (without serious performance impact so far), although the class is yet incomplete wrt. Collection/Dictionary protocol. Currently, all but the Morphic-related tests are green. \o/ After some cleanup of the bundles, I'll publish an inital version to the Public Store. @James: If you like, I we could discuss our ports later to double-check an making the future process easier. How about that? @Jan: I'd be happy to hear your thoughts on the porting matter. Best, Steffen Am .10.2018, 16:06 Uhr, schrieb James Foster <[hidden email]>: > We will have the same issue porting PP2 to GemStone and look forward to > suggestions. > >> On Oct 22, 2018, at 4:40 AM, Steffen Märcker <[hidden email]> wrote: >> >> Hi Jan, >> >> I am trying to port PP2 to VW and managed to get most of the tests >> green. =) Some of the remaining test failures occur in >> >> PP2DebuggingStrategy>>cacheIfNeeded:debugResult: >> >> where a result of nil is to be stored in an IdentityDictionary. But in >> VW Dictionaries do not accept nil as a key. If this is indeed intended, >> I wonder how to circumvent the limitation best. Would it be feasible to >> use a placeholder object instead of nil (which code would be effected)? >> Or would it be better to not cache nil at all? >> >> I'd be happy to hear your thoughts. >> >> Best, Steffen >> >> >> >> >> >> Am .10.2018, 20:58 Uhr, schrieb Jan Kurš <[hidden email]>: >> >>> I run PP2 on travis [1], seems Pharo 6.1 loads all configurations, >>> both on >>> linux and mac. Pharo 5, Pharo 6.0 got broken, why is build >>> configuration so >>> hard :'( I don't know, how can I support you. I myself had to gave up >>> on >>> some tools, because I failed to load them. >>> >>> There is no specific reason to use SmallInteger maxVal... and nobody >>> ever >>> thought it might be too little. 'PP2 min: X' fails if there are less >>> repetitions that X. 'PP2 max: X' parses at most X repetitions. >>> >>> ($a asPParser min: 2 max: 3) parse: 'a'. -> Failure >>> ($a asPParser min: 2 max: 3) parse: 'aa'. #($a $a) >>> ($a asPParser min: 2 max: 3) parse: 'aaa'. #($a $a $a) >>> ($a asPParser min: 2 max: 3) parse: 'aaaa'. #($a $a $a) >>> >>> >>> Use $- asPParser for characters, e.g: >>> $- asPParser parse: '-' >>> >>> [1]: https://travis-ci.org/kursjan/petitparser2/builds/438358467 >>> >>> On Thu, Oct 11, 2018 at 8:13 PM Steffen Märcker <[hidden email]> wrote: >>> >>>> Reading the code of PetitParser, I wonder why PPRepeatingParser >>>> initializes 'max' with SmallInteger maxVal instead of some notion of >>>> infinity, like Float infinity (and PP2RepeatingNode as well). If I >>>> understand the code correctly, PParser>>min: fails if the number of >>>> repetitions exceeds SmallInteger maxVal, doesn't it? >>>> >>>> Best, Steffen >>>> >>>> >>>> Am .10.2018, 17:10 Uhr, schrieb Steffen Märcker <[hidden email]>: >>>> >>>> > I am using MacOS 10.13.6 and the 32bit VM: >>>> > >>>> > Pharo 6.0 >>>> > Latest update: #60546 >>>> > >>>> > ... the String in about is wrong, it should be 6.1. I installed it >>>> via >>>> > the launcher as "Official Distribution: Pharo 6.1 - 32Bit (stable)" >>>> I >>>> > just noticed, that the sources file is missing from >>>> vms/private/6521/, >>>> > too. >>>> > >>>> > Am .10.2018, 17:02 Uhr, schrieb Sean P. DeNigris >>>> <[hidden email] >>>> >: >>>> > >>>> >> Steffen Märcker wrote >>>> >>> I did the following: >>>> >>> 1) Download and start Pharo 6.1 stable via the launcher. >>>> >>> 2b) Attempt to install PP2 via the scripts from GitHub: >>>> >>> Metacello new >>>> >>> baseline: 'PetitParser2'; >>>> >>> repository: 'github://kursjan/petitparser2'; >>>> >>> load. >>>> >>> Metacello new >>>> >>> baseline: 'PetitParser2Gui'; >>>> >>> repository: 'github://kursjan/petitparser2'; >>>> >>> load. >>>> >> >>>> >> This way worked for me in Pharo #60546 (check in >>>> World->System->About). >>>> >> What >>>> >> exact Pharo version/OS are you on? 32 or 64-bit >>>> >> >>>> >> >>>> >> >>>> >> ----- >>>> >> Cheers, >>>> >> Sean >>>> >> -- >>>> >> Sent from: >>>> http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>> >> >>>> > >>>> > >>>> >> >> > |
Re: [vwnc] Parsing in Smalltalk
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In reply to this post by Ben Coman
I rediscovered this thread while pondering an (existential?!) problem:
Why do we keep having to write, and rewrite, and rewrite, ad infinitum, parsers for well known domains like rfc specs? The parser world in many ways feels like a modern post-"Tower of Babel". I was really excited about the reverse parsing stuff done in Squeak by Ted Kaehler and Alessandro Warth [1], which never seemed to get picked up. Steffen Märcker wrote > I wrote a PetitParserGenerator that takes the DSL and builds a > PetitParser. I don't know how I could've missed this gem! I hope Steffen is still subscribed. I googled "PetitParserGenerator", but only found these ML posts :/ IIRC Xtreams can take a BNF and generate a parser. I was thinking about implementing a BNF parser in PetitParser, but would love to avoid that, wouldn't mind a two step BNF -> Xtreams -> PP process. Although there was this SO reply [2] where Lukas said that one can't necessarily blindly feed a BNF to a PEG. It also got me thinking about sharing parsers between PP and PP2, since in many cases it seems that only the internal class names would differ... [1] http://www.vpri.org/pdf/m2008001_parseback.pdf [2] https://stackoverflow.com/a/9443024/424245 ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Cheers,
Sean |
Re: [vwnc] Parsing in Smalltalk
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Dear Sean,
thanks for bringing this up and for the interesting link [1]. I'll have a look. Meanwhile, I am still on both lists. ;-) > Steffen Märcker wrote >> I wrote a PetitParserGenerator that takes the DSL and builds a >> PetitParser. > > I don't know how I could've missed this gem! I hope Steffen is still > subscribed. I googled "PetitParserGenerator", but only found these ML > posts > :/ It was easy to miss, since I never actually posted that code. Here's what I've done: From Xtreams.PEG syntax: - PetitParserGenerater > PetitParser code - PetitParserParser > PetitParser instance I can send you that code. It should be straight forward to adapt it for PP2. However, I moved away from Xtreams own PEG flavor to Bryan Ford's original PEG syntax (close but more common) and programmed for Xtreams, PP and PP2: From Bryan Ford's original PEG syntax: 1. Xtreams Grammer and Actor that build an Xtreams parser 2. PP(2)PEGParserParser that builds a PP(2) parser instance 3. PP(2)PEGParserCompiler that builds PP(2) parser classes All three are available for VW in the Cincom's public repository: - Xtreasm-Parsing (8.2-3,stm): +PEG parser +some fixes to Xtreams parser - PetitParser-PEG (1.11,stm) - PetitParser2-PEG (1.11,stm) And 2, 3 for Pharo on GitHub, e.g. - https://github.com/kursjan/petitparser2/tree/master/PetitParser2-PEG Speaking of, I just noticed that translator form Xtreams.PEG to PEG is missing to complete the picture here. ;-) > IIRC Xtreams can take a BNF and generate a parser. As far as I know, there is no BNF-like parser generator for Xtreams, available. > wouldn't mind a two step BNF -> Xtreams -> PP process. Is it an option for you to convert your BNF to PEG manually? Best regards, Steffen |
Re: [vwnc] Parsing in Smalltalk
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Administrator
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Steffen Märcker wrote
> I can send you that code. Awesome. I'll email you. Although, I wonder how relevant this is given your answers down below. Are there many grammars available in Xtreams syntax to make this useful? Also, what is the license? Can I add it somewhere on GH under MIT (with attribution of course)? Steffen Märcker wrote > However, I moved away from Xtreams own PEG flavor to Bryan Ford's > original PEG syntax (close but more common) Ah, interesting. I didn't realize that Xtreams used a custom PEG syntax. I wonder why?! Steffen Märcker wrote > From Bryan Ford's original PEG syntax: > 1. Xtreams Grammer and Actor that build an Xtreams parser > ... > All three are available for VW in the Cincom's public repository: > - Xtreasm-Parsing (8.2-3,stm): +PEG parser +some fixes to Xtreams parser I'd certainly like to port that at some point, but I'm currently fairly mystified about the best practice process. I just reached out to Pavel about the Ring2 approach on which he spoke at ESUG. Do you have a documented process or any pointers even? Steffen Märcker wrote > And 2, 3 for Pharo on GitHub, e.g. > - https://github.com/kursjan/petitparser2/tree/master/PetitParser2-PEG Great. I use PP2 a lot. So if IIUC, I can now feed a PEG-syntax grammar string and have a PP2 parser generated for it? Steffen Märcker wrote > Speaking of, I just noticed that translator form Xtreams.PEG to PEG is > missing to complete the picture here. ;-) Ah, yes that makes sense. Any idea how much effort would be involved? Steffen Märcker wrote > As far as I know, there is no BNF-like parser generator for Xtreams, > available. > ... > Is it an option for you to convert your BNF to PEG manually? I'm not a parsing expert, so that may have been what I'm already doing and I'm using the wrong terminology. I took the ABNF from rfc5322 [1] and adapted it slightly [2] to be consumed by Xtreams [3] [OT?] As a final aside, I've been wondering if there's any way to generate "hand-rolled" equivalent parsers from Xtreams, PP, etc. for use cases where none of the libraries are available. I have in mind Pharo's MailMessage. It doesn't seem like any full-featured parsing libraries will be integrated any time soon, so the lowest levels use painful, duplication-riddled hand-rolled parsers. It would be great to leverage all this great library tech to create and reason about those... [/OT] Thanks for the discussion! 1. https://tools.ietf.org/html/rfc5322 2. https://github.com/seandenigris/Xtreams-Pharo/blob/master/repository/Xtreams-Email.package/PEGParser.extension/class/grammarEmail.st 3. https://github.com/seandenigris/Xtreams-Pharo/blob/master/repository/Xtreams-Email.package/PEGParserEmailTest.class/instance/setUp.st ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html
Cheers,
Sean |
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