- Pharo-users - lists.pharo.org

Re: [Pharo-users] Find after in strings?

by Richard O'Keefe

I forgot to mention that in order to be able to translate XPath to Smalltalk I added these methods to my Smalltalk: AbstractSequence>> afterSubCollection: aSequence [ifAbsent: exceptionBlock] "based on substring-after" beforeSubCollection: aSequence [ifAbsent: exceptionBlock] "based on substring-before" I'm not going to display the code, which is pretty simple, because there is a serious efficiency problem with these. (The Java equivalent, had there been one, would not have had this problem, but since I think Java 7 it would too.) Imagine that we have a string consisting of N instances of separators, and we want to split it into pieces. [s includesSubCollection: separator] whileTrue: [ self process: (s beforeSubCollection: separator). s := s afterSubCollection: separator]. s isEmpty ifFalse: [ self process: s]. Do I need to explain why this takes O(N**2) time? However, r := ReadStream on: s. [r atEnd] whileFalse: [ self process: (r upToAll: separator)]. is linear time (assuming an efficient #upToAll:). My previous remarks about boundary issues apply here as well, of course. My previous remarks about wanting to see the context do too. On Sun, 2 Jun 2019 at 00:43, Ben Coman <btc(a)openinworld.com> wrote: > On Sat, 1 Jun 2019 at 18:01, Tim Mackinnon <tim(a)testit.works> wrote: > > > > Maybe this is a dumb question - and often Iâm surprised when asking > these, but why is there no way to âfind afterâ a string. > > > > I find it rather boring to try and parse a string, after a known marker > - thus: > > (loc := aString findString: âmarkerâ) > 0 ifTrue: [ loc := loc + > âmarkerâ size ]. > > > > Is there a better way? This whole pattern seems very old and clunky and > not smalltalk like? > > > > Couldnât we have: findAfter: aString ifAbsent: aBlock ? > > > > Or is there a whole better pattern for string searching that Iâm missing > ? > > Can your input be split into tokens using Stirng>>findTokens: > and `ReadStream on: that`. Then you marker will be consumed by a single > #next. > > cheers -ben > >

June 1, 2019

Re: [Pharo-users] Find after in strings?

by Ben Coman

On Sat, 1 Jun 2019 at 18:01, Tim Mackinnon <tim(a)testit.works> wrote: > > Maybe this is a dumb question - and often Iâm surprised when asking these, but why is there no way to âfind afterâ a string. > > I find it rather boring to try and parse a string, after a known marker - thus: > (loc := aString findString: âmarkerâ) > 0 ifTrue: [ loc := loc + âmarkerâ size ]. > > Is there a better way? This whole pattern seems very old and clunky and not smalltalk like? > > Couldnât we have: findAfter: aString ifAbsent: aBlock ? > > Or is there a whole better pattern for string searching that Iâm missing ? Can your input be split into tokens using Stirng>>findTokens: and `ReadStream on: that`. Then you marker will be consumed by a single #next. cheers -ben

June 1, 2019

Re: [Pharo-users] Find after in strings?

by Richard O'Keefe

If you want to move around in strings, you might want to use a ReadStream. In some Smalltalk systems there is a method called #skipToAll:. Here's how mine starts out: skipToAll: aSequence "If the remaining elements can be parsed as <a><aSequence><b>, return true leaving the position where? Otherwise return false. GNU Smalltalk, Dolphin, and VisualAge: leave the position after <aSequence>, consistent with #upToAll:, and implementable in this class. (GST uses the KMP algorithm.) VisualWorks and ST/X: leave the position before <aSequence>, inconsistent with #upToAll:, and only implementable for positionable streams. Squeak 5.2 and Pharo 6.0: not provided. I cannot be compatible with everything. The semantics of #skipToAll: should obviously match #upToAll:, so I'll fit in with GNU, Dolphin, and VisualAge Smalltalk. " So (myReadStream skipToAll: 'marker') ifTrue: [loc := myReadStream position] ifFalse: [alternative code]. HOWEVER, I have a bad feeling about this. The entire approach, as with much concerning strings in a Unicode age, seems fraught with peril. Consider input = 'the need for vigilance is never-ending' marker = 'end' Should the marker be found or not? input = '.... Si<floating acute accent> ...' marker = 'Si' Should the marker be found or not? My code is NOT sensitive to these issues. I would like to say that it was because I was writing a compatibility method, so my code was compatibly broken, but to be honest, I was stupid and forgot to think it through. I would think that there would need to be an '... asTokens: aBoolean' variant that checks that a match - is not followed by floating diacriticals - is not preceded by an alphanumeric if the target begins with one - is not followed by an alphanumeric if the target ends with one. My own preference is to write a lexical analyser for the mini-language I'm using, and NOT try to hack at it using general-purpose string methods. Perhaps you can tell us more about the context? What is the application- level task you are trying to solve? On Sat, 1 Jun 2019 at 22:01, Tim Mackinnon <tim(a)testit.works> wrote: > Maybe this is a dumb question - and often Iâm surprised when asking these, > but why is there no way to âfind afterâ a string. > > I find it rather boring to try and parse a string, after a known marker - > thus: > (loc := aString findString: âmarkerâ) > 0 ifTrue: [ loc := loc + âmarkerâ > size ]. > > Is there a better way? This whole pattern seems very old and clunky and > not smalltalk like? > > Couldnât we have: findAfter: aString ifAbsent: aBlock ? > > Or is there a whole better pattern for string searching that Iâm missing ? > > Tim >

June 1, 2019

Find after in strings?

by Tim Mackinnon

Maybe this is a dumb question - and often Iâm surprised when asking these, but why is there no way to âfind afterâ a string. I find it rather boring to try and parse a string, after a known marker - thus: (loc := aString findString: âmarkerâ) > 0 ifTrue: [ loc := loc + âmarkerâ size ]. Is there a better way? This whole pattern seems very old and clunky and not smalltalk like? Couldnât we have: findAfter: aString ifAbsent: aBlock ? Or is there a whole better pattern for string searching that Iâm missing ? Tim

May 31, 2019

Finder blows me away again

by Ben Coman

Just sharing... I wondered if there was a better way of converting an array of strings into one string than doing this... x := #( '++' '||' '++') . x flatCollect: [ :c | c ] but it was awkward copying the array twice into Finder. So I wondered if it could do variable assignment, and it can!! i.e... Tools > Finder > Examples > then simply paste the above snippet into the textfield. cheers -ben

May 31, 2019

Re: [Pharo-users] [gemstones] Use case for GsDevKit_home

by Dale Henrichs

On 5/30/19 11:12 AM, sergio ruiz wrote: > Whewâ¦ hefty.. digging into this now.. Haha ... this is why backup and restore functionality has been built into tODE:) and GsDevKit_home ... Dale

May 30, 2019

Re: [Pharo-users] [gemstones] Use case for GsDevKit_home

by Dale Henrichs

On 5/30/19 6:58 AM, James Foster wrote: > >> On May 30, 2019, at 5:44 AM, sergio ruiz <sergio.rrd(a)gmail.com >> <mailto:sergio.rrd@gmail.com>> wrote: >> >> ... >> >> Also, one thing that I find invaluable in troubleshooting >> applications written using relational databases is to be able to be >> able to just dump the production database and load it up on my local >> machine. Is this possible using gemstones? > > Backup and restore? This would be a valid alternative to doing `bu snapshot` (a form of backup) and newExtent ... In GsDevKit_home, use $GS_HOME/bin/todeBackup and $GS_HOME/bin/todeRestore to do a backup and restore ... these are bash scripts that call the tODE commands `bu backup` and `bu restore`, you will see docs for these commands when do the `man bu` ... if you are doing regular production backups (which you should be) you could simply restore from backup into your sandbox stone, whenever you want to start with a fresh extent ... While we are at it, take a look at the bash script $GS_HOME/bin/todeIt that allows you to call tode commands from bash ... a convenient way for you to do your deployment scripts, where you can write your own tODE command line scripts and then call them from bash ... With GemStone 3.5.0 (not yet released), it will be practical to write topaz/smalltalk/stash[1] bash command line scripts for deployment ... I plan to give a talk on stash[1] at ESUG this year:) Dale [1] https://github.com/dalehenrich/stash

May 30, 2019

Re: [Pharo-users] [gemstones] Use case for GsDevKit_home

by Dale Henrichs

On 5/30/19 5:44 AM, sergio ruiz wrote: > > I have another project coming up, and I have free reign over the tech > stack. I am gonna use Pharo, but I'd like to spend my up front time on > this project figuring out the things I usually wait until the end to > do. One of these issues is setting up gemstones. > > I would like to use GsDevKit_home, but I want to make sure that the > use case I am envisioning is in keeping what this package is set up to do. > > My vision is something like: > - Deploy a stone to remote production server. > - Develop in the latest version of Pharo on my local machine, keeping > my project in git. > - When it's time to deploy, Â use tODE client to tell the production > server to grab the latest code, and we're done. This sounds okay ... I'd be inclined to have you also include a sandbox or QA stone in your setup, that is either a copy of the production db, or a db filled with test data, that you would use to validate your update process/code before each release to production ... better safe debugging in a sandbox, than sorry debugging in a production db:) > > Does this sound reasonable? > > Also, one thing that I find invaluable in troubleshooting applications > written using relational databases is to be able to be able to just > dump the production database and load it up on my local machine. Is > this possible using gemstones? Good you are thinking along the same lines ... You can take a snapshot of an extent in a running stone using the tODE command `bu snapshot` (run `man bu` in a tODE shell ) for more details, then using the GsDevKit_home bash script, $GS_HOME/bin/newExtent ( `$GS_HOME/bin/newExtent -h` for more details) you can install the snapshot from production into a local sandbox stone ... For future questions about GsDevKit_home and GemSTone, please the GLASS mailing list[1][2]. There are a number of folks in the wild that are using the develop in Pharo, deploy in GemStone model so you'll benefit from having those folks weigh in with their approaches as well, without cluttering the Pharo newsgroup with GemStone information. Also there are few more GemTalk employees that monitor the GLASS list and can weigh in with their knowledge as well :) Dale [1] http://forum.world.st/GLASS-f1460844.html [2] https://lists.gemtalksystems.com/mailman/listinfo/glass > > Thanks! > > > > ---- > peace, > sergio > photographer, journalist, visionary > > Public Key: http://bit.ly/29z9fG0 > #BitMessageÂ BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV > http://www.codeandmusic.com > http://www.twitter.com/sergio_101 > http://www.facebook.com/sergio101

May 30, 2019

Re: [Pharo-users] [gemstones] Use case for GsDevKit_home

by sergio ruiz

Whewâ¦ hefty.. digging into this now.. Thanks! On May 30, 2019 at 2:10:56 PM, James Foster (smalltalk(a)jgfoster.net) wrote: Yes, GemStone supports backup and restore. See 11. Making and Restoring Backups <https://downloads.gemtalksystems.com/docs/GemStone64/3.4.x/GS64-SysAdminGui…> . ---- peace, sergio photographer, journalist, visionary Public Key: http://bit.ly/29z9fG0 #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.codeandmusic.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101

May 30, 2019

Re: [Pharo-users] [gemstones] Use case for GsDevKit_home

by James Foster

Yes, GemStone supports backup and restore. See 11. Making and Restoring Backups <https://downloads.gemtalksystems.com/docs/GemStone64/3.4.x/GS64-SysAdminGui…>. > On May 30, 2019, at 8:47 AM, sergio ruiz <sergio.rrd(a)gmail.com> wrote: > > > Yes! Does Gemstones have this ability? > > On May 30, 2019 at 9:59:31 AM, James Foster (smalltalk(a)jgfoster.net <mailto:smalltalk@jgfoster.net>) wrote: > >> Backup and restore? >> >> James > ---- > peace, > sergio > photographer, journalist, visionary > > Public Key: http://bit.ly/29z9fG0 <http://bit.ly/29z9fG0> > #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV > http://www.codeandmusic.com <http://www.codeandmusic.com/> > http://www.twitter.com/sergio_101 <http://www.twitter.com/sergio_101> > http://www.facebook.com/sergio101 <http://www.facebook.com/sergio101>

May 30, 2019