Squeak-dev October 2011

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160 discussions

Daily Commit Log
by commits＠source.squeak.org 01 Nov '11

01 Nov '11

Changes to Trunk (http://source.squeak.org/trunk.html) in the last 24 hours: http://lists.squeakfoundation.org/pipermail/packages/2011-October/005053.ht… Name: Morphic-ul.587 Ancestors: Morphic-cmm.586 - fix: avoid division by zero when searching in an empty PluggableListMorph =============================================

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The Trunk: Morphic-ul.587.mcz
by commits＠source.squeak.org 31 Oct '11

31 Oct '11

Levente Uzonyi uploaded a new version of Morphic to project The Trunk: http://source.squeak.org/trunk/Morphic-ul.587.mcz ==================== Summary ==================== Name: Morphic-ul.587 Author: ul Time: 31 October 2011, 5:23:54.884 pm UUID: 6086ce82-310b-b14e-8ccf-84c807d3bccd Ancestors: Morphic-cmm.586 - fix: avoid division by zero when searching in an empty PluggableListMorph =============== Diff against Morphic-cmm.586 =============== Item was changed: ----- Method: PluggableListMorph>>basicKeyPressed: (in category 'model access') ----- basicKeyPressed: aChar | milliseconds slowKeyStroke listSize newSelectionIndex oldSelectionIndex startIndex | oldSelectionIndex := newSelectionIndex := self getCurrentSelectionIndex. listSize := self getListSize. + listSize = 0 ifTrue: [ ^self flash ]. milliseconds := Time millisecondClockValue. slowKeyStroke := (Time milliseconds: milliseconds since: lastKeystrokeTime) > (self class filterableLists ifTrue: [500] ifFalse: [ 300 ]). lastKeystrokeTime := milliseconds. slowKeyStroke ifTrue: [ self class filterableLists ifTrue: [ self hasFilter ifFalse: [ priorSelection := self modelIndexFor: self selectionIndex] ]. "forget previous keystrokes and search in following elements" lastKeystrokes := aChar asLowercase asString. newSelectionIndex := newSelectionIndex \\ listSize + 1. self class filterableLists ifTrue: [ list := self getFullList ] ] ifFalse: [ "append quick keystrokes but don't move selection if it still matches" lastKeystrokes := lastKeystrokes , aChar asLowercase asString. newSelectionIndex := newSelectionIndex max: 1 ]. "No change if model is locked" model okToChange ifFalse: [ ^ self ]. self class filterableLists ifTrue: [ self filterList ; updateList. newSelectionIndex := self modelIndexFor: 1 ] ifFalse: [ startIndex := newSelectionIndex. listSize := self getListSize. [ (self getListItem: newSelectionIndex) asString withBlanksTrimmed asLowercase beginsWith: lastKeystrokes ] whileFalse: [ (newSelectionIndex := newSelectionIndex \\ listSize + 1) = startIndex ifTrue: [ ^ self flash"Not in list." ] ]. newSelectionIndex = oldSelectionIndex ifTrue: [ ^ self flash ] ]. (self hasFilter and: [(self getCurrentSelectionIndex = newSelectionIndex) not]) ifTrue: [self changeModelSelection: newSelectionIndex]!

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Daily Commit Log
by commits＠source.squeak.org 30 Oct '11

30 Oct '11

Changes to Trunk (http://source.squeak.org/trunk.html) in the last 24 hours: http://lists.squeakfoundation.org/pipermail/packages/2011-October/005049.ht… Name: KernelTests-nice.207 Ancestors: KernelTests-nice.206 Additional test from Juan for nthRoot: an Integer with inexact nthRoot could answer a better Float than infinity. ============================================= http://lists.squeakfoundation.org/pipermail/packages/2011-October/005050.ht… Name: Kernel-nice.645 Ancestors: Kernel-ael.643 Yet another version of #nthRoot: from Cuis 1) Receivers too big for Float arithmetic but without exact answer, and a better float than infinity is possible. 2) Besides, a small performance tweak: don't call 'selfAsFloat nthRoot: aPositiveInteger' if the result will be infinity, i.e. if the receiver is infinity. ============================================= http://lists.squeakfoundation.org/pipermail/packages/2011-October/005051.ht… Name: KernelTests-nice.208 Ancestors: KernelTests-nice.207 There might be a best inexact square root approximation than infinity to some LargePositiveInteger in the range (1<<54-1<<970 to: 1<<54-1<<1994) ============================================= http://lists.squeakfoundation.org/pipermail/packages/2011-October/005052.ht… Name: Kernel-nice.646 Ancestors: Kernel-nice.645 There might be a best inexact square root approximation than Float infinity to some LargePositiveInteger in the range (1<<54-1<<970 to: 1<<54-1<<1994) =============================================

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The Inbox: Collections-nice.464.mcz
by commits＠source.squeak.org 29 Oct '11

29 Oct '11

Nicolas Cellier uploaded a new version of Collections to project The Inbox: http://source.squeak.org/inbox/Collections-nice.464.mcz ==================== Summary ==================== Name: Collections-nice.464 Author: nice Time: 29 October 2011, 10:54:15.683 pm UUID: 1a03ae5c-e979-4e30-b808-e7a26fcf4e97 Ancestors: Collections-ul.463 Optimize RunArray. This should not be noticeable for Text, but as a general library, it's important for any other potential use. Also move it off ArrayedCollection which serves nothing to such subclass. =============== Diff against Collections-ul.463 =============== Item was changed: + SequenceableCollection subclass: #RunArray - ArrayedCollection subclass: #RunArray instanceVariableNames: 'runs values lastIndex lastRun lastOffset' classVariableNames: '' poolDictionaries: '' category: 'Collections-Arrayed'! !RunArray commentStamp: '<historical>' prior: 0! My instances provide space-efficient storage of data which tends to be constant over long runs of the possible indices. Essentially repeated values are stored singly and then associated with a "run" length that denotes the number of consecutive occurrences of the value. My two important variables are runs An array of how many elements are in each run values An array of what the value is over those elements The variables lastIndex, lastRun and lastOffset cache the last access so that streaming through RunArrays is not an N-squared process. Many complexities of access can be bypassed by using the method RunArray withStartStopAndValueDo:! Item was changed: ----- Method: RunArray class>>newFrom: (in category 'instance creation') ----- newFrom: aCollection "Answer an instance of me containing the same elements as aCollection." + | runs values lastRun lastValue | + runs := (Array new: aCollection size // 2) writeStream. + values := (Array new: aCollection size // 2) writeStream. + lastRun := 0. + lastValue := Object new. + aCollection do: [:x | + lastValue = x + ifTrue: [lastRun := lastRun + 1] + ifFalse: + [lastRun > 0 + ifTrue: + [runs nextPut: lastRun. + values nextPut: lastValue]. + lastRun := 1. + lastValue := x]]. + lastRun > 0 + ifTrue: + [runs nextPut: lastRun. + values nextPut: lastValue]. + ^self basicNew setRuns: runs contents setValues: values contents - | newCollection | - newCollection := self new. - aCollection do: [:x | newCollection addLast: x]. - ^newCollection " RunArray newFrom: {1. 2. 2. 3} {1. $a. $a. 3} as: RunArray ({1. $a. $a. 3} as: RunArray) values "! Item was changed: + ----- Method: RunArray>>= (in category 'comparing') ----- - ----- Method: RunArray>>= (in category 'accessing') ----- = otherArray "Test if all my elements are equal to those of otherArray" + self == otherArray ifTrue: [^true]. + self species == otherArray species ifFalse: [^ false]. (otherArray isMemberOf: RunArray) ifFalse: [^ self hasEqualElements: otherArray]. "Faster test between two RunArrays" ^ (runs hasEqualElements: otherArray runs) and: [values hasEqualElements: otherArray values]! Item was added: + ----- Method: RunArray>>add:withOccurrences: (in category 'adding') ----- + add: newObject withOccurrences: anInteger + "Add value as the last element of the receiver, the given number of times" + anInteger <= 0 ifTrue: [ ^self ]. + lastIndex := nil. "flush access cache" + (runs size=0 or: [values last ~= newObject]) + ifTrue: + [runs := runs copyWith: anInteger. + values := values copyWith: newObject] + ifFalse: + [runs at: runs size put: runs last + anInteger]! Item was changed: ----- Method: RunArray>>addLast:times: (in category 'adding') ----- addLast: value times: times "Add value as the last element of the receiver, the given number of times" + self deprecated: 'use add:withOccurrences:'. + ^self add: value withOccurrences: times! - times = 0 ifTrue: [ ^self ]. - lastIndex := nil. "flush access cache" - (runs size=0 or: [values last ~= value]) - ifTrue: - [runs := runs copyWith: times. - values := values copyWith: value] - ifFalse: - [runs at: runs size put: runs last+times]! Item was added: + ----- Method: RunArray>>allSatisfy: (in category 'enumerating') ----- + allSatisfy: aBlock + "Only evaluate once per run" + + ^values allSatisfy: aBlock! Item was added: + ----- Method: RunArray>>anySatisfy: (in category 'enumerating') ----- + anySatisfy: aBlock + "Only evaluate once per run" + + ^values anySatisfy: aBlock! Item was added: + ----- Method: RunArray>>asBag (in category 'converting') ----- + asBag + | aBag | + aBag := Bag new: values size. + self runsAndValuesDo: [:run :value | + aBag add: value withOccurrences: run]. + ^aBag! Item was added: + ----- Method: RunArray>>asSet (in category 'converting') ----- + asSet + ^values asSet! Item was added: + ----- Method: RunArray>>collect: (in category 'enumerating') ----- + collect: aBlock + "Beware, the block will be evaluated only once per group of values." + ^(self class runs: runs copy contents values: (values collect: aBlock)) coalesce! Item was added: + ----- Method: RunArray>>copyUpThrough: (in category 'copying') ----- + copyUpThrough: anElement + "Optimized" + + | newValues | + newValues := values copyUpThrough: anElement. + ^ self class + runs: (runs copyFrom: 1 to: newValues size) + values: newValues! Item was added: + ----- Method: RunArray>>copyUpTo: (in category 'copying') ----- + copyUpTo: anElement + "Optimized" + + | newValues | + newValues := values copyUpTo: anElement. + ^ self class + runs: (runs copyFrom: 1 to: newValues size) + values: newValues! Item was added: + ----- Method: RunArray>>copyUpToLast: (in category 'copying') ----- + copyUpToLast: anElement + "Optimized" + + | newValues | + newValues := values copyUpToLast: anElement. + ^ self class + runs: (runs copyFrom: 1 to: newValues size) + values: newValues! Item was added: + ----- Method: RunArray>>count: (in category 'enumerating') ----- + count: aBlock + "Beware, the block will be evaluated only once per group of values." + | count | + count := 0. + self runsAndValuesDo: [:run :value | + (aBlock value: value) + ifTrue: + [count := count + run]]. + ^count! Item was added: + ----- Method: RunArray>>detect:ifNone: (in category 'enumerating') ----- + detect: aBlock ifNone: exceptionBlock + "Only evaluate once per run" + + ^values detect: aBlock ifNone: exceptionBlock ! Item was added: + ----- Method: RunArray>>detectMax: (in category 'enumerating') ----- + detectMax: aBlock + "Only evaluate once per run" + + ^values detectMax: aBlock! Item was added: + ----- Method: RunArray>>detectMin: (in category 'enumerating') ----- + detectMin: aBlock + "Only evaluate once per run" + + ^values detectMin: aBlock! Item was added: + ----- Method: RunArray>>detectSum: (in category 'enumerating') ----- + detectSum: aBlock + "Only loop on runs" + | sum | + sum := 0. + self runsAndValuesDo: [:run :value | + sum := (aBlock value: value) * run + sum]. + ^ sum! Item was added: + ----- Method: RunArray>>do: (in category 'enumerating') ----- + do: aBlock + "This is refined for speed" + + 1 to: runs size do: [:i | + | r v | + v := values at: i. + r := runs at: i. + [( r := r - 1) >= 0] + whileTrue: [aBlock value: v]].! Item was added: + ----- Method: RunArray>>fillFrom:with: (in category 'private') ----- + fillFrom: aCollection with: aBlock + "Evaluate aBlock with each of aCollections's elements as the argument. + Collect the resulting values into self. Answer self." + + | newRuns newValues lastLength lastValue | + newRuns := (Array new: aCollection size) writeStream. + newValues := (Array new: aCollection size) writeStream. + lastLength := 0. + lastValue := Object new. + aCollection do: [:each | + | value | + value := aBlock value: each. + lastValue = value + ifTrue: [lastLength := lastLength + 1] + ifFalse: + [lastLength > 0 + ifTrue: + [newRuns nextPut: lastLength. + newValues nextPut: lastValue]. + lastLength := 1. + lastValue := value]]. + lastLength > 0 + ifTrue: + [newRuns nextPut: lastLength. + newValues nextPut: lastValue]. + self setRuns: newRuns contents setValues: newValues contents! Item was added: + ----- Method: RunArray>>findFirst: (in category 'enumerating') ----- + findFirst: aBlock + | index | + index := 1. + self runsAndValuesDo: [ :run :value | + (aBlock value: value) ifTrue: [^index]. + index := index + run]. + ^0! Item was added: + ----- Method: RunArray>>findLast: (in category 'enumerating') ----- + findLast: aBlock + | index | + index := values size + 1. + [(index := index - 1) >= 1] whileTrue: + [(aBlock value: (values at: index)) ifTrue: [^(1 to: index) detectSum: [:i | runs at: i]]]. + ^0! Item was added: + ----- Method: RunArray>>includes: (in category 'testing') ----- + includes: anObject + "Answer whether anObject is one of the receiver's elements." + + ^values includes: anObject! Item was added: + ----- Method: RunArray>>isSorted (in category 'testing') ----- + isSorted + ^values isSorted! Item was added: + ----- Method: RunArray>>isSortedBy: (in category 'testing') ----- + isSortedBy: aBlock + ^values isSortedBy: aBlock! Item was added: + ----- Method: RunArray>>noneSatisfy: (in category 'enumerating') ----- + noneSatisfy: aBlock + "Only evaluate once per run" + + ^values noneSatisfy: aBlock! Item was added: + ----- Method: RunArray>>remove:ifAbsent: (in category 'removing') ----- + remove: anObject ifAbsent: exceptionBlock + | index mustCoalesce run | + index := values indexOf: anObject ifAbsent: [^exceptionBlock value]. + (run := runs at: index) > 1 + ifTrue: [runs at: index put: run - 1] + ifFalse: + [mustCoalesce := index > 1 and: [index < values size and: [(values at: index - 1) = (values at: index + 1)]]. + runs := runs copyWithoutIndex: index. + values := values copyWithoutIndex: index. + mustCoalesce + ifTrue: + [runs at: index - 1 put: (runs at: index - 1) + (runs at: index). + runs := runs copyWithoutIndex: index. + values := values copyWithoutIndex: index]]. + ^anObject! Item was added: + ----- Method: RunArray>>removeAll (in category 'removing') ----- + removeAll + runs := Array new. + values := Array new! Item was added: + ----- Method: RunArray>>replace: (in category 'enumerating') ----- + replace: aBlock + "Beware, the block will be evaluated only once per group of values." + values := values replace: aBlock. + self coalesce! Item was added: + ----- Method: RunArray>>reverseDo: (in category 'enumerating') ----- + reverseDo: aBlock + "This is refined for speed" + + | i | + i := runs size. + [i > 0] + whileTrue: + [ | r v | + v := values at: i. + r := runs at: i. + i := i - 1. + [( r := r - 1) >= 0] + whileTrue: [aBlock value: v]].! Item was added: + ----- Method: RunArray>>select: (in category 'enumerating') ----- + select: aBlock + "Beware, the block will be evaluated only once per group of values." + | newRuns newValues | + newRuns := (Array new: runs size) writeStream. + newValues := (Array new: values size) writeStream. + self runsAndValuesDo: [:run :value | + (aBlock value: value) + ifTrue: + [newRuns add: run. + newValues add: value]]. + ^(self class runs: newRuns contents values: newValues contents) coalesce!

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Smalltalk Job in L.A.
by blake 29 Oct '11

29 Oct '11

Hey, guys-- There's a job opening with Sempra, some kind of energy company, in the Los Angeles area (Marina Del Rey, Monterey Park--you can Google the locations), that requires C++ and Smalltalk. ===Blake===

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Re: [squeak-dev] The Trunk: Kernel-nice.646.mcz
by Nicolas Cellier 29 Oct '11

29 Oct '11

2011/10/29 <commits(a)source.squeak.org>: > Nicolas Cellier uploaded a new version of Kernel to project The Trunk: > http://source.squeak.org/trunk/Kernel-nice.646.mcz > > ==================== Summary ==================== > > Name: Kernel-nice.646 > Author: nice > Time: 29 October 2011, 3:25:43.994 pm > UUID: cd46101c-40a4-49fd-b358-a8d0c555810f > Ancestors: Kernel-nice.645 > > There might be a best inexact square root approximation than Float infinity to some LargePositiveInteger in the range (1<<54-1<<970 to: 1<<54-1<<1994) > I mean a better approximation... But it should effectively be the best. > =============== Diff against Kernel-nice.645 =============== > > Item was changed: > ----- 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 squared = self ifTrue: [ > + ^guess ]. > + > + "Nothing else can be done. No exact answer means answer must be a Float. > + Answer the best we have which is the rounded sqrt." > + guess := (self * 4) sqrtFloor. > + ^(guess // 2 + (guess \\ 2)) asFloat]. > - ^guess ]]. > > "We need an approximate result" > ^floatResult! > > Item was changed: > ----- 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." > + | selfAsFloat | > + self mightBeASquare > + ifFalse: > + [selfAsFloat := self asFloat. > + selfAsFloat isFinite ifTrue: [^self asFloat sqrt ]]. > - self mightBeASquare ifFalse: [ > - ^self asFloat sqrt ]. > > + "If some exact solution might exist, or self asFloat isInfinite, call potentially expensive super" > - "If some exact solution might exist, call potentially expensive super" > ^super sqrt! > > >

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The Trunk: Kernel-nice.646.mcz
by commits＠source.squeak.org 29 Oct '11

29 Oct '11

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.646.mcz ==================== Summary ==================== Name: Kernel-nice.646 Author: nice Time: 29 October 2011, 3:25:43.994 pm UUID: cd46101c-40a4-49fd-b358-a8d0c555810f Ancestors: Kernel-nice.645 There might be a best inexact square root approximation than Float infinity to some LargePositiveInteger in the range (1<<54-1<<970 to: 1<<54-1<<1994) =============== Diff against Kernel-nice.645 =============== Item was changed: ----- 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 squared = self ifTrue: [ + ^guess ]. + + "Nothing else can be done. No exact answer means answer must be a Float. + Answer the best we have which is the rounded sqrt." + guess := (self * 4) sqrtFloor. + ^(guess // 2 + (guess \\ 2)) asFloat]. - ^guess ]]. "We need an approximate result" ^floatResult! Item was changed: ----- 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." + | selfAsFloat | + self mightBeASquare + ifFalse: + [selfAsFloat := self asFloat. + selfAsFloat isFinite ifTrue: [^self asFloat sqrt ]]. - self mightBeASquare ifFalse: [ - ^self asFloat sqrt ]. + "If some exact solution might exist, or self asFloat isInfinite, call potentially expensive super" - "If some exact solution might exist, call potentially expensive super" ^super sqrt!

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The Trunk: KernelTests-nice.208.mcz
by commits＠source.squeak.org 29 Oct '11

29 Oct '11

Nicolas Cellier uploaded a new version of KernelTests to project The Trunk: http://source.squeak.org/trunk/KernelTests-nice.208.mcz ==================== Summary ==================== Name: KernelTests-nice.208 Author: nice Time: 29 October 2011, 3:24:06.652 pm UUID: 98713787-6ba4-424d-b622-0c1f459ac49c Ancestors: KernelTests-nice.207 There might be a best inexact square root approximation than infinity to some LargePositiveInteger in the range (1<<54-1<<970 to: 1<<54-1<<1994) =============== Diff against KernelTests-nice.207 =============== Item was added: + ----- Method: IntegerTest>>testBigReceiverInexactSqrt (in category 'tests - mathematical functions') ----- + testBigReceiverInexactSqrt + " + IntegerTest new testBigReceiverInexactSqrt + " + + "Inexact 3rd root (not a whole cube number), so a Float must be answered. + However, receiver is too big for Float arithmethic." + | bigNum result | + bigNum := 100 factorial squared + 1. "Add 1 so it is not a whole square" + self assert: bigNum asFloat isInfinite. "Otherwise, we chose a bad sample" + result := bigNum sqrt. + self assert: result class == Float. + self deny: result isInfinite. + self assert: result = 100 factorial asFloat. "No other float is closer. See following lines" + self assert: (result successor asFraction squared - bigNum) abs >= (result asFraction squared - bigNum) abs. + self assert: (result predecessor asFraction squared - bigNum) abs >= (result asFraction squared - bigNum) abs.!

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The Trunk: Kernel-nice.645.mcz
by commits＠source.squeak.org 29 Oct '11

29 Oct '11

Nicolas Cellier uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-nice.645.mcz ==================== Summary ==================== Name: Kernel-nice.645 Author: nice Time: 29 October 2011, 11:42:54.825 am UUID: 6c7fe149-d362-481d-803f-eecbec00619c Ancestors: Kernel-ael.643 Yet another version of #nthRoot: from Cuis 1) Receivers too big for Float arithmetic but without exact answer, and a better float than infinity is possible. 2) Besides, a small performance tweak: don't call 'selfAsFloat nthRoot: aPositiveInteger' if the result will be infinity, i.e. if the receiver is infinity. =============== Diff against Kernel-ael.643 =============== Item was changed: ----- Method: Integer>>nthRoot: (in category 'mathematical functions') ----- nthRoot: aPositiveInteger + "Answer the nth root of the receiver. + See #nthRootAlt: for an alternative implementation." - "Answer the nth root of the receiver." + | selfAsFloat floatResult guess delta higher lower raised | - | selfAsFloat floatResult guess raised higher lower delta | selfAsFloat := self asFloat. - floatResult := selfAsFloat nthRoot: aPositiveInteger. + "If we can't do Float arithmetic because we are too big, then look for an exact answer in exact arithmetic" + selfAsFloat isInfinite ifTrue: [ - "If we can't do Float arithmetic, then look for an exact answer in exact arithmetic" - floatResult isInfinite ifTrue: [ guess := self nthRootTruncated: aPositiveInteger. + (guess raisedToInteger: aPositiveInteger) = self + ifTrue: [ ^ guess ]. + "Nothing else can be done. No exact answer means answer must be a Float. + Answer the best we have." + ^guess asFloat ]. - (guess raisedToInteger: aPositiveInteger) = self ifTrue: [^guess]. - ^floatResult ]. + floatResult := selfAsFloat nthRoot: aPositiveInteger. 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 1(jmv): This algorithm is faster than #nthRootTruncated: for big n (aPositiveInteger) + but fails if self asFloat isInfinite. + Note 2(jmv): The algorithms I found for computing the nthRoot would havily use - 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!

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The Trunk: KernelTests-nice.207.mcz
by commits＠source.squeak.org 29 Oct '11

29 Oct '11

Nicolas Cellier uploaded a new version of KernelTests to project The Trunk: http://source.squeak.org/trunk/KernelTests-nice.207.mcz ==================== Summary ==================== Name: KernelTests-nice.207 Author: nice Time: 29 October 2011, 11:39:06.749 am UUID: ef2c95d0-2f77-47da-b2de-f232b4043dec Ancestors: KernelTests-nice.206 Additional test from Juan for nthRoot: an Integer with inexact nthRoot could answer a better Float than infinity. =============== Diff against KernelTests-nice.206 =============== Item was added: + ----- Method: IntegerTest>>testBigReceiverInexactNthRoot (in category 'tests - mathematical functions') ----- + testBigReceiverInexactNthRoot + " + IntegerTest new testBigReceiverInexactNthRoot + " + + "Inexact 3rd root (not a whole cube number), so a Float must be answered. + However, receiver is too big for Float arithmethic." + | bigNum result | + bigNum := (100 factorial raisedTo: 3) + 1. "Add 1 so it is not a whole cube" + self assert: bigNum asFloat isInfinite. "Otherwise, we chose a bad sample" + result := bigNum nthRoot: 3. + self assert: result class == Float. + self deny: result isInfinite. + self assert: result = 100 factorial asFloat. "No other float is closer. See following line" + self assert: 100 factorial asFloat = (100 factorial+1) asFloat!

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