Squeak-dev March 1998

squeak-dev@lists.squeakfoundation.org

67 participants
130 discussions

Re: MIDI Socket #?
by Craig Latta 10 Mar '98

10 Mar '98

Cool! I don't know of any opinion on this issue by RFCs, but I've been running MIDI servers which listen for clients on port 7777 (in honor of a certain Urantian friend of mine :), and for other servers (it's a relay architecture) on port 6666 (servers do all the evil stuff :). It tends to be difficult to convince people to run servers on ports less than... oh, I forget... 1024 or something ("reserved ports"). I don't know of any other related work that's open and/or public. I've been meaning to be a more active collaborator on Siren since you announced it a few weeks ago, but I've had my hands full with demos demos demos at work... I should get some isolated free time on the 14th. It sounds like things are very interesting! :) -C -- Craig Latta composer and computer scientist craig.latta(a)netjam.org www.netjam.org latta(a)interval.com Smalltalkers do: [:it | All with: Class, (And love: it)]

2 1

exceptions
by David Farber 09 Mar '98

09 Mar '98

i've coded up an exception mechanism for squeak. it is a port of Bob Hinkle and Ralph Johnson's exception mechanism for V286. one of the big points of this setup is that it is supposed to mimic the ParcPlace (and even Tek) exceptions. is this useful to anyone from the compatibility standpoint? i don't have access to a PP environment, so i can't tell for certain that i haven't introduced some incompatibilty in the translation. it all *seems* to work, but i haven't hammered on it too hard. i am going to wait a bit before i throw it up on UIUC; give it a week or two to let the (inevitable) bugs crawl out. if you are not already familiar with PP's exception mechanism, i don't know how useful this will be to you. 'print' the one-liner examples in the ExceptionCollection class comments to to get a basic idea of what is going on. i'll put together some better documentation before i put it onto UIUC. dave Exceptions.cs ---- Object classPool at: 'ErrorSignal' ifAbsent: [ Object classPool at: 'ErrorSignal' put: nil]! 'From Squeak 1.31 of Feb 4, 1998 on 9 March 1998 at 5:21:33 pm'! Object subclass: #Exception instanceVariableNames: 'signal parameter extraString proceedBlock handlerContext signalContext process ' classVariableNames: 'EmergencyHandler ' poolDictionaries: '' category: 'Exceptions'! OrderedCollection variableSubclass: #ExceptionCollection instanceVariableNames: '' classVariableNames: 'OutOfBoundsError ' poolDictionaries: '' category: 'Exceptions'! Object subclass: #Signal instanceVariableNames: 'parent mayProceed notifierString nameClass nameMessage ' classVariableNames: 'GenericSignal NoHandlerSignal ProceedErrorSignal TimeoutSignal WrongProceedabilitySignal ' poolDictionaries: '' category: 'Exceptions'! !Object methodsFor: 'as yet unclassified'! errorSignal ^self class errorSignal! ! !Exception methodsFor: 'handling' stamp: 'df 3/7/98 16:04'! proceed "Return nil as the value of the raised signal. Unwind the stack up to that point and resume execution in the context that raised the signal." ^self proceedWith: nil! ! !Exception methodsFor: 'handling' stamp: 'df 3/9/98 16:34'! proceedDoing: aBlock | answer | "Return the value of aBlock as the value of the raised signal. Unwind the stack up to that point and resume execution in the context that raised the signal. The comment for the PP version says that 'the block is executed in the handler context of the signaller, so (for example) it can raise a different signal in place of the original one.' I'm not sure exactly what that means, but I think the code below has the effect they're (trying to) describe." proceedBlock isNil ifTrue: [ "If proceedBlock is nil, we're not supposed to proceed on this Signal, so raise a new error." Signal proceedErrorSignal raiseWith: self] ifFalse: [ answer := aBlock value. self unwindLaterContextsFrom: handlerContext. proceedBlock value: answer "The next line is how this branch was implemented originally, but with my implementation it would return *out* of the signalling context (rather than in to it). I don't think I've done anything that would affect this behavior--maybe it was a bug in the original version?" "signalContext returnDoing: aBlock"]! ! !Exception methodsFor: 'handling' stamp: 'df 3/5/98 17:46'! proceedWith: aValue "Return aValue as the value of the raised signal. Unwind the stack up to that point and resume execution in the context that raised the signal." self proceedDoing: [aValue]! ! !Exception methodsFor: 'handling' stamp: 'df 3/4/98 22:59'! reject "Pass the exception on to the next handler." | | self propagatePrivateFrom: handlerContext.! ! !Exception methodsFor: 'handling' stamp: 'df 3/9/98 16:39'! restart "Restart the #handle:do: context." self unwindLaterContextsFrom: handlerContext. handlerContext restart. process := Processor activeProcess. [ "Transcript show: process printString; cr. Transcript show: process suspendedContext printString; cr. Transcript show: handlerContext printString; cr. Transcript show: handlerContext sender printString; cr." process popTo: handlerContext. "Transcript show: process printString; cr. Transcript show: process suspendedContext printString; cr. Transcript show: handlerContext sender printString; cr; cr." process resume.] fork. process suspend. ! ! !Exception methodsFor: 'handling' stamp: 'df 3/9/98 16:07'! restartDo: aBlock "Restart the #handle:do: context, but replace the value of the doBlock (ie, second parameter) with aBlock." handlerContext tempAt: 2 put: aBlock. self restart. ! ! !Exception methodsFor: 'handling' stamp: 'df 3/7/98 16:09'! return "Return nil as the value of the handle:do: message that caught this Exception." self returnWith: nil! ! !Exception methodsFor: 'handling' stamp: 'df 3/9/98 16:40'! returnDoing: aBlock "The stack is unwound to he context of the handle:do message that caught this Exception, at which point aBlock is evaluated and its value returned as the value of the handle:do: message." | answer | answer := aBlock value. self unwindLaterContextsFrom: handlerContext. (handlerContext at: 3) value: answer.! ! !Exception methodsFor: 'handling' stamp: 'df 3/5/98 17:10'! returnWith: aValue "Return aValue as the value of the handle:do: message that caught this Exception." self returnDoing: [aValue]. ! ! !Exception methodsFor: 'public' stamp: 'df 3/7/98 16:02'! defaultHandlerAction: parm "Choose the default handler response." ^self returnWith: parm! ! !Exception methodsFor: 'public' stamp: 'df 3/7/98 16:03'! errorString "Return the error string for this Exception, which is generated by its Signal." ^signal errorStringExtra: extraString with: parameter! ! !Exception methodsFor: 'public' stamp: 'df 3/5/98 16:24'! fetchHandlerBlock: startContext "Find the context of the exception handler block" | aContext | aContext := startContext. [aContext notNil] whileTrue: [(aContext selector == #handle:do:) ifTrue: [handlerContext := aContext. ^aContext tempAt: 1]. aContext := aContext sender]. ^nil! ! !Exception methodsFor: 'public' stamp: 'df 3/7/98 16:04'! parameter ^parameter! ! !Exception methodsFor: 'public' stamp: 'df 3/5/98 17:03'! propagateFrom: startContext "Starting below startContext, look down the call stack to find a handler for this Exception, and execute the handler once you've found it. In the original Tek version this would have been an infinite loop, allowing handlers to pass on control to others without explicitly doing a reject. In PP, though, any handler that doesn't take a positive action is assumed to take a default action, which at this point is a #returnWith:." signalContext := startContext. ^self propagatePrivateFrom: startContext! ! !Exception methodsFor: 'public' stamp: 'df 3/7/98 16:10'! signal "This is the signal whose raising created this exception." ^signal! ! !Exception methodsFor: 'public' stamp: 'df 3/5/98 17:48'! signal: sig parameter: par extraString: str proceedBlock: pb "Initialize the Exception's instance variables. sig is the Signal whose raising created this Exception. par and str are used to generate this Exception's error string. pb is either a block used to proceed or nil, indicating that proceeding isn't allowed." signal := sig. parameter := par. extraString := str. proceedBlock := pb! ! !Exception methodsFor: 'public' stamp: 'df 3/9/98 16:43'! unwindLaterContextsFrom: exContext "" | aContext | aContext := signalContext. [aContext == exContext] whileFalse: [(aContext selector == #valueOnUnwindDo:) ifTrue: [(aContext tempAt:1 ) value] ifFalse: [(aContext selector == #valueNowOrOnUnwindDo:) ifTrue: [(aContext tempAt:1 ) value]]. aContext := aContext sender]. ^nil! ! !Exception methodsFor: 'private' stamp: 'df 3/7/98 16:03'! handlerContext "Return the context of the #handle:do: message that will handle this Exception." ^handlerContext! ! !Exception methodsFor: 'private' stamp: 'df 3/7/98 16:04'! initialContext "Return the context passed into this Exception via the #propagateFrom: message. This is the context where signal was first raised." ^signalContext! ! !Exception methodsFor: 'private' stamp: 'df 3/5/98 17:09'! propagatePrivateFrom: startContext "Starting below startContext, look down the call stack to find a handler for this Exception, and execute the handler once you've found it. This is called from #propagateFrom: and also after a #reject." | result handlerBlock unhandledExc | handlerBlock := self fetchHandlerBlock: startContext. handlerBlock isNil ifFalse: [result := handlerBlock value: self] ifTrue: [(Signal noHandlerSignal accepts: signal) ifTrue: [ "This exception represents an unhandled exception already. It must have been rejected to get down the call stack below Signal>>noHandlerSignal, so just use the EmergencyHandler--that's what it's there for. For an unhandled exception, parameter should be the exception that couldn't be handled originally." ^EmergencyHandler value: parameter value: parameter initialContext] ifFalse: [ "There's no handler for this exception, so raise an unhandled-exception exception. Note that we pass self as the parameter to the new exception, which is why we knew what the value of parameter would be in the comment above." unhandledExc := self class new signal: Signal noHandlerSignal parameter: self extraString: nil proceedBlock: nil. (handlerBlock := unhandledExc fetchHandlerBlock: signalContext) isNil ifTrue: [ "We got trouble!!!! Use the EmergencyHandler again, and tell someone to get an unhandled-exception handler together." ^EmergencyHandler value: self value: signalContext] ifFalse: [result := handlerBlock value: unhandledExc]]]. "If we get here, the selected handler didn't choose a specific option between proceeding, returning, and rejecting, so choose the default response." ^self defaultHandlerAction: result! ! !Exception methodsFor: 'private' stamp: 'df 3/7/98 16:10'! willProceed "This exception can proceed if proceedBlock isn't nil; otherwise proceeding isn't allowed." ^proceedBlock notNil! ! !ExceptionCollection commentStamp: 'df 3/9/98 17:21' prior: 0! Examples: ({1. 2. 3. 4. 5} as: ExceptionCollection) getFifthElement ({1. 2. 3. 4} as: ExceptionCollection) getFifthElement ({1. 2. 3. 4} as: ExceptionCollection) getDoubledFifthElement ({1. 2. 3. 4} as: ExceptionCollection) getForcedFifthElement ! !ExceptionCollection methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 17:41'! at: anIndex "" (self size < anIndex) ifTrue: [^OutOfBoundsError raise] ifFalse: [^super at: anIndex].! ! !ExceptionCollection methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 17:35'! doubledAt: anIndex "" | value | value := (self size < anIndex) ifTrue: [OutOfBoundsError raiseRequest] ifFalse: [super at: anIndex]. ^value * 2 ! ! !ExceptionCollection methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 17:36'! getDoubledFifthElement ^OutOfBoundsError handle: [:exception | exception proceedWith: 5] do: [self doubledAt: 5] ! ! !ExceptionCollection methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 15:45'! getFifthElement ^OutOfBoundsError handle: [:exception | exception returnWith: 'Bob'] do: [self at: 5] ! ! !ExceptionCollection methodsFor: 'as yet unclassified' stamp: 'df 3/9/98 09:41'! getForcedFifthElement ^OutOfBoundsError handle: [:exception | self add: 'Bob'. exception restart] do: [self at: 5] ! ! !Object class methodsFor: 'as yet unclassified'! errorSignal ^ErrorSignal! ! !Exception class methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 16:01'! emergency: exception from: context "Define a default emergency handler. This one is appropriate for development environments, but not for runtime." self halt! ! !Exception class methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 16:01'! emergencyHandler: aBlock "Define an emergency handler for unhandled exceptions." EmergencyHandler := aBlock! ! !Exception class methodsFor: 'as yet unclassified' stamp: 'df 3/7/98 16:02'! initialize "Install the emergency handler" "Exception initialize" self emergencyHandler: [:exception :context | self emergency: exception from: context]! ! !ExceptionCollection class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 17:37'! initialize "comment stating purpose of message" | | OutOfBoundsError := Signal genericSignal newSignal.! ! !Signal methodsFor: 'public-creation' stamp: 'df 3/5/98 17:35'! newSignal "Create a new signal, whose parent is self and whose proceedability is false. Note that basicNew has to be used below, since Signal>>new creates a signal whose parent is Object>>errorSignal." ^self class basicNew parent: self! ! !Signal methodsFor: 'public-creation' stamp: 'df 3/5/98 17:22'! newSignalMayProceed: proceedBoolean "Create a new signal, whose parent is self and whose proceedability is equal to proceedBoolean. Note that basicNew has to be used below, since Signal>>new creates a signal whose parent is Object>>errorSignal." ^self class basicNew parent: self mayProceed: proceedBoolean! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:39'! accepts: aSignal "Answer true if a handler for this Signal should be run to handle aSignal. A Signal will handle any exception raised on itself *or* on one of its children, so accept if self == aSignal, or if aSignal equals one of this Signal's children." | p | ^aSignal == self or: [(p := aSignal parent) notNil and: [self accepts: p]]! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:39'! deepCopy "According to the PP implementation, deepCopying a Signal 'doesn't make any sense.' I'm not sure why, so I'll allow deepCopying for now." "^super deepCopyError" ^super deepCopy! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:40'! errorString "Build the error string from notifierString. Prepend my parent's errorString if notifierString starts with a blank." ^notifierString isNil ifTrue: [parent errorString] ifFalse: [(notifierString isEmpty not and: [ notifierString first = Character space]) ifTrue: [parent errorString, notifierString] ifFalse: [notifierString]]! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:40'! errorStringExtra: aString "Build the error string from aString. Prepend my errorString if aString starts with a blank." ^aString isNil ifTrue: [self errorString] ifFalse: [(aString isEmpty not and: [aString first = Character space]) ifTrue: [self errorString, aString] ifFalse: [aString]]! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:42'! errorStringExtra: aString with: parameter "Build the error string from aString. Append parameter's printString if my error string ends with a blank. They didn't have the check for isEmpty not in the PP version, but it seems necessary to me." | errorString | errorString := self errorStringExtra: aString. ^(errorString isEmpty not and: [errorString last = Character space]) ifTrue: [errorString, parameter printString] ifFalse: [errorString]! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/8/98 21:46'! handle: handlerBlock do: doBlock "Evaluate doBlock. If all goes well, return its value. If an exception occurs than the returned value could be generated by evaluating returnBlock." | returnBlock | thisContext push: nil. thisContext pop. returnBlock := [:value | ^value]. ^doBlock value! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:42'! isClassSignal "Return true if this Signal belongs to a class, which means that it's stored in one of nameClass' class variables and returned (statically) via the method nameMessage. In the PP version they test whether this method returnsStaticVariable; for Tek the closest equivalent seems to be isReturnField. For Digitalk, I just check that nameClass supports nameMessage and that the return from sending nameMessage is this signal." | assoc | ^nameClass notNil and: [(nameClass class includesSelector: nameMessage) and: [(nameClass perform: nameMessage) == self]]! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 17:39'! mayProceed "Answer true if execution can proceed from this signal's context." ^mayProceed! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 17:22'! nameClass: aClass message: aSymbol "nameClass and nameMessage are used in printOn:." nameClass := aClass. nameMessage := aSymbol! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 17:33'! newException "Create a new Exception object. Provided as a method for over-riding." ^Exception new! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 17:23'! notifierString: aString "notifierString is used to generate this Signal's error string, and for printOn:. If aString starts with a blank, this Signal will build its error string by appending aString to this Signal's parent's error string." notifierString := aString! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:43'! parent ^parent! ! !Signal methodsFor: 'public-misc' stamp: 'df 3/5/98 19:44'! printOn: aStream self isClassSignal ifTrue: [aStream nextPutAll: nameClass printString, ' ', nameMessage] ifFalse: [super printOn: aStream. notifierString isNil ifTrue: [aStream nextPutAll: ' with parent: '. parent printOn: aStream] ifFalse: [aStream nextPutAll: ' with notifierString: '. notifierString printOn: aStream]]! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/5/98 19:41'! raise "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. The Exception may not proceed back into this signaller." ^self raiseWith: nil startAbove: thisContext extraString: nil proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/5/98 19:46'! raiseErrorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass aString to the Exception for its error message. The Exception may not proceed back into this signaller." ^self raiseWith: nil startAbove: thisContext extraString: aString proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseReturn "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. The Exception may not proceed back into this signaller." ^self raiseReturnWith: nil startAbove: thisContext extraString: nil proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseReturnErrorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass aString to the Exception for its error message. The Exception may not proceed back into this signaller." ^self raiseReturnWith: nil startAbove: thisContext extraString: aString proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseReturnWith: parameter "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass parameter to the Exception to use as its parameter. The Exception may not proceed back into this signaller." ^self raiseReturnWith: parameter startAbove: thisContext extraString: nil proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseReturnWith: parameter errorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass parameter to the Exception to use as its parameter. Pass aString to the Exception for its error message. The Exception may not proceed back into this signaller." ^self raiseReturnWith: parameter startAbove: thisContext extraString: aString proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseWith: parameter "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass parameter to the Exception to use as its parameter. The Exception may not proceed back into this signaller." ^self raiseWith: parameter startAbove: thisContext extraString: nil proceed: false! ! !Signal methodsFor: 'public-raises' stamp: 'df 3/7/98 17:09'! raiseWith: parameter errorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass parameter to the Exception to use as its parameter. Pass aString to the Exception for its error message. The Exception may not proceed back into this signaller." ^self raiseWith: parameter startAbove: thisContext extraString: aString proceed: false! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:46'! raiseRequest "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. The Exception may proceed back into this signaller." ^self raiseWith: nil startAbove: thisContext extraString: nil proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:46'! raiseRequestErrorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass aString to the Exception for its error message. The Exception may proceed back into this signaller." ^self raiseWith: nil startAbove: thisContext extraString: aString proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:45'! raiseRequestReturn "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. The Exception may proceed back into this signaller." ^self raiseReturnWith: nil startAbove: self thisContext extraString: nil proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:47'! raiseRequestReturnErrorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass aString to the Exception for its error message. The Exception may proceed back into this signaller." ^self raiseReturnWith: nil startAbove: self thisContext extraString: aString proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:47'! raiseRequestReturnWith: parameter "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass parameter to the Exception to use as its parameter. The Exception may proceed back into this signaller." ^self raiseReturnWith: parameter startAbove: self thisContext extraString: nil proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:48'! raiseRequestReturnWith: parameter errorString: aString "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender's home's sender. Pass parameter to the Exception to use as its parameter. Pass aString to the Exception for its error message. The Exception may proceed back into this signaller." ^self raiseReturnWith: parameter startAbove: self thisContext extraString: aString proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/5/98 19:48'! raiseRequestWith: parameter "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass parameter to the Exception to use as its parameter. The Exception may proceed back into this signaller." ^self raiseWith: parameter startAbove: self thisContext extraString: nil proceed: true! ! !Signal methodsFor: 'public-raise requests' stamp: 'df 3/7/98 17:08'! raiseRequestWith: parameter errorString: string "Create an Exception on the receiver and search for a handler. Search for a handler starting at self thisContext's sender. Pass parameter to the Exception to use as its parameter. The Exception may proceed back into this signaller." ^self raiseWith: parameter startAbove: self thisContext extraString: string proceed: true! ! !Signal methodsFor: 'private' stamp: 'df 3/5/98 17:39'! parent: aSignal "Set this Signal's parent to aSignal. This may only be done once. If this Signal is raised, it can be handled by any handler for it *or* one of its ancestors." self parent: aSignal mayProceed: aSignal mayProceed! ! !Signal methodsFor: 'private' stamp: 'df 3/5/98 17:23'! parent: aSignal mayProceed: aBoolean "Set this Signal's parent to aSignal. This may only be done once. If this Signal is raised, it can be handled by any handler for it *or* one of its ancestors." parent notNil ifTrue: [self error: 'Tried to reset a Signal''s parent.'. ^self]. parent := aSignal. mayProceed := aBoolean! ! !Signal methodsFor: 'private' stamp: 'df 3/5/98 19:50'! raiseReturnWith: parameter startAbove: context extraString: str proceed: aBoolean "Create an exception on the receiver. Start looking for a handler in the sender of context's sender's home. Ie, if context is a BlockContext, start looking for a handler in the sender of the method that defines the block executing in context." "In the PP version, they checked to see whether context sender home == nil. This could happen if the block was optimized. Check whether this is possible in Tektronix-land." ^self raiseWith: parameter startingAt: context sender home sender extraString: str proceed: aBoolean! ! !Signal methodsFor: 'private' stamp: 'df 3/4/98 23:27'! raiseWith: parameter startAbove: context extraString: str proceed: aBoolean "Create an exception on the receiver. Start looking for a handler in the sender of context." ^self raiseWith: parameter startingAt: context sender extraString: str proceed: aBoolean! ! !Signal methodsFor: 'private' stamp: 'df 3/4/98 22:15'! raiseWith: parameter startingAt: context extraString: str proceed: aBoolean "Create a new exception and have it look for handlers starting at <context>" | exception | exception := self newException signal: self parameter: parameter extraString: str proceedBlock: (aBoolean ifTrue: [[:value | ^value]] ifFalse: [nil]). ^exception propagateFrom: context! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 17:19'! genericSignal ^GenericSignal! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:36'! initialize "Initialize the Signals provided through this class' instance variables. Signal initialize" | signal | "Create the generic Signal." signal := self basicNew notifierString: 'An unknown Signal with: '; nameClass: self message: #genericSignal. signal parent: nil mayProceed: true. GenericSignal isNil ifTrue: [GenericSignal := signal] ifFalse: [GenericSignal become: signal]. "Create the Signal to handle unhandled exceptions." NoHandlerSignal := GenericSignal newSignal notifierString: 'No handler was found for an Exception: '; nameClass: self message: #noHandlerSignal. "The next Signals will inherit from Object>>errorSignal." signal := Object errorSignal. "The PP version doesn't have this, but it's not clear to me where Object>>errorSignal ever gets initialized!!!!" signal isNil ifTrue: [ ErrorSignal := GenericSignal newSignal notifierString: 'Error - '; nameClass: Object message: #errorSignal. signal := ErrorSignal]. "Create the Signal to handle a proceed in an Exception that can't proceed." ProceedErrorSignal := signal newSignal notifierString: 'A handler tried to proceed from a non-proceedable Exception: '; nameClass: self message: #proceedErrorSignal. "Create the Signal to handle mismatched proceedability." WrongProceedabilitySignal := signal newSignal notifierString: 'The raiser and the Signal do not agree about proceedability: '; nameClass: self message: #wrongProceedabilitySignal. "Create the Signal to handle time-out errors." TimeoutSignal := signal newSignal notifierString: 'Timeout: '; nameClass: self message: #timeoutSignal.! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:36'! new "Return a new signal whose parent is Object>>errorSignal. If you want a signal with some other parent, use Signal class>>basicNew and Signal>>parent:." ^Object errorSignal newSignal! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:37'! noHandlerSignal "This Signal catches unhandled exceptions." ^NoHandlerSignal! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:37'! proceedErrorSignal "This signal catches the event that a handler tries to proceed through a non-proceedable exception." ^ProceedErrorSignal! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:37'! timeoutSignal "This Signal catches timeouts." ^TimeoutSignal! ! !Signal class methodsFor: 'as yet unclassified' stamp: 'df 3/5/98 19:38'! wrongProceedabilitySignal "This signal catches the event when a non-proceedable signal is raised via one of the Signal>>raiseRequest* messages." ^WrongProceedabilitySignal! ! Exception initialize! Signal initialize! ExceptionCollection initialize! -- -- j. david farber oo architect+mentor numenor labs incorporated in sunny boulder colorado dfarber(a)numenor.com www.numenor.com

1 0

Re: Prototypes
by FixPoint 07 Mar '98

07 Mar '98

Hi Ralph, In a message dated 98-03-03 15:45:45 EST, you write: We used it in a Hypercard clone to add behavior to buttons, and in a Alternate Reality Kit clone to add behavior to objects. How do I lay hands on this groovy Alternate Reality Kit? :-) --Sheldon

1 0

Re: Smalltalk object trampling
by Mike Klein 06 Mar '98

06 Mar '98

!SmallInteger methodsFor: 'system primitives' stamp: 'msk 3/6/98 10:59'! spookyNew "Primitive. From Behavior >># basicNew." <primitive: 70> self error: 'rats'! ! 3 spookyNew "Be prepared for sever VM crashage"! 'we wont get here -- Mike Klein'!

1 0

Rookie Response Re: Drawing editor-rookie
by John-Reed Maffeo 06 Mar '98

06 Mar '98

Carolyn, I am also a rookie interested in a Drawing editor on Squeak. I have been working on a port of a Draw80 which was originally written by fellow list member Sam Adams. I have also looked at Hot Draw and Smalldraw which are also available on the archive. None of them will filein to Squeak and run without substantial modifications. (Squeak heros and demigods, please correct me if I am wrong ;) Draw80 is giving me fits because I don't understand the MVC well enough to rewrite the interface yet. The drawing methods also have to be tweaked to get them to run. And I still don't know how to get a picture out of Squeak. There are some references to Postscript in Draw80, but if they need to be fixed I am out of my league. What is you goal? What do you want to do once you have a drawing program running in Squeak? Mr. Adams has hinted that he may have his version of Draw80 ready RSN. I think that the port would be pretty easy for someone who knew what they were doing. But people who know what they are doing probably have more interesting things to do. Best Regards, John-Reed Maffeo > Date: 06 March 1998, 00:17:17 EST > From Juhasz gt2779b at INTERNET > gt2779b(a)prism.gatech.edu > squeak at INTERNET > squeak(a)cs.uiuc.edu > To: squeak at INTERNET > squeak(a)cs.uiuc.edu > cc: recipien at INTERNET > recipient.list.not.shown:@ > > Reply-To squeak at INTERNET > squeak(a)cs.uiuc.edu > Subject: Drawing editor-rookie > > Resent-Date: 6 Mar 1998 05:17:35 -0000 > Mime-Version: 1.0 > Content-Type: text/plain; charset=US-ASCII > Resent-Message-Id: <"0ShYBD.A.tt.mb4_0"@jerry> > X-Loop: squeak(a)cs.uiuc.edu > Precedence: list > Hi, my name is Carolyn and I'm not sure who is reading this but > > here goes: > First off, a thank you to those involved with maintaing the Squeak > web pages. > > I'm a student at Georgia Tech and currently taking a class in Modeling > Design which uses mainly Squeak as out programming tool. For an upcoming > project I have been looking through Smalltalk archives to find a simple > drawing editor that I can download and file in. I'm only looking for one > that has simple functionality (draw a line, erase it, shapes!, etc) > preferably not using Morphic. The proplems are simply I'm geting a little > lost on the web trying to find such a thing, and also we are using > Squeak1.23 so I'm not sure what other code if any is compatible or can be > easily changed. > > Any help would be greatly appreciated. THANKS in advance!!! > > --Carolyn

3 3

PieCharts in Morphic
by Dietmar Krueger 06 Mar '98

06 Mar '98

It would be nice to migrate the PieChart example of Self 4.0 to Morphic. What I need is some lowlevel stuff: The (Form-)Canvas doesnt have a "fillArcWithin: rect From: startAngle Spanning: spanAngle..."-method to draw a pie wedge. Any Suggestions? Or should I draw a pie at a higher level? Greetings Dietmar

1 0

Re: Printing Music Scores (ports of Siren)
by stp＠limbo.create.ucsb.edu 06 Mar '98

06 Mar '98

Richard Smol wrote, > It would be nice if Siren got ported to other OSes aside from MacOS as > well. I would have done a port to Linux and Win32, if only I had > sufficient time and knowledge =( The bulk of Siren is platform-independent. The MIDI driver is being rewritten for improved portability. I'll support Mac and SGI platforms. Andreas Raab has expressed some interest in porting to Windows. ByTheWay, here's the current header file for the MIDI primitives--comments? -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- /*************************************************************** * Header File for the Squeak/Siren Interface to Mac MIDI * Stephen T. Pope -- stp(a)create.ucsb.edu * * Version 1.31b -- New Prim Interface -- 1998.02.25 * * Siren supports up to 256 "logical" MIDI channels. These can be routed to any of 16 I/O * connections, which are usually mapped 1:1 onto hardware or software interfaces (e.g., * QuickTime musical instruments and/or a hardware MIDI interface on a serial port). * User programs can create these mappings in order to set up arbitrary "orchestras" of * "virtual" MIDI instruments. * * There are a number of queries so that Smalltalk MIDI interface ports can determine * the features of a concrete driver (e.g., version, hasBuffer, hasDurations, etc.), and * also several formats of output messages (play-byte-array, play-note) to support many * kinds of MIDI applications. * * FYI: My MIDI set-up consists of a Macintosh PowerBook G3 (using QuickTime MIDI * instruments), an ancient Yamaha FB-01 tone generator, a Yamaha PF70 electric piano * (because of its weighted keyboard), a Peavey PC1600X fader box (16 faders and 16 * buttons), and a Soundcraft mixer to mix the Piano, Mac, and tone generator. * * Open Issues: * * NoteOn/Off are the only MIDI commands that are handled specially. Is there any reason * to extend the interface for sending control messages, programs changes, etc. that's * better than the basic "put" primitives? * * Reading MIDI always returns a raw ByteArray. Should I put a some MIDI command parser * in the primitives and return MIDICommand objects? * * Output of continuous controls involves lots of calls to the output functions. Should * we provide the users with primitives to pass down a function object? * */ /*************************************************************** * * External MIDI interface function prototypes (Smalltalk primitives) */ int sqHasMIDI(void); // Answer whether MIDI driver is loaded (Prim 610) int sqMIDIVersion(void); // Answer the version of the MIDI driver (Prim 611) int sqMIDIHasBuffer(void); // Answer whether the driver has an output buffer (Prim 612) int sqMIDIHasDurs(void); // Answer whether notes can have durations (Prim 613) // (If yes, you can use the play-note command.) int sqMIDIAvailEvents(void); // Answer the number of events in the input Q (Prim 614) int sqOpenMIDI(int cbSemaphore); // Open/start the MIDI interface (Prim 615) // (Answer the number of interfaces found.) int sqCloseMIDI(void); // Close the MIDI interface (Prim 616) void sqFlushMIDI(int both); // Flush the MIDI output queue (Prim 617) // (both = 0 --> flush output only) void sqStartMIDIInput(void); // Start receiving input events (Prim 618) void sqStopMIDIInput(void); // Stop receiving input events (Prim 619) unsigned long sqGetMIDIClock(void); // Answer current clock value (msec) (Prim 620) int sqSetMIDIClock(unsigned long timeValue); // Set clock (msec) (Prim 621) int sqTestMIDI(void); // Play something (random notes) (Prim 622) void sqMIDIAllNotesOff(void); // Stop all notes playing (Prim 623) void sqStartMIDIEcho(void); // Start echoing input events (Prim 624) void sqStopMIDIEcho(void); // Stop echoing input events (Prim 625) int getInterfaceNames(int names); // Get the names of the connected interfaces (Prim 626) // names is interpreted as char ** // Define a mapping between a logical channel and a concrete // interface/channel tuple (Prim 626) int sqMIDIMapLogicalChannel(int logical, int interface, int channel); int sqMIDIClearLogicalChannel(int logical); // Clear a logical channel mapping (Prim 627) int sqMIDIClearChannelMap(void); // Clear all logical channel mappings (Prim 628) // Send bytes out the default port right now (Prim 630) int sqMIDIPut(int message, int length); // message is interpreted as unsigned char * // Send bytes out the given port at some time (Prim 631) int sqMIDIPutOnAt(int message, int length, int interface, int time); // One-call noteOn/Off command (Prim 632) int sqMIDIPlayNote(int channel, int key, int velocity, int time, int dur); int sqReadMIDI(int buffer); // read input into buffer (Prim 635) /******************************************** * END */ -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- stp _ Stephen Travis Pope _ Center for Research in Electronic Art Technology (CREATE) _ Dept. of Music, Univ. of California, Santa Barbara (UCSB) _ stp(a)create.ucsb.edu, http://www.create.ucsb.edu/~stp/

1 0

Re: Printing Music Scores
by stp＠limbo.create.ucsb.edu 06 Mar '98

06 Mar '98

Hello all, Based on this discussion, I thought I should say/write a few words about Siren's GUI framework. It is based on the one used in the MODE, and documented in detail in an article in Computer Music Journal (CMJ) 16:3 (Fall 1992). (This document is included as ASCII in the Siren release's "Siren Doc" archive; a compressed PostScript version [with figures] is to be found in http://www.create.ucsb.edu/~stp/PostScript/IDP.cmj.ps.Z.) MODE/Siren GUI Tools Siren is designed specifically for the easy construction of graphical tools for manipulating sound and music (as well as other complex structured data). There is a sophisticated (IMHO) framework for automatic layout of scores and other event lists. There is a wide array of musical glyphs (including most of the symbols found in standard music fonts). The figures in the CMJ article give examples of the graphical applications I wrote in the MODE. The earlier versions of the tools ("DoubleTalk" and the "HyperScore ToolKit") used "old" MVC. These were ported in the MODE to VisualWorks, meaning that windowSpec methods were used for view creation. Now that the "core" of the package (magnitudes, events, event lists, schedulers, I/O ports, etc.), has been ported to Squeak, I'm getting around to re-writing the GUI framework for Squeak/Morphic. (The basic display list framework works quite well in Squeak already, but runs under old MVC rather than Morphic.) "Navigator" MVC The basic premise of the Siren GUI framework (taken from the "Navigator" application developed at Xerox PARC by David Leibs, Adele Goldberg, and myself based on our eariler systems "DoubleTalk" and "The Delusion of Maya"), is that all applications are simply glorified drawing tools with some smarts about the objects that the user is manipulating. The run-time relationships are somewhat like the following (for a drawing of this, see figure 6 on p. 17 of the CMJ paper): A view has model that's an an event list editor (or other editor). A view has a display list that it displays. (The view's controller uses the display list for hit detection.) An event list editor has a model that's an an event list (or other complex object). An event list editor has a layout manager that it uses to generate the view's display list on demand. A layout manager uses a structure accessor to navigate around the event list. Building a new notation means refining one of the built-in layout manager classes. This might, for example, generate a simple "piano roll" notation using a note's pitch and time to generate its x/y position, and its duration to determine its width (PitchTimeLayoutManager does this). Fancier layout managers can have all sorts of layout rules involving generating graphical symbols for non-playing events (e.g., bar lines) or generating multi-glyph sub-display-lists for each event (e.g., including an accidental). >From the CMJ article: "Much of the work of building a new tool within the MODE often goes into customizing the interaction and manipulation mechanisms, rather than just the layout of standard pluggable view components. Building a new notation by customizing a layout manager class and (optionally) a view and controller, is relatively easy. Adding new structure accessors to present new perspectives of structures based on properties or link types can be used to extend the range of applications and to construct new hypermedia link navigators. This architecture means that views and controllers are extremely generic (applications are modeled as structured graphics editors, or "MacDraw with structures behind it"), and that the bulk of many applications' special functionality resides in a small number of changes to existing accessor and layout manager classes." Status Release 1.31 of Siren includes all the "core" classes ported to Squeak. The Navigator framework works as well (up to the level of display list editors and simple layout managers). The higher-level tools have not yet been ported because I plan to re-think them in the process of moving over to Morphic. (I am chanting the famous Ungar/Smith mantra of "only objects on the screen" and trying to take a less tool-oriented approach, but am having a hard time at it.) I'd love collaborators, and can set up a mechanism for more frequent updates as soon as the next minor release settles. (I've been re-designing MIDI in the past few weeks, and believe I've been able to greatly improve it.) If there's interest, I can set up a special Siren mailing list, or we can keep this discussion on the Squeak list for the time being... stp _ Stephen Travis Pope _ Center for Research in Electronic Art Technology (CREATE) _ Dept. of Music, Univ. of California, Santa Barbara (UCSB) _ stp(a)create.ucsb.edu, http://www.create.ucsb.edu/~stp/

1 0

Drawing editor-rookie
by Juhasz 06 Mar '98

06 Mar '98

Hi, my name is Carolyn and I'm not sure who is reading this but here goes: First off, a thank you to those involved with maintaing the Squeak web pages. I'm a student at Georgia Tech and currently taking a class in Modeling Design which uses mainly Squeak as out programming tool. For an upcoming project I have been looking through Smalltalk archives to find a simple drawing editor that I can download and file in. I'm only looking for one that has simple functionality (draw a line, erase it, shapes!, etc) preferably not using Morphic. The proplems are simply I'm geting a little lost on the web trying to find such a thing, and also we are using Squeak1.23 so I'm not sure what other code if any is compatible or can be easily changed. Any help would be greatly appreciated. THANKS in advance!!! --Carolyn

1 0

Re: Squeak on Solaris/olvwm
by Mike Klein 06 Mar '98

06 Mar '98

I've narrowed the hanging problem down to olvwm. I switched to fvwm, and the problem went away. Unfortunately, I hate fvwm. Fortunately, I only will have to use it to open the Squeak screen. I can't wait to start doing some real Squeak hacking. Anybody out there using olvwm? -- Mike Klein > On Wed, 4 Mar 1998, Mike Klein wrote: > > > By the way, is anyone out there using Squeak on Solaris? > > I am using olvwm. > > Is anyone who is having problems with the VM hanging and screen not updating? > > The VM hang is "cured" by having the (OS-window/Squeak-Screen) lose and then > > regain focus. (The squeak screen still needs refreshing).

1 0

← Newer
1
...
6
7
8
9
10
11
12
13
Older →