June 2015 - Pharo-users - lists.pharo.org

Pratt Parsers for PetitParser
by Camille June 10, 2015

June 10, 2015

Hello Pharoers and Moosers, I did a Pratt parser extension for PetitParser. A Pratt parser (a.k.a top-down operator precedence parser) handles left-recursion and operator precedence. It handles grouping, prefix, postfix, infix (right- or left-associative) and "multifixâ operators (e.g. "if ... then ... else ...", "... ? ... : ...", Smalltalk keyword messages). Normally Pratt Parsing needs a tokenization phase but here tokenization is done on the fly with other PP parsers. Apart from tokenization, no backtracking is needed so parsing is quite fast (approximatively 2 times faster than PPExpressionParser). Here is an exemple of a calculator: parser := PPPrattParser new. "Numbers" parser terminal: #digit asParser plus do: [ :token | token inputValue asNumber ]. parser skip: #space asParser plus. "Parentheses" parser groupLeft: $( asParser right: $) asParser. "Addition, substraction, multiplication, division: all left infix, * and / have higher precedence than + and -" parser leftInfix: $+ asParser precedence: 1 do: [ :left :op :right | left + right ]. parser leftInfix: $- asParser precedence: 1 do: [ :left :op :right | left - right ]. parser leftInfix: $* asParser precedence: 2 do: [ :left :op :right | left * right ]. parser leftInfix: $/ asParser precedence: 2 do: [ :left :op :right | left / right ]. "Power: right infix with higher precedence than multiplication and division" parser rightInfix: $^ asParser precedence: 3 do: [ :left :op :right | left raisedTo: right ]. "Unary minus: prefix with highest precedence" parser prefix: $- asParser precedence: 4 do: [ :op :right | right negated ]. parser parse: '2*3 + 4^(1/2)*3' ----> 12 To try it: Gofer it smalltalkhubUser: 'CamilleTeruel' project: 'PetitPratt'; package: 'PetitPratt'; load Note that it is in beta stage so it might still change drastically. @PP Devs: I had trouble with the PPContext furthestFailure that is taken into account instead of the failures I return, so I had to redefine #parseWithContext: to return the failures I want. The results given by furthestFailure were not very meaningful in my case (the same is true for PPExpressionParser btw). But I guess it was introduced because it gives good results in other cases. So would it be possible to change this behavior to let the parser decide if it returns the furthestFailure or the original failure? Cheers, Camille

1 0

Using PluggableTextFieldMorph
by Jigyasa Grover June 10, 2015

June 10, 2015

Hi With reference to my earlier query 'Getting a user input string using Morphs' <http://forum.world.st/Getting-a-user-input-string-using-Morphs-td4831121.ht…> I have come across 'PluggableTextFieldMorph' which seems to be the one I was looking for. Could anyone pls help so as to how could I use the 'getText' method to retrieve the user input string. Thanks Jigyasa -- View this message in context: http://forum.world.st/Using-PluggableTextFieldMorph-tp4831375.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

4 3

Fuel and graph update
by Hilaire June 10, 2015

June 10, 2015

Hi, I want to use Fuel to persist a graph in file. The classic use case is "modify some part of the model and persist immediately". Now, it is not really efficient to re-serialize the whole graph each time, and I am wondering how you are approaching this particular point when using Fuel as your persistence back-end. For example, various ideas coming to my mind: - Is it possible to update some part of an already serialized graph? - Should the graph be cut to pieces and serialized in several files? - Or is Fuel fast enough to just re-serialize the whole graph? How about you? Thanks Hilaire -- Dr. Geo http://drgeo.eu http://google.com/+DrgeoEu

2 2

NativeBoost pointer and "+"
by Matthieu Lacaton June 9, 2015

June 9, 2015

Hello everyone, I have a small question about NativeBoost : How does the "+" operator when applied to a pointer translates into NativeBoost code ? To give a bit of context, what I want to do is to reallocate some non-contiguous bytes in memory to a buffer. Basically, I have an array of integers in a buffer and I want to copy some chunks of it in another buffer. The chunks are always the same size and the offset between each chunk is always the same too. Because a bit of actual code is easier to understand here is what I'd like to do in Pharo : ... int i, j; int *data = malloc(1000*sizeof(int)); int *newData = malloc(50*sizeof(int)); // Allocate initial data for (i = 0 ; i < 1000, i++) { data[i] = i; } //Copy desired chunks into new buffer for (i = 0; i < 5; i++ ) { memcpy( newData + j*10, data + 200 + j*30, 10*sizeof(int)); j++; } free(data); ... Here basically I'll get in my buffer chunks of 10 integers starting at 200 with an offset of 30 between chunks, and this 5 times. (200 201 202 ... 208 209 230 231 ... 238 239 260 ... 328 329). I am okay with the malloc, memcpy and free but I don't know how to handle the "+" operator in my memcpy function. Thank you, Matthieu

4 8

Pharo on bitnami
by stepharo June 9, 2015

June 9, 2015

Hi pharoers we got in contact with bitnami and I would love to see two bitnami apps around Pharo: - basic pharo - pharo + seaside + magritte + voyage (mongo pharo layer) + mongodb So who would like to help pushing this effort? Stef Begin forwarded message: From: Kevin Franklin <kevin(a)bitnami.com> Subject: Introducing Bitnami... Date: 5 Jun 2015 10:57:36 GMT+2 To: <board(a)pharo.org> Hello Pharo Association I wondered if you knew about Bitnami. Please check us out at www.bitnami.com. We provide over 120 apps and development stacks â many of them open-source. If you would like Pharo to be included in our marketplace, we have a contest https://bitnami.com/contest were you can nominate it, and encourage your community to vote for its inclusion. Also, I wondered if you could put me in touch with any commercial companies within and around the Pharo ecosystem that might like to work with us as a software partner https://bitnami.com/partners/software Kind regards Kevin -- Kevin Franklin Director of Business Development, Bitnami +44 78 2525 6020 @kevinjfranklin Run your favorite apps in the cloud with Bitnami Confidential - All Rights Reserved. Bitnami Â© 2015

8 8

Pharo sprint & Moose dojo this Friday
by Jean-Christophe Bach June 9, 2015

June 9, 2015

Hello Pharoers, We propose a Pharo sprint / Moose dojo this Friday, 12th June, starting at 10:00am. (Local Time Lille). It will be at the Inria Lille, Building B, third floor (RMoD offices). Remotely, you can join us on the official IRC channel #pharo on irc.freenode.net server. During the sprint, we will try to synchronize local and remote Pharo sprinters. As the building is not open to the public, please contact us before if you plan to come. JC

1 0

Using Spotter
by Alexandre Bergel June 8, 2015

June 8, 2015

Hi! If in spotter: 1- enter: Roassal2 #p 2- select: Roassal2 and press cmd -> 3- enter: Zoom Then I see all the classes that belongs to Roassal that have the word Zoom in them. The question I have is: how can I look for all the classes having Zoom in their name and begins with the prefix âRTâ? I have tried âRT*Zoom*â. I remember Juraj showed me a way to do this, but I forgotâ¦ Cheers, Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

4 4

VoyageMongo/Magritte problem
by mtk June 8, 2015

June 8, 2015

Hi, maybe I found an issue in VoyageMongo/Magritte, here is what I've done: loaded a fresh Pharo 4.0 image loaded VoyageMongo via Configuration Browser (Install Stable Version) opened up a Playground and did (via the green 'play' button): |repository| repository := VOMongoRepository host:'hostOn.mongolab.com' port: 43158 database:'databasename' username: 'username' password: 'password'. repository enableSingleton. repository inspect. This leads to an error which seems to be connected to 'gtInspectorMagritteIn:' (see attached screenshot) which was updated in the package Magritte-GT on 03.06.2015. (no instance 'repository' is going to be created). Please excuse my bad analysis on this, because I have only very limited skills. <http://forum.world.st/file/n4830859/VoyageMongo.png> -- View this message in context: http://forum.world.st/VoyageMongo-Magritte-problem-tp4830859.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

4 4

Issue with UDP Sockets
by Manfred KrÃ¶hnert June 7, 2015

June 7, 2015

Hello everyone, I am currently trying to get a list of UPnP device via SSDP (Simple Service Discovery Protocol). A minimalistic working NodeJS example looks like this: var dgram = require('dgram'); var message = new Buffer( "M-SEARCH * HTTP/1.1\r\n" + "HOST:239.255.255.250:1900\r\n" + "MAN:\"ssdp:discover\"\r\n" + "ST:ssdp:all\r\n" + "MX:1\r\n" + "\r\n" ); var client = dgram.createSocket("udp4"); client.on("message", function (msg, rinfo) { console.log("server got: " + msg + " from " + rinfo.address + ":" + rinfo.port); }); client.send(message, 0, message.length, 1900, "239.255.255.250"); client.close(); I tried to recreate the same functionality in Pharo with the following piece of code: | message udpSocket host | message := 'M-SEARCH * HTTP/1.1\r\n' , 'HOST:239.255.255.250:1900\r\n' , 'MAN:"ssdp:discover"\r\n' , 'ST:ssdp:all\r\n' , 'MX:1\r\n' , '\r\n'. udpSocket := Socket newUDP. host := (NetNameResolver addressFromString: '239.255.255.250'). udpSocket sendData: message toHost: host port: 1900. "udpSocket waitForData." Transcript show: 'Received: ' , udpSocket receiveData. udpSocket closeAndDestroy. Unfortunately, this script hangs both in Pharo3 and Pharo4 (OS X 10.10, Pharo 30856 and 40611). When I interrupt with Cmd+. the debugger shows the method Socket>>waitForDataIfClosed: and the hang is apparently in the line self readSemaphore wait Could anyone give me some advice if I should to do this differently or what the issue with the Pharo script is? Thanks in advance, Manfred

9 31

looking for Pharo by example in Korean
by stepharo June 7, 2015

June 7, 2015

Hi guys I know that there was a translation of Pharo by Example in Korean and I would like to put in on the Pharo Started Kit :) Yes we will announce it soon :) Stef

2 1