At 1:26 PM -0500 1/21/98, Mark Guzdial wrote:

I've been saving up a list of general Squeak questions, and when adding one today, I decided to ask them all at once:

• What's the easiest way of moving a method from one protocol to another,

or a class from one category to another? For the former, I've been cutting-pasting code, but I can't figure out how to do the latter.

The easiest way (I think) to move methods from protocal to protocal is the "reorganize" menu command associated with the protocal list in the browsers. Just copy and paste the method names into the desired protocal array.

From the class #Magnitude

('comparing' < <= = > >= between:and: hash hashMappedBy:) ('testing' max: min: min:max:)

To move hash from comparing to testing, accept

('comparing' < <= = > >= between:and: hashMappedBy:) ('testing' max: min: min:max: hash)

As for changing the category of a class, all you need to do is edit the definition. For example, to move (for no good reason) the class #magnitude from the category "Numeric-Magnitudes" to "Numeric-Numbers" select the class (or the class list menu item 'definition'):

Object subclass: #Magnitude instanceVariableNames: '' classVariableNames: '' poolDictionaries: '' category: 'Numeric-Magnitudes'

Then edit the category and accept the change:

Object subclass: #Magnitude instanceVariableNames: '' classVariableNames: '' poolDictionaries: '' category: 'Numeric-Numbers'

It's just like adding a variable!

Cheers, Bijan Parsia

(Mark, I'm ccing a copy to you since my posts to the list don't seem to be showing up. If you get two copies could you let me know?)

• What's the easiest way of moving a method from one protocol to another,

or a class from one category to another? For the former, I've been cutting-pasting code, but I can't figure out how to do the latter.

Moving a method: * choose "reorganize" from the category list menu, or * copy the method, change to the new category, paste and accept the method

Moving a class: * enter the new class category in the class definition and accept

• I have some ordered collections that contain BlockContexts (e.g., the

backup jobs list in PWS). When I inspect the collection, I just see "Undefined DoIt". If I inspect deeper, I can get to the bytecodes, but that's just a bit too far for me. Is there anyway to see what the original BlockContext looked like?

The BlockContexts should actually look like "[] in PWS class>>initialize" and not like "[] in FakeClassPool>>doIt" unless you've added the backup job manually. Printing these contexts nicely would probably involve modifying the Decompiler.

• I'm confused about ChangeSets vs. Projects vs. Change files. Ted K.

recently suggested that I look at the Change Sorter, which is a majorly cool gadget. But I suddenly discovered that, in my 1.23 image, I had the new things from 1.21 and 1.22 in different change sets. But I had no projects with those names, and I thought that ChangeSets and Projects were related. And then I started wondering how these all resided in the same Changes file -- they must, mustn't they? Is there a paper or something that explains all of this?

It's actually fairly simple. Each project has its associated change set, meaning if you create a new project you also create a new change set. There is always one active change set (called "Smalltalk changes") where currently made changes are being recorded. A change set records _what_ has changed (i.e. a class, a selector in a class etc.) but not _how_ it has changed. This is only contained in the changes file, meaning that if you browse for instance "recent versions" of a method the changes file is scanned backwards for those older versions starting from the current file location of this method. Note that there is a mark in the changes file where a previous version of a particular method may be in the file.

So in the end, there is one change file containing the source of the various changes, a number of change sets hanging around which record what has changed and one active change set. Entering a project will just activate the project's associated change set.

• What is the maximum size of a DoIt? I exceeded it today. I was adding

students to our PWS-based turnin/grading browser, three lines per student and 120 students. When I tried to select and execute the whole block of code, I got an error about "classEncoding not understood" which I didn't understand. I then tried executing the code in three chunks -- and that worked fine. I think I blew up some limit. Where is that limit? Is it something I can change?

I don't really think that this is a limitation unless you've exceeded one of the magical 256 element barriers (such as in inst vars, literals or temps).

Hope this helps. Andreas