Squeak-dev October 2016

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40 participants
114 discussions

How to create a 'Hello world' example for environments
by Chris Cunnington 03 Oct '16

03 Oct '16

>I can confirm that this works. Curious, it seems like >#evaluate:environment: implicitly looks up names in the default >Environment as a fallback. The created WbSrvr Environment does not >have a binding for Object: > env valueOf: #Object => nil. >But: > Compiler evaluate: 'Object' environment: env => Object > Compiler evaluate: 'Object environment' environment: env => Smalltalk > Compiler evaluate: 'WebServer environment' environment: env => WbSrvr >That is probably the kind of stuff that must be documented. I don't know that it's a fallback. I think an Environment only has access to the policy you give it. More specifically to what the Compiler is allowed to see. And an Environment cannot exist without being compiled. I think that's what the binding policy is. In Nicolas's example he had: spanish := Environment withName: 'Spanish'. spanish importSelf. spanish from: english import: #Transcript. I think the #importSelf creates an AllNamePolicy and the #from:import: an ExplicitNamePolicy. If you take the last line out (#from:import:) his example works just the same. I don't think you need to specify you want Transcript. The compiler can see it already from the #importSelf in the AllNamePolicy. So, your three examples basically make sense to me. I think your line of reasoning is solid, though, because understanding the nature of the barrier between Environments is both essential and at the moment pretty hazy. I just want to say 'fallback' may be the wrong word. It can only fall back on any policy it's given and AllNamePolicy doesn't sound too discriminating. I think that may be what's happening. I guess the compiler doesn't check to see if what you want to do is possible. It just plays along or shrugs. If there were tests for an Environment or the the compiler acted like C and said "I see what you're trying to do there, but that's not going to happen." Then the nature of the barrier between environments would become tactile. The errors would teach the nature of the barrier. >As for the "for added fun" part: In my image there is no accessor for >the Process environment (and it is not a fully-fledged Environment >instance, but a Dictionary, when you use Process>>environmentAt: and >friends), so I had to add that accessor myself. Right, yea. Exactly. I just used the "add accessors" menu item to add it. I noticed somebody wrote into Process an #env ivar already, and it looked unused, so I supposed I could employ it when each process is initialized. Then I could inspect a process in the ProcessBrowser. Your change to Compiler>>evaluteCue:ifFail: looks great. I'm looking forward to trying that out. I had a feeling that if I threw that question out there that a better programmer could solve that. Chris

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Re: [squeak-dev] How to create a 'Hello world' example for environments
by Jakob Reschke 03 Oct '16

03 Oct '16

Hi Chris, I can confirm that this works. Curious, it seems like #evaluate:environment: implicitly looks up names in the default Environment as a fallback. The created WbSrvr Environment does not have a binding for Object: env valueOf: #Object => nil. But: Compiler evaluate: 'Object' environment: env => Object Compiler evaluate: 'Object environment' environment: env => Smalltalk Compiler evaluate: 'WebServer environment' environment: env => WbSrvr That is probably the kind of stuff that must be documented. As for the "for added fun" part: In my image there is no accessor for the Process environment (and it is not a fully-fledged Environment instance, but a Dictionary, when you use Process>>environmentAt: and friends), so I had to add that accessor myself. Anyway, while the names in the compiled string are evaluated in the given Environment (including the implicit fallback), the `Environment current` placed in Process class>>forContext:priority: will search the dynamic environment. But #evaluate:environment: does not seem to install an appropriate Exception handler for CurrentEnvironment, so Environment current will return the default Smalltalk Envirionment. If I change the invocation in Compiler>>evaluteCue:ifFail: to [value := cue receiver withArgs: (cue context ifNil: [#()] ifNotNil: [{cue context}]) executeMethod: method] on: CurrentEnvironment do: [:n | n resume: aCue environment]. then the WbSrvr process does get WbSrvr as its environment. Best regards, Jakob 2016-10-03 0:07 GMT+02:00 Chris Cunnington <brasspen(a)gmail.com>: > I not sure if I've gone off the rails here, but it keeps working for me. > > Chris > > > "acquire a Squeak6.0alpha and create an Environment" > env := Environment withName: 'WbSrvr'. > env importSelf. > > "load WebClient-Core into Environment" > chunkcode := ReadWriteStream on: (String new: 1000). > SystemOrganizer default fileOutCategory: 'WebClient-Core' on: chunkcode > initializing: true. > chunkcode reset. > env fileIn: chunkcode announcing: 'Load Environment'. > > "start WebServer in environment" > Compiler evaluate: 'WebServer exampleBrowse' environment: env. > > "go to WebServer class>exampleBrowse in a Browser and change port to > 8888, then start" > WebServer exampleBrowse > > "open tabs in" > http://localhost:9999 > http://localhost:8888 > > "to see the port in the Environment is still 9999" > env explore. > "highlight WebServer in #declarations and explore" > self class methodDictionary > "toggle #exampleBrowse and see the port is 9999" > > "for added fun, go to Process class>>#forContext:priority: and add" > newProcess env: Environment current. > > "start again from the top, this time, explore the WebServer processes in > ProcessBrowser to see both Environments are Smalltalk. I have no idea > what that means. I would have thought the WebServer instance started > with WbSrvr environment would be in a WbSrvr process." > > >

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How to create a 'Hello world' example for environments
by Chris Cunnington 03 Oct '16

03 Oct '16

I not sure if I've gone off the rails here, but it keeps working for me. Chris "acquire a Squeak6.0alpha and create an Environment" env := Environment withName: 'WbSrvr'. env importSelf. "load WebClient-Core into Environment" chunkcode := ReadWriteStream on: (String new: 1000). SystemOrganizer default fileOutCategory: 'WebClient-Core' on: chunkcode initializing: true. chunkcode reset. env fileIn: chunkcode announcing: 'Load Environment'. "start WebServer in environment" Compiler evaluate: 'WebServer exampleBrowse' environment: env. "go to WebServer class>exampleBrowse in a Browser and change port to 8888, then start" WebServer exampleBrowse "open tabs in" http://localhost:9999 http://localhost:8888 "to see the port in the Environment is still 9999" env explore. "highlight WebServer in #declarations and explore" self class methodDictionary "toggle #exampleBrowse and see the port is 9999" "for added fun, go to Process class>>#forContext:priority: and add" newProcess env: Environment current. "start again from the top, this time, explore the WebServer processes in ProcessBrowser to see both Environments are Smalltalk. I have no idea what that means. I would have thought the WebServer instance started with WbSrvr environment would be in a WbSrvr process."

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Daily Commit Log
by commits＠source.squeak.org 02 Oct '16

02 Oct '16

Changes to Trunk (http://source.squeak.org/trunk.html) in the last 24 hours: http://lists.squeakfoundation.org/pipermail/packages/2016-October/068990.ht… Name: Kernel-nice.1044 Ancestors: Kernel-nice.1043 Fix two more problems with nthRoot: 1) last fix introduced a possibility of infinite loop where guess and nextGuess would alternate around the solution 2) contrarily to what was written in comment, the result was not rounded to nearest Float but subject to double-rounding problem. ============================================= http://lists.squeakfoundation.org/pipermail/packages/2016-October/068991.ht… Name: KernelTests-nice.313 Ancestors: KernelTests-mt.311 Test edge cases of Integer>>nthRoot: =============================================

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Re: [squeak-dev] The Trunk: Kernel-nice.1043.mcz
by David T. Lewis 02 Oct '16

02 Oct '16

On Sat, Oct 01, 2016 at 08:19:27PM +0000, commits(a)source.squeak.org wrote: > Nicolas Cellier uploaded a new version of Kernel to project The Trunk: > http://source.squeak.org/trunk/Kernel-nice.1043.mcz > > ==================== Summary ==================== > > Name: Kernel-nice.1043 > Author: nice > Time: 1 October 2016, 10:19:12.37443 pm > UUID: d29f9c07-edc8-4add-9b99-e889fd2be32a > Ancestors: Kernel-nice.1042 > > Fix (10 raisedTo: 600) nthRoot: 300. > It did incorrectly return 126.0 instead of 100. > Can you say anything about the underlying cause of this problem? I saw it in my 64-bit image, but not in my 32-bit image. The Kernel-nice.1042 update resolved the problem in my 64-bit image, but I find that when I revert to Kernel-tfel.1040, the problem does not come back. Strange... Thanks, Dave

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The Trunk: KernelTests-nice.313.mcz
by commits＠source.squeak.org 02 Oct '16

02 Oct '16

Nicolas Cellier uploaded a new version of KernelTests to project The Trunk: http://source.squeak.org/trunk/KernelTests-nice.313.mcz ==================== Summary ==================== Name: KernelTests-nice.313 Author: nice Time: 2 October 2016, 3:19:37.781599 pm UUID: e6139cfd-b985-42d5-9f24-ffeb0ce8cf6c Ancestors: KernelTests-mt.311 Test edge cases of Integer>>nthRoot: =============== Diff against KernelTests-mt.311 =============== Item was added: + ----- Method: IntegerTest>>testNthRootExactnessForHugeValue (in category 'tests - mathematical functions') ----- + testNthRootExactnessForHugeValue + self assert: ((10 raisedTo: 600) nthRoot: 300) classAndValueEquals: 100. + self assert: ((10 raisedTo: 600) + 1 nthRoot: 300) classAndValueEquals: 100.0! Item was added: + ----- Method: IntegerTest>>testNthRootImmuneToDoubleRounding (in category 'tests - mathematical functions') ----- + testNthRootImmuneToDoubleRounding + "Use a specially crafted number for causing double rounding. + Solution is 10...01.1 - verySmallQuantity. + Where verySmallQuantity is approximately 1/53/(1<<53). + If the verySmallQuantity is not taken into account, then solution is rounded to 10....010" + | exponent crafted root highPrecisionRoot | + exponent := 4. + crafted := (1 << Float precision + 3 raisedTo: exponent) - 1. + root := crafted nthRoot: exponent. + highPrecisionRoot := (crafted << (exponent squared * Float precision * 4) nthRootRounded: exponent) / (1 << (exponent * Float precision * 4)). + self assert: (root asFraction - highPrecisionRoot) abs < (root predecessor asFraction - highPrecisionRoot) abs. + + "Same with the other sign. + Solution is 10...00.1 + verySmallQuantity." + crafted := (1 << Float precision + 1 raisedTo: exponent) + 1. + root := crafted nthRoot: exponent. + highPrecisionRoot := (crafted << (exponent squared * Float precision * 4) nthRootRounded: exponent) / (1 << (exponent * Float precision * 4)). + self assert: (root asFraction - highPrecisionRoot) abs < (root successor asFraction - highPrecisionRoot) abs.!

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The Trunk: Kernel-nice.1044.mcz
by commits＠source.squeak.org 02 Oct '16

02 Oct '16

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.1044.mcz ==================== Summary ==================== Name: Kernel-nice.1044 Author: nice Time: 2 October 2016, 3:14:21.098209 pm UUID: ee2cb17e-948a-4227-836c-bcb58e3f26c7 Ancestors: Kernel-nice.1043 Fix two more problems with nthRoot: 1) last fix introduced a possibility of infinite loop where guess and nextGuess would alternate around the solution 2) contrarily to what was written in comment, the result was not rounded to nearest Float but subject to double-rounding problem. =============== Diff against Kernel-nice.1043 =============== Item was changed: ----- Method: Integer>>nthRoot: (in category 'mathematical functions') ----- nthRoot: aPositiveInteger "Answer the nth root of the receiver. Answer an Integer if root is exactly this Integer, else answer the Float nearest the exact root." + | guess excess scaled nBits | - | guess p | - guess := self nthRootRounded: aPositiveInteger. + excess := (guess raisedTo: aPositiveInteger) - self. + excess = 0 ifTrue: [ ^ guess ]. - (guess raisedTo: aPositiveInteger) = self - ifTrue: [ ^ guess ]. + nBits := Float precision - guess highBitOfMagnitude. + nBits <= 0 ifTrue: [ ^(Fraction numerator: guess * 4 - excess sign denominator: 4) asFloat]. - p := Float precision - guess highBitOfMagnitude. - p < 0 ifTrue: [ ^ guess asFloat ]. + scaled := self << (nBits * aPositiveInteger). + guess := scaled nthRootRounded: aPositiveInteger. + excess := (guess raisedTo: aPositiveInteger) - scaled. + ^(Fraction numerator: guess * 4 - excess sign denominator: 1 << (nBits + 2)) asFloat! - guess := self << (p * aPositiveInteger) nthRootRounded: aPositiveInteger. - ^(guess / (1 << p)) asFloat! Item was changed: ----- Method: Integer>>nthRootTruncated: (in category 'mathematical functions') ----- nthRootTruncated: aPositiveInteger "Answer the integer part of the nth root of the receiver." | guess guessToTheNthMinusOne nextGuess | self = 0 ifTrue: [^0]. self negative ifTrue: [aPositiveInteger even ifTrue: [ ArithmeticError signal: 'Negative numbers don''t have even roots.' ]. ^(self negated nthRootTruncated: aPositiveInteger) negated]. guess := 1 bitShift: self highBitOfMagnitude + aPositiveInteger - 1 // aPositiveInteger. [ guessToTheNthMinusOne := guess raisedTo: aPositiveInteger - 1. nextGuess := (aPositiveInteger - 1 * guess * guessToTheNthMinusOne + self) // (guessToTheNthMinusOne * aPositiveInteger). + nextGuess >= guess ] whileFalse: - nextGuess = guess ] whileFalse: [ guess := nextGuess ]. ( guess raisedTo: aPositiveInteger) > self ifTrue: [ guess := guess - 1 ]. ^guess!

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Re: [squeak-dev] Environment declarations vs bindings
by Jakob Reschke 02 Oct '16

02 Oct '16

2016-10-02 1:42 GMT+02:00 Stéphane Rollandin <lecteur(a)zogotounga.net>: > We need to RTFM. Apparently, we first have to WTFM (or expand and refactor it at least). What is already there are the class comment in Environment and these Wiki pages: http://wiki.squeak.org/squeak/6218 http://wiki.squeak.org/squeak/6219 http://wiki.squeak.org/squeak/6220 ...and some mailing list threads that contain previous discussions or code snippets: http://forum.world.st/Environments-td4636629.html http://forum.world.st/The-Inbox-Monticello-fbs-581-mcz-td4731884.html (...and probably others...) But for various reasons already mentioned, that did not suffice for me to get started using Environments, and it seems I am not the only one. Besides, I do not consider the mailing list archives a good place for documentation, especially if one does not know the right search keywords. Jakob

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Daily Commit Log
by commits＠source.squeak.org 01 Oct '16

01 Oct '16

Changes to Trunk (http://source.squeak.org/trunk.html) in the last 24 hours: http://lists.squeakfoundation.org/pipermail/packages/2016-October/068989.ht… Name: Kernel-nice.1043 Ancestors: Kernel-nice.1042 Fix (10 raisedTo: 600) nthRoot: 300. It did incorrectly return 126.0 instead of 100. =============================================

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The Trunk: Kernel-nice.1043.mcz
by commits＠source.squeak.org 01 Oct '16

01 Oct '16

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.1043.mcz ==================== Summary ==================== Name: Kernel-nice.1043 Author: nice Time: 1 October 2016, 10:19:12.37443 pm UUID: d29f9c07-edc8-4add-9b99-e889fd2be32a Ancestors: Kernel-nice.1042 Fix (10 raisedTo: 600) nthRoot: 300. It did incorrectly return 126.0 instead of 100. =============== Diff against Kernel-nice.1042 =============== Item was changed: ----- Method: Integer>>nthRootTruncated: (in category 'mathematical functions') ----- nthRootTruncated: aPositiveInteger "Answer the integer part of the nth root of the receiver." + | guess guessToTheNthMinusOne nextGuess | - | guess guessToTheNthMinusOne delta | self = 0 ifTrue: [^0]. self negative ifTrue: [aPositiveInteger even ifTrue: [ ArithmeticError signal: 'Negative numbers don''t have even roots.' ]. ^(self negated nthRootTruncated: aPositiveInteger) negated]. guess := 1 bitShift: self highBitOfMagnitude + aPositiveInteger - 1 // aPositiveInteger. [ guessToTheNthMinusOne := guess raisedTo: aPositiveInteger - 1. + nextGuess := (aPositiveInteger - 1 * guess * guessToTheNthMinusOne + self) // (guessToTheNthMinusOne * aPositiveInteger). + nextGuess = guess ] whileFalse: + [ guess := nextGuess ]. + ( guess raisedTo: aPositiveInteger) > self ifTrue: - delta := (guess * guessToTheNthMinusOne - self) // (guessToTheNthMinusOne * aPositiveInteger). - delta = 0 ] whileFalse: - [ guess := guess - delta ]. - ( (guess := guess - 1) raisedTo: aPositiveInteger) > self ifTrue: [ guess := guess - 1 ]. ^guess!

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