April 2011 - Pharo-dev - lists.pharo.org

[Pharo-project] Improving Pharo's Exception Hierarchy

by Sven Van Caekenberghe

Hi All, I have this idea that I would like to discuss on the next Pharo sprint and maybe start to implement if there is some consensus on it. It has been mentioned many times before on this list that Object>>#error: should be replaced by signalling specific Exceptions in as many cases as possible (or where it makes sense). Even today, there was http://code.google.com/p/pharo/issues/detail?id=3987 ! I think the core system should set the example here, by defining a number of general purpose exceptions and by using them. Going over #error: senders will be a lot of work but can be done in incremental/Pharo steps. So I went over the current hierarchy, scanned quickly through their references and some #error: senders by fundamental classes and looked at some other Smalltalks. I came up with the following very rough draft of an extended hierarchy (** marks new exceptions). In between brackets are the instance variables. Of course, we have to discuss about naming, instance variables and opportunities for reuse and inheritance (could be fun). I am no expert on exceptions and would certainly like to learn more. I am probably overlooking some aspects. We have to keep this Smalltalk like, flexible, dynamic, not start mimicing other languages. Any step in this direction will be an improvement over the current situation. Really using them correctly throughout the system will take some time. Defining the hierarchy could be done rather quickly. Refactoring is always possible later on. Exception (messageText) Abort Error ArithemticError ZeroDivide (dividend) FloatingPointException RangeError ** (from, to) NaNError ** FileStreamException (fileName) FileDoesNotExistException (readOnly) FileExistsException (fileClass) CannotDeleteFileException FileWriteError FileReadError ** FileClosedException ** CannotAccessFileException ** ReadonlyFileException ** MessageNotUnderstood (message, receiver) NonBooleanReceiver (object) OutOfMemory Halt AssertionFailure BreakPoint SyntaxError ** !exists! (input, position) NumberFormatException ** HeadlessError ** TimedOut ** (object, operation, timeout) VerificationException IllegalOperation ** (operation, object) SizeMismatch (objects) LowMemory ** (percentageFree) SubclassResponsibility ** (message, receiver) NotYetImplemented ** (message, receiver) CannotInstanciate ** (class) ReadOnlyObject ** (object) OutOfFreeSpace ** (object, size) InvalidArgument ** (message, receiver, argument) NotIndexable ** (object) NoKeyedAccess ** (object) NonIntegerIndex ** (receiver, index) SubscriptOutOfBounds ** (receiver, index, from, to) NotFoundException ** (receiver, object) KeyNotFound ** ValueNotFound ** ElementNotFound ** StreamException (stream) PositionError ** (index, from, to) EndOfStream ** BeginOfStream ** All feedback is welcome. Regards, Sven

April 11, 2011

Re: [Pharo-project] Issue 3988 in pharo: Debugger cannot open because of Decompiler assertion failure

by pharo＠googlecode.com

Updates: Status: FixProposed Comment #1 on issue 3988 by nicolas....(a)gmail.com: Debugger cannot open because of Decompiler assertion failure http://code.google.com/p/pharo/issues/detail?id=3988 Name: SLICE-Issue-3988-DebuggerCannotOpenBecauseOfDecompilerAssertionFailure-nice.1 Dependencies: Compiler-nice.282 This is the fix from squeak (Compiler.nice.130)

April 11, 2011

[Pharo-project] Issue 3988 in pharo: Debugger cannot open because of Decompiler assertion failure

by pharo＠googlecode.com

Status: Accepted Owner: nicolas....(a)gmail.com Labels: Type-Squeak New issue 3988 by nicolas....(a)gmail.com: Debugger cannot open because of Decompiler assertion failure http://code.google.com/p/pharo/issues/detail?id=3988 This was reported at http://bugs.squeak.org/view.php?id=7467 If you try to debug this, then your image might hang: '1 0' readStream in: [ :input | | i | [ input skipSeparators. i := Integer readFrom: input. i = 0 ] whileFalse: [ | k count digits | k := 1. count := 0. digits := Array new: 10 withAll: 0. [ count < i ] whileTrue: [ | index1 ps | ps := k printString. ((index1 := ps indexOf: $1) = 0 or: [ (ps indexOf: $3 startingAt: index1) = 0 ]) ifTrue: [ count := count + 1. ps do: [ :each | digits at: each asciiValue - 47 put: (digits at: each asciiValue - 47) + 1 ] ]. k := k + 1 ]. self halt ] ]

April 11, 2011

Re: [Pharo-project] Issue 3982 in pharo: Error: can''t find EOCD position

by pharo＠googlecode.com

Comment #4 on issue 3982 by vonbecm...(a)gmail.com: Error: can''t find EOCD position http://code.google.com/p/pharo/issues/detail?id=3982 i tried again several times, and now it works. Sorry, i cannot reproduce it anymore. you can close it.

April 11, 2011

Re: [Pharo-project] Issue 3818 in pharo: CommandLine Manager

by pharo＠googlecode.com

Updates: Cc: -tristan....(a)gmail.com Comment #5 on issue 3818 by stephane...(a)gmail.com: CommandLine Manager http://code.google.com/p/pharo/issues/detail?id=3818 (No comment was entered for this change.)

April 11, 2011

Re: [Pharo-project] Issue 3818 in pharo: CommandLine Manager

by pharo＠googlecode.com

Updates: Status: Started Comment #4 on issue 3818 by marcus.d...(a)gmail.com: CommandLine Manager http://code.google.com/p/pharo/issues/detail?id=3818 (No comment was entered for this change.)

April 11, 2011

Re: [Pharo-project] Issue 3818 in pharo: CommandLine Manager

by pharo＠googlecode.com

Comment #3 on issue 3818 by marcus.d...(a)gmail.com: CommandLine Manager http://code.google.com/p/pharo/issues/detail?id=3818 So I am checking this. For testing, I made a tt.st that just does "Smalltalk quitPrimitive!". I tested it, works: ./Squeak\ 4.2.5beta1U.app/Contents/MacOS/Squeak\ VM\ Opt PharoCore-1.3.image tt.st Now I load the SLICE. Result: script is *not* executed anymore. So there is something not working.

April 11, 2011

Re: [Pharo-project] Issue 2703 in pharo: Unicode experiments of nicolas cellier on squeak

by pharo＠googlecode.com

Updates: Labels: Milestone-1.3 Comment #6 on issue 2703 by marcus.d...(a)gmail.com: Unicode experiments of nicolas cellier on squeak http://code.google.com/p/pharo/issues/detail?id=2703 (No comment was entered for this change.)

April 11, 2011

Re: [Pharo-project] Issue 3088 in pharo: MNU Text>>withBlanksTrimmed

by pharo＠googlecode.com

Updates: Status: Closed Comment #12 on issue 3088 by marcus.d...(a)gmail.com: MNU Text>>withBlanksTrimmed http://code.google.com/p/pharo/issues/detail?id=3088 In 13140 this expression: SourcedMethodReference allInstances select: [:each | each stringVersion class == Text ] now returns an epmpty array. I think the image recompile fixed it.

April 11, 2011

Re: [Pharo-project] Issue 2986 in pharo: DemoMode should not change Fonts only sizes

by pharo＠googlecode.com

Updates: Status: FixToInclude Comment #8 on issue 2986 by marcus.d...(a)gmail.com: DemoMode should not change Fonts only sizes http://code.google.com/p/pharo/issues/detail?id=2986 (No comment was entered for this change.)

April 11, 2011