November 2014 - Pharo-users

Memoization Question

by Torsten Bergmann

Werner Kassens wrote: >Hi, >now this a nice idea, especially the memoizedUsing:cache idea. i would >really appreciate it, if that would be MIT licenced. >werner It already is, thanks to the permission of author John Cromartie who answered us today. Both methods are in a slice already: Details in https://pharo.fogbugz.com/f/cases/14458 Thx T.

Nov. 11, 2014

Re: [Pharo-users] Memoization Question

by Werner Kassens

Hi, now this a nice idea, especially the memoizedUsing:cache idea. i would really appreciate it, if that would be MIT licenced. werner

Nov. 11, 2014

Re: [Pharo-users] Is there a way to store workspace 'gists' in Pharo?

by Andy Burnett

Stef said: << I usually create a method and a class. because script do not compose well. >> á§ > > Thanks, that sounds interesting. And, just for clarity, do you mean that you create a single class e.g. MyGists and then create methods for each of your useful snippets? Or, is there a benefit in creating a class per gist? Cheers

Nov. 11, 2014

Re: [Pharo-users] Is there a way to store workspace 'gists' in Pharo?

by Pierce Ng

On Tue, Nov 11, 2014 at 04:37:03PM +0100, stepharo wrote: > I usually create a method and a class. > because script do not compose well. +1 although I don't practise this well. I use ScriptManager but when my images proliferate it becomes messy to manage the scripts across images. Pierce

Nov. 11, 2014

Re: [Pharo-users] Memoization Question

by Sven Van Caekenberghe

This is cool indeed. I find an unlimited cache a bit coarse, would not really work in practice. What about memoizedUsing: cache ^ [ :x | cache at: x ifAbsentPut: [ self value: x ] ] then you could pass in a tuned LRUCache instance, among others. Sven > On 11 Nov 2014, at 16:24, Torsten Bergmann <astares(a)gmx.de> wrote: > > Phil wrote: >> thanks for the pointer. >> Now, how do I use that? > > > First: create a method BlockClosure>>#memoized in your Pharo image (see https://gist.github.com/jcromartie/2705526) > > memoized > "returns memoized version of an unary function" > | cache | > cache := Dictionary new. > ^ [ :x | cache at: x ifAbsentPut: [ self value: x ] ]! > > > So the idea of #memoized is to return a new "outer" block who evaluates the original block only when the computation > of the inner block was not yet done/the result of the inner evaluation is not yet cached. > > > As you see from the comment it works for "unary functions" which would mean it works > for "one argument blocks". Simple example: > > |square memo | > square:= [:x | Transcript show: 'Processing'. x * x]. > memo := square memoized. > memo value: 2. > memo value: 3. > memo value: 2. > > The Transcript only shows "Processing" two times instead of three times, so only for the first two #value: calls > we have to calculate x * x. > > For the last evaluation on the memo block (with argument 2 again) the result is already known from the cache, > so the square block is not evaluated again. Instead the cached result could be returned which could be faster > than doing the computation again. > > x*x is only an example - this "memoization" can usually speed up when a block is costly (performancewise) and > is often called with the same arguments. A precondition (for this caching) is that the block evalutes the > same way/returns the same result for the same input argument. > > > You also try the two prepared workspaces in Pharo: > > Non-memoized version: http://ws.stfx.eu/5ZE87XSFL9IH > Memoized Version: http://ws.stfx.eu/QLQLSLT7PZ4C > > Hope this makes it more clear. This simple example is a nice performance trick and shows again the power > of Smalltalk and block closures. > > Dont know about the license - but we could ask author John Cromartie for MIT license to include this simple > method into the standard image. I will try to contact him. > > Bye > T. >

Nov. 11, 2014

Re: [Pharo-users] Is there a way to store workspace 'gists' in Pharo?

by stepharo

Hi andy I usually create a method and a class. because script do not compose well. Stef > From time to time I write a workspace script that I would like to > keep. Obviously, I could save them to a file, but I was wondering if > there was a way of saving them in the image, and browsing them in some > friendly way? > > Cheers > Andy > á§

Nov. 11, 2014

Re: [Pharo-users] Memoization Question

by Torsten Bergmann

Phil wrote: >thanks for the pointer. >Now, how do I use that? First: create a method BlockClosure>>#memoized in your Pharo image (see https://gist.github.com/jcromartie/2705526) memoized "returns memoized version of an unary function" | cache | cache := Dictionary new. ^ [ :x | cache at: x ifAbsentPut: [ self value: x ] ]! So the idea of #memoized is to return a new "outer" block who evaluates the original block only when the computation of the inner block was not yet done/the result of the inner evaluation is not yet cached. As you see from the comment it works for "unary functions" which would mean it works for "one argument blocks". Simple example: |square memo | square:= [:x | Transcript show: 'Processing'. x * x]. memo := square memoized. memo value: 2. memo value: 3. memo value: 2. The Transcript only shows "Processing" two times instead of three times, so only for the first two #value: calls we have to calculate x * x. For the last evaluation on the memo block (with argument 2 again) the result is already known from the cache, so the square block is not evaluated again. Instead the cached result could be returned which could be faster than doing the computation again. x*x is only an example - this "memoization" can usually speed up when a block is costly (performancewise) and is often called with the same arguments. A precondition (for this caching) is that the block evalutes the same way/returns the same result for the same input argument. You also try the two prepared workspaces in Pharo: Non-memoized version: http://ws.stfx.eu/5ZE87XSFL9IH Memoized Version: http://ws.stfx.eu/QLQLSLT7PZ4C Hope this makes it more clear. This simple example is a nice performance trick and shows again the power of Smalltalk and block closures. Dont know about the license - but we could ask author John Cromartie for MIT license to include this simple method into the standard image. I will try to contact him. Bye T.

Nov. 11, 2014

Memoization Question

by Torsten Bergmann

Nov. 10, 2014

Re: [Pharo-users] Ploting all history of the commits in a Monticello repository

by Stephan Eggermont

You might get some inspiration by taking a look at http://smalltalkhub.com/#!/~StephanEggermont/DeprecationFinder Stephan

Nov. 10, 2014

Ploting all history of the commits in a Monticello repository

by Offray Vladimir Luna CÃ¡rdenas

Hi, I don't know if the terminology is the proper one. Anyway I'm trying to plot a "time line" of the history of a project which is stored on [1] and [2] (after rebranding) and also of the commits to documentation on [3] using Pharo/Roassal. [1] http://smalltalkhub.com/#!/~Offray/Ubakye/ [2] http://smalltalkhub.com/#!/~Offray/Grafoscopio/ [3] http://mutabit.com/deltas/repos.fossil/grafoscopio/timeline?n=200 Given I don't know any API of the sites, I thought it would be easier by scraping the data on the web pages and the using it into Roassal, but after testing some solutions on python, I came back to pharo to see if I can made everything on it, including the data collection. For [1] and [2] I think that is possible to send a message to Monticello to show all commits of a specific package (like it actually does from the UI) and export them with the information about date of commit for all commits. For [3] I'm thinking in using some combination of Zinc with Soup[4] despite of the lack of tutorials. [4] http://www.squeaksource.com/@Y-xGMSBYZmiWQToh/GJDsBRqL So here are my questions: - There is any way to say to Monticello to export all commits dates and times for a specific package? - There is any advised scraping strategy for getting the same information from the web page at [3]? The plot I would like to do is similar to the one of the ebola example at [5], but using high as number of commits and x axis as dates. [5] https://dl.dropboxusercontent.com/u/31543901/AgileVisualization/QuickStart/… Any help is welcomed, as always. Cheers, Offray

Nov. 10, 2014