Squeak-dev October 2011

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The Trunk: Kernel-nice.635.mcz
by commits＠source.squeak.org 14 Oct '11

14 Oct '11

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.635.mcz ==================== Summary ==================== Name: Kernel-nice.635 Author: nice Time: 14 October 2011, 9:48:14.9 pm UUID: b27ad01f-a82e-460f-8cc5-578ea8a77972 Ancestors: Kernel-nice.634 Integrate great changes Juan made in Cuis: - make #sqrt exact when possible. - compute #nthRoot: =============== Diff against Kernel-nice.634 =============== Item was added: + ----- Method: Float class>>maxExactInteger (in category 'constants') ----- + maxExactInteger + "Answer the biggest integer such that it is exactly represented in a float, and all smaller integers also are" + ^1 bitShift: self precision! Item was added: + ----- Method: Float>>nthRoot: (in category 'mathematical functions') ----- + nthRoot: aPositiveInteger + "Answer the nth root of the receiver." + aPositiveInteger = 2 ifTrue: [ + ^self sqrt ]. + + (aPositiveInteger isInteger not or: [ aPositiveInteger negative ]) + ifTrue: [^ ArithmeticError signal: 'nth root only defined for positive Integer n.']. + + ^self negative + ifTrue: [ + aPositiveInteger odd + ifTrue: [ (self negated raisedTo: 1.0 / aPositiveInteger) negated ] + ifFalse: [ ArithmeticError signal: 'Negative numbers don''t have even roots.' ]] + ifFalse: [ self raisedTo: 1.0 / aPositiveInteger ]! Item was added: + ----- Method: Fraction>>nthRoot: (in category 'mathematical functions') ----- + nthRoot: aPositiveInteger + "Answer the nth root of the receiver." + + | d n | + n := numerator nthRoot: aPositiveInteger. + d := denominator nthRoot: aPositiveInteger. + "The #sqrt method in integer will only answer a Float if there's no exact square root. + So, we need a float anyway." + (n isInfinite or: [ d isInfinite ]) ifTrue: [ + ^self asFloat nthRoot: aPositiveInteger ]. + ^n / d! Item was added: + ----- Method: Fraction>>sqrt (in category 'mathematical functions') ----- + sqrt + | d n | + n := numerator sqrt. + d := denominator sqrt. + "The #sqrt method in integer will only answer a Float if there's no exact square root. + So, we need a float anyway." + (n isInfinite or: [ d isInfinite ]) ifTrue: [ + ^self asFloat sqrt ]. + ^n / d! Item was added: + ----- Method: Integer>>nthRoot: (in category 'mathematical functions') ----- + nthRoot: aPositiveInteger + "Answer the nth root of the receiver." + + | selfAsFloat floatResult guess raised higher lower delta | + selfAsFloat := self asFloat. + floatResult := selfAsFloat nthRoot: aPositiveInteger. + + "If we can't do Float arithmetic, currently we can't look for an exact answer" + floatResult isInfinite ifTrue: [ + ^floatResult ]. + + guess := floatResult rounded. + + "If got an exact answer, answer it." + raised := guess raisedToInteger: aPositiveInteger. + raised = self + ifTrue: [ ^ guess ]. + + "In this case, maybe it failed because we are such a big integer that the Float + method gets inexact, even if we are a whole square number. + Note (jmv): The algorithms I found for computing the nthRoot would havily use + very large fractions. I wrote this one, that doesn't create fractions." + selfAsFloat abs >= (Float maxExactInteger asFloat raisedToInteger: aPositiveInteger) + ifTrue: [ + raised > self + ifTrue: [ + higher := guess. + delta := floatResult predecessor - floatResult. + [ + floatResult := floatResult + delta. + lower := floatResult rounded. + (lower raisedToInteger: aPositiveInteger) > self ] whileTrue: [ + delta := delta * 2. + higher := lower ] ] + ifFalse: [ + lower := guess. + delta := floatResult successor - floatResult. + [ + floatResult := floatResult + delta. + higher := floatResult rounded. + (higher raisedToInteger: aPositiveInteger) < self ] whileTrue: [ + delta := delta * 2. + lower := higher ]]. + [ higher - lower > 1 ] whileTrue: [ + guess := lower + higher // 2. + raised := guess raisedToInteger: aPositiveInteger. + raised = self + ifTrue: [ + ^ guess ]. + raised > self + ifTrue: [ higher := guess ] + ifFalse: [ lower := guess ]]]. + + "We need an approximate result" + ^floatResult! Item was added: + ----- Method: Integer>>sqrt (in category 'mathematical functions') ----- + sqrt + "Answer the square root of the receiver." + + | selfAsFloat floatResult guess | + selfAsFloat := self asFloat. + floatResult := selfAsFloat sqrt. + + floatResult isInfinite ifFalse: [ + guess := floatResult truncated. + + "If got an exact answer, answer it. Otherwise answer float approximate answer." + guess squared = self + ifTrue: [ ^ guess ]]. + + "In this case, maybe it failed because we are such a big integer that the Float method becomes + inexact, even if we are a whole square number. So, try the slower but more general method" + selfAsFloat >= Float maxExactInteger asFloat squared + ifTrue: [ + guess := self sqrtFloor. + guess * guess = self ifTrue: [ + ^guess ]]. + + "We need an approximate result" + ^floatResult! Item was added: + ----- Method: LargeNegativeInteger>>sqrt (in category 'mathematical functions') ----- + sqrt + "Answer the square root of the receiver." + ^ DomainError signal: 'sqrt undefined for number less than zero.'! Item was added: + ----- Method: LargePositiveInteger>>mightBeASquare (in category 'mathematical functions') ----- + mightBeASquare + "In base 16, a square number can end only with 0,1,4 or 9 and + - in case 0, only 0,1,4,9 can precede it, + - in case 4, only even numbers can precede it. + See http://en.wikipedia.org/wiki/Square_number + So, in hex, the last byte must be one of: + 00 + 10 + 40 + 90 + x1 + e4 + x9 + where x is any hex digit and e is any even digit + " + | lsb | + lsb := self digitAt: 1. + ^((lsb bitAnd: 7) = 1 "any|1 or any|9" + or: [(lsb bitAnd: 31) = 4 "even|4" + or: [(lsb bitAnd: 127) = 16 "10 or 90" + or: [(lsb bitAnd: 191) = 0]]]) "00 or 40"! Item was added: + ----- Method: LargePositiveInteger>>sqrt (in category 'mathematical functions') ----- + sqrt + "If we know for sure no exact solution exists, then just answer the cheap float approximation without wasting time." + self mightBeASquare ifFalse: [ + ^self asFloat sqrt ]. + + "If some exact solution might exist, call potentially expensive super" + ^super sqrt! Item was added: + ----- Method: Number>>nthRoot: (in category 'mathematical functions') ----- + nthRoot: aPositiveInteger + "Answer the nth root of the receiver." + + self subclassResponsibility! Item was changed: ----- Method: Number>>raisedTo: (in category 'mathematical functions') ----- raisedTo: aNumber "Answer the receiver raised to aNumber." + aNumber isInteger ifTrue: [ + "Do the special case of integer power" - aNumber isInteger ifTrue: - ["Do the special case of integer power" ^ self raisedToInteger: aNumber]. + aNumber isFraction ifTrue: [ + "Special case for fraction power" + ^ (self nthRoot: aNumber denominator) raisedToInteger: aNumber numerator ]. + self < 0 ifTrue: [ + ^ ArithmeticError signal: 'Negative numbers can''t be raised to float powers.' ]. - self < 0 ifTrue: - [ self error: self printString, ' raised to a non-integer power' ]. 0 = aNumber ifTrue: [^ self class one]. "Special case of exponent=0" 1 = aNumber ifTrue: [^ self]. "Special case of exponent=1" 0 = self ifTrue: [ "Special case of self = 0" aNumber < 0 ifTrue: [^ (ZeroDivide dividend: self) signal] ifFalse: [^ self]]. ^ (aNumber * self ln) exp "Otherwise use logarithms"! Item was changed: ----- Method: Number>>sqrt (in category 'mathematical functions') ----- sqrt "Answer the square root of the receiver." + self subclassResponsibility! - ^self asFloat sqrt! Item was added: + ----- Method: SmallInteger>>sqrt (in category 'mathematical functions') ----- + sqrt + self negative ifTrue: [ + ^ DomainError signal: 'sqrt undefined for number less than zero.' ]. + ^super sqrt!

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Spreadsheet morph
by Chris Cunnington 14 Oct '11

14 Oct '11

In unrelated exploring I found your spreadsheet. download this: http://www.opencroquet.org/ and execute: SpreadSheet new openInWorld Chris

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Re: [squeak-dev] Spreadsheet morph
by Gary Dunn 14 Oct '11

14 Oct '11

Your suggestions are spot on. I was thinking there might be a squeak way of doing this lurking just out of sight. Same as I discovered that a thoughtful collection of morphs will do what I thought would require massive programming. Last weekend I played with table layout in a text morph, trying to understand what all those options do ... alignment, spacing, etc. I did not get very far. Next time I will try a PasteUpMorph and hopefully I'll get father. I do not think it wise to recreate Excel in smalltalk. Better to have a smalltalk object that does spreadsheet kinds of things in a smalltalk way. Gary Dunn Open Slate Project http://openslate.org On Oct 11, 2011 9:10 PM, "Stéphane Rollandin" <lecteur(a)zogotounga.net> wrote: Ok, never mind, I was just giving some pointers. Sorry if they are not useful. Stef

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Re: [vwnc] Any serializer can customize serialization strategy?
by Hernán Morales Durand 14 Oct '11

14 Oct '11

Hi Paul, Thanks for your detailed reply. What you describe seems suitable for my needs (I'm interested in simplest techniques, my problem is complex enough to try premature improvements at the tool level :) however I cannot comment more until I do some real experiments with SRP. Thanks again Hernán 2011/10/12 Paul Baumann <paul.baumann(a)theice.com>: > Hernán, > > There are several ways to do it with SRP. > > The encoding supports embedded data (variable and fixed width), so you could do inline serialization. It is clever enough that it is even possible to do this with positional access even to base64 encoded data. Tricks like that are used for example to update individual values in a persistent index. There are simpler techniques that should work for any marshaler... > > All marshalers should have some form of pre-save and post-load exchange. SRP has many ways to pre-save and post-load while maintaining relative references. SRP can even do post-load exchanges after the rest of the object graph is loaded and still keep relative references (without using a #become:). > > Save a proxy in place of the object. The proxy would be a class that you create to do what you want as a post-load actions. You can create the proxy as part of a pre-save action. The proxy can have the encoded binary ByteArray you want embedded in the data. The post-load of the proxy would typically unmarshal the embedded data. Here is an example of a class-based exchange: > > SpecialSaveObject>>srpSavePreMap: aContext > ^MyOtherMarshalProxy newFor: self > > MyOtherMarshalerProxy.binData > > MyOtherMarshalerProxy class>>newFor: anObject > ^self new save: anObject > > MyOtherMarshalProxy>>save: anObject > binData := self marshaler saveAsBinary: anObject. > > MyOtherMarshalerProxy>>srpLoadPostMap: aContext > ^OtherMarshaler loadFromBinary: binData > > Depending on your needs, you might want your object to remember the embedded data. In that case, you could store the encoded data in an inst var that is lazy-initialized as a pre-save action and save only that inst var. A post-load action could perhaps read the other attributes from the encoded data that you saved. > > SRP also allows any object to answer back "extended attributes" that are saved with an object (#srpExtendedAttributes) and can be restored after loading (#srpExtendedAttributes:). Extended attributes are typically data you want associated with an object that is not directly referenced by the object. You could save/load encoded data along with the SRP saved object. > > Paul Baumann > > > > -----Original Message----- > From: vwnc-bounces(a)cs.uiuc.edu [mailto:vwnc-bounces@cs.uiuc.edu] On Behalf Of Hernán Morales Durand > Sent: Monday, October 10, 2011 15:36 > To: Pharo Development; The general-purpose Squeak developers list; vwnc mailing list > Subject: [vwnc] Any serializer can customize serialization strategy? > > Is there any serializer (Fuel/StOMP/Ma object > serialization/BOSS/SRP/SIXX??) which let me attach an external > compressor/decompressor for specific Strings to the > serialization/deserialization process? With external I mean it could > be in a separate binary (I could arrange the binding though). > Thanks > > Hernán > > _______________________________________________ > vwnc mailing list > vwnc(a)cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/vwnc > > This message may contain confidential information and is intended for specific recipients unless explicitly noted otherwise. If you have reason to believe you are not an intended recipient of this message, please delete it and notify the sender. This message may not represent the opinion of IntercontinentalExchange, Inc. (ICE), its subsidiaries or affiliates, and does not constitute a contract or guarantee. Unencrypted electronic mail is not secure and the recipient of this message is expected to provide safeguards from viruses and pursue alternate means of communication where privacy or a binding message is desired. >

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Daily Commit Log
by commits＠source.squeak.org 14 Oct '11

14 Oct '11

Changes to Trunk (http://source.squeak.org/trunk.html) in the last 24 hours: http://lists.squeakfoundation.org/pipermail/packages/2011-October/005025.ht… Name: Kernel-nice.634 Ancestors: Kernel-eem.633 Move Complex conversion (#asComplex #adaptToComplex:andSend:) one level upper in Number. Use squared where possible in Complex. =============================================

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The Trunk: Kernel-nice.634.mcz
by commits＠source.squeak.org 14 Oct '11

14 Oct '11

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.634.mcz ==================== Summary ==================== Name: Kernel-nice.634 Author: nice Time: 14 October 2011, 12:34:15.894 am UUID: ec28e2e7-ee3e-41a9-9eed-dd75acc1a7cf Ancestors: Kernel-eem.633 Move Complex conversion (#asComplex #adaptToComplex:andSend:) one level upper in Number. Use squared where possible in Complex. =============== Diff against Kernel-eem.633 =============== Item was changed: ----- Method: Complex>>raisedToInteger: (in category 'mathematical functions') ----- raisedToInteger: operand "Answer the receiver raised to the power operand, an Integer." "implementation note: this code is copied from Number. This suggest that both Number and Complex should have an ArithmeticValue common superclass like in Visualworks. Or maybe should it be a Traits (a property of fields ?)" | count result | operand isInteger ifFalse: [^ ArithmeticError signal: 'parameter is not an Integer']. operand = 0 ifTrue: [^ self class one]. operand = 1 ifTrue: [^ self]. operand < 0 ifTrue: [^ (self raisedToInteger: operand negated) reciprocal]. count := 1 bitShift: (operand-1) highBit. result := self class one. [count > 0] whileTrue: + [result := result squared. - [result := result * result. (operand bitAnd: count) = 0 ifFalse: [result := result * self]. count := count bitShift: -1]. ^ result! Item was removed: - ----- Method: Float>>adaptToComplex:andSend: (in category 'converting') ----- - adaptToComplex: rcvr andSend: selector - "If I am involved in arithmetic with a Complex number, convert me to a Complex number." - ^ rcvr perform: selector with: self asComplex! Item was removed: - ----- Method: Float>>asComplex (in category 'converting') ----- - asComplex - "Answer a Complex number that represents value of the the receiver." - - ^ Complex real: self imaginary: 0! Item was removed: - ----- Method: Fraction>>adaptToComplex:andSend: (in category 'converting') ----- - adaptToComplex: rcvr andSend: selector - "If I am involved in arithmetic with a Complex number, convert me to a Complex number." - ^ rcvr perform: selector with: self asComplex! Item was removed: - ----- Method: Fraction>>asComplex (in category 'converting') ----- - asComplex - "Answer a Complex number that represents value of the the receiver." - - ^ Complex real: self imaginary: 0! Item was removed: - ----- Method: Integer>>adaptToComplex:andSend: (in category 'converting') ----- - adaptToComplex: rcvr andSend: selector - "If I am involved in arithmetic with a Complex number, convert me to a Complex number." - ^ rcvr perform: selector with: self asComplex! Item was removed: - ----- Method: Integer>>asComplex (in category 'converting') ----- - asComplex - "Answer a Complex number that represents value of the the receiver." - - ^ Complex real: self imaginary: 0! Item was added: + ----- Method: Number>>adaptToComplex:andSend: (in category 'converting') ----- + adaptToComplex: rcvr andSend: selector + "If I am involved in arithmetic with a Complex number, convert me to a Complex number." + ^ rcvr perform: selector with: self asComplex! Item was added: + ----- Method: Number>>asComplex (in category 'converting') ----- + asComplex + "Answer a Complex number that represents value of the the receiver." + + ^ Complex real: self imaginary: 0!

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Re: Migrating Complex in a separate package
by Rodney Polkinghorne 14 Oct '11

14 Oct '11

> How many of you use Complex ? I do. > Facts: > - Complex is present in Squeak trunk image but not used in Kernel > - Complex is absent from Pharo image. extra fact: - Complex is absent from Cuis I think a common Complex library makes sense. > What do you think of these proposals ? If complex numbers are removed from the image, there's a risk that scientists evaluating Squeak won't find them, and will reject Smalltalk as a result. Complex can't be a library, because it takes special syntax to parse 3+4i. Or so everyone thinks, who hasn't seen Smalltalk. I think brevity trumps the arguments for ComplexNumber. Rebuttal: 1. Does any other language call them that? Scheme, C, Python and Haskell all say complex. 2. Smalltalk has been used for 30 years. Has there ever been an isComplex method that didn't refer to numbers? 3. All symbolic algebra systems I know about define isKnown, to test for literal values of any type. Users can define isKnownComplex as self isKnown & self isComplex if they want to. > unifying Complex and Point I think points with non-elemental arithmetic would be too big a change. However, Point>>asArgandComplex and Complex>>asArgandPoint would be useful. Rodney

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new Cog VMs available...
by Eliot Miranda 13 Oct '11

13 Oct '11

...in http://www.mirandabanda.org/files/Cog/VM/VM.r2495/. These fix the regression introduced in r2487 in introducing faster MNu processing. The bug was the leaking up of an error code that was misinterpreted as a valid target machine code method. Thanks /very/ much to those of you who tested the 2493 & 2494 VMs. With your help this bug was found quickly. I now have reason to hope that these VMs will be quite stable. Here's the readme: CogVM binaries as per VMMaker.oscog-eem.127/r2495. Fix MNU PIC creation not to answer an error code to the interpreter. This is the call 0x00000013 bug. again thanks -- best, Eliot

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Re: [Pharo-project] About ~= and ~~
by Eliot Miranda 12 Oct '11

12 Oct '11

On Wed, Oct 12, 2011 at 8:38 AM, Levente Uzonyi <leves(a)elte.hu> wrote: > On Wed, 12 Oct 2011, Clara Allende wrote: > > Hi guys, >> >> I'm wondering, why? >> >> ProtoObject>> ~~ anObject >> "Answer whether the receiver and the argument are not the same object >> (do not have the same object pointer)." >> >> self == anObject >> ifTrue: [^ false] >> ifFalse: [^ true] >> >> Instead of: >> ProtoObject>> ~~ anObject >> "Answer whether the receiver and the argument are not the same object >> (do not have the same object pointer)." >> >> ^(self == anObject) not >> >> And why? >> Object >> ~= anObject >> "Answer whether the receiver and the argument do not represent the >> same object." >> >> ^self = anObject == false >> >> Instead of >> Object>> ~= anObject >> "Answer whether the receiver and the argument do not represent the >> same object." >> >> ^(self = anObject) not. >> >> Is there any particular reason for this that I'm missing? >> > > Performance. > But better still is to add a ~~ primitive. I did this for VisualWorks. e.g. primitive 150 is free. why don't we use that for 1.4/4.3? > > > Levente > > Thanks in advance! >> -- >> >> "*Most good programmers do programming not because they expect to get paid >> or get adulation by the public, but because it is fun to program.*" >> >> Linus Torvalds >> >> > -- best, Eliot

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Re: [squeak-dev] The Trunk: Tools-bf.383.mcz
by Frank Shearar 12 Oct '11

12 Oct '11

On 11 October 2011 15:11, <commits(a)source.squeak.org> wrote: > Bert Freudenberg uploaded a new version of Tools to project The Trunk: > http://source.squeak.org/trunk/Tools-bf.383.mcz > > ==================== Summary ==================== > > Name: Tools-bf.383 > Author: bf > Time: 11 October 2011, 4:11:42.987 pm > UUID: c27c59ef-77c3-46c3-b24a-b0034efcd457 > Ancestors: Tools-eem.382 > > VersionsBrowser: when reverting a method, put it in the previous category, too. > > =============== Diff against Tools-eem.382 =============== Nice! I ran into this the other day but wasn't online to report it, and then forgot to! It's a pity the original code uses "cat" and "category" as variable names. "oldCategory" might be a better name (for a separate commit)? frank

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