yeap noway I compare Regex with PettitParser. I will probably give a PettitParser a try, because I try to parse Pharo syntax to Python, I want now to parse Pharo classes to python class and that will be a nightmare with regex, so time to give PettitParser a serious try.
On Tue, Sep 23, 2014 at 1:10 PM, Udo Schneider <udo.schnei...@homeaddress.de > wrote: > > I have not used PettitParser yet, looks powerful but I find it a bit > > weird in design. On the other hand regex is quite ugly and understanding > > complex regex a pain. > I normally encounter two issues with RegExps: > > 1) The syntax between different apps/libs/frameworks differs sligtly. Esp. > for character classes or greediness. This drove me crazy more than one time. > 2) Often enough I realize (while developing the RegExp) that I need > something more capable than a Chomsky Type 3 parser (which RegExps are in a > way). So I have to use "a bigger gun" - e.g. PetitParser. > > CU, > > Udo > > > On 23.09.14 10:15, kilon alios wrote: > >> it reminds a lot of Kent's Beck Smalltalk Practice Patterns where it >> removes all ifs and replaces them with regular unary messages . It is >> definitely an elegant way of coding making the code just flow. >> >> I have not used PettitParser yet, looks powerful but I find it a bit >> weird in design. On the other hand regex is quite ugly and understanding >> complex regex a pain. >> >> On Tue, Sep 23, 2014 at 11:07 AM, Udo Schneider >> <udo.schnei...@homeaddress.de >> <mailto:udo.schnei...@homeaddress.de>> wrote: >> >> > just as it is black magic for me now :D >> The nice thing about this approach is the fact that it "just" >> piggybacks the normal Smalltalk message sending. So you can step >> through it using the Debugger - it's Smalltalk all the way down. >> >> I still remember my first shock when (having no formal background on >> parsing theory at that time) I saw the parsing tables generated by >> T-Gen. Of course it was Smalltalk ... but understanding those tables >> was a nightmare. >> >> PetitParser is the gold standard here IMHO. It is able to parse >> arbitrary input (compared to my block expressions only). And you can >> still use the Debugger to step through the parsing process *and >> still understand what's going on!* >> >> CU, >> >> Udo >> >> On 23.09.14 09:54, kilon alios wrote: >> >> just as it is black magic for me now :D >> >> At least I get the general feeling. I am new to parsing too, so >> far I >> have only played with regex parsing. Not the most smalltalkish >> way but >> it works well so far. >> >> On Tue, Sep 23, 2014 at 9:39 AM, Udo Schneider >> <udo.schnei...@homeaddress.de >> <mailto:udo.schnei...@homeaddress.de> >> <mailto:udo.schneider@__homeaddress.de >> >> <mailto:udo.schnei...@homeaddress.de>>> >> wrote: >> >> Hi Estaban, >> >> I think the first time I saw this pattern was in ReStore on >> Dolphin >> Smalltalk. I didn't understand it's implementation back >> then. I >> assume that it's similar to what I described though. But >> having a >> Smalltalk block automagically creating the equivalent SQL >> SELECT >> expression was like black magic at that time :-) >> >> CU, >> >> Udo >> >> >> >> >> On 23.09.14 04:15, Esteban A. Maringolo wrote: >> >> Excellent article. >> >> I think GLORP uses a similar technique to setup its >> expressions, and >> also have issues with #and:/#or: selectors due to >> inlining, so >> it uses >> AND:/#OR: instead. >> >> Regards! >> >> Esteban A. Maringolo >> >> pd: Your blog and it's choosen topic made me remember >> http://use-the-index-luke.com/ >> >> 2014-09-22 20:48 GMT-03:00 Udo Schneider >> <udo.schnei...@homeaddress.de >> <mailto:udo.schnei...@homeaddress.de> >> <mailto:udo.schneider@__homeaddress.de >> <mailto:udo.schnei...@homeaddress.de>>>__: >> >> >> All, >> >> I just finished a blog entry. It shows how to use >> Smalltalk >> blocks as parsers/translators. E.g. translating a >> Block >> >> [:customer | (customer joinDate year is: >> Date >> today year)] >> >> into an SQL-like String >> >> (YEAR(customers.joinDate) = 2014) >> >> The SQL stuff is just an example - you can create >> nearly any >> output. >> >> Check out >> http://readthesourceluke.__blo__gspot.de/2014/09/block-____ >> translators-parsing-magic.html >> <http://blogspot.de/2014/09/block-__translators-parsing- >> magic.html> >> >> <http://readthesourceluke.__blogspot.de/2014/09/block-__ >> translators-parsing-magic.html >> <http://readthesourceluke.blogspot.de/2014/09/block- >> translators-parsing-magic.html>__> >> >> Maybe that's old stuff for some of you - but I hope >> it's >> interesting for some at least :-) >> >> Comments and feedback appreciated. >> >> CU, >> >> Udo >> >> >> >> >> >> >> >> >> >> >> >> >> > > >
