diff -r 5c6890f8da89 -r 1cbf4cdfc288 Integer.st
--- a/Integer.st	Sat Aug 14 12:56:21 2010 +0200
+++ b/Integer.st	Tue Aug 17 17:27:46 2010 +0200
@@ -1139,6 +1139,7 @@
     ^ self == Integer
 ! !
 
+
 !Integer methodsFor:'Compatibility-Dolphin'!
 
 & aNumber
@@ -3059,18 +3060,17 @@
 primeFactors
     "return a collection of prime factors of the receiver.
      For prime numbers, an empty collection is returned.
-     Can take a long time for big numbers
-     (win a nobel price, if you find something quick)"
+     Can take a long time for big numbers"
 
     ^ self primeFactorsUpTo:nil
 
     "
      2 to:10000 do:[:n |
-	self assert:((n isPrime and:[ n primeFactors isEmpty])
-		    or:[ n isPrime not and:[n primeFactors product = n]])
+        self assert:((n isPrime and:[ n primeFactors isEmpty])
+                    or:[ n isPrime not and:[n primeFactors product = n]])
      ]
      3 to:10000 do:[:n |
-	self assert:(n factorial primeFactors product = n factorial)
+        self assert:(n factorial primeFactors product = n factorial)
      ]
 
      13195 primeFactors
@@ -3091,18 +3091,22 @@
      1000000000 primeFactors
 
      Time millisecondsToRun:[
-	1000 timesRepeat:[
-	    10000000000000000000000000000000000000 primeFactors
-	]
+        1000 timesRepeat:[
+            10000000000000000000000000000000000000 primeFactors
+        ]
      ]   421
     "
+
+    "Modified: / 17-08-2010 / 17:27:33 / cg"
 !
 
 primeFactorsUpTo:limitArgOrNil
     "return a collection of prime factors of the receiver.
      For prime numbers, an empty collection is returned.
      Can take a long time for big numbers
-     (win a nobel price, if you find something quick)"
+     (win a nobel price, if you find something quick (*)
+
+     (*):which does not mean that the code below is optimal - far from it !!"
 
     |rest n factors limit lastPrime checkThisFactor nextTry|
 
@@ -3110,34 +3114,34 @@
     rest := self.
     limit := (rest // 2).
     limitArgOrNil notNil ifTrue:[
-	limit := limit min:limitArgOrNil.
+        limit := limit min:limitArgOrNil.
     ].
 
     "/ try to get the number down fast:
     n := rest lowBit.
     n ~~ 1 ifTrue:[
-	self == 2 ifTrue:[^ #() ].
-	factors add:2 withOccurrences:(n-1).
-	rest := rest rightShift:(n-1).
+        self == 2 ifTrue:[^ #() ].
+        factors add:2 withOccurrences:(n-1).
+        rest := rest rightShift:(n-1).
     ].
 
     checkThisFactor := [:prime |
-	    prime*prime > rest ifTrue:[
-		(rest ~~ 1 and:[factors notEmpty]) ifTrue:[ factors add:rest ].
-		^ factors.
-	    ].
-
-	    [rest \\ prime == 0] whileTrue:[
-		factors add:prime.
-		rest := rest // prime.
-		rest == 1 ifTrue:[^ factors].
-	    ].
-	    lastPrime := prime.
-	].
+            prime*prime > rest ifTrue:[
+                (rest ~~ 1 and:[factors notEmpty]) ifTrue:[ factors add:rest ].
+                ^ factors.
+            ].
+
+            [rest \\ prime == 0] whileTrue:[
+                factors add:prime.
+                rest := rest // prime.
+                rest == 1 ifTrue:[^ factors].
+            ].
+            lastPrime := prime.
+        ].
 
     limit <= 2000 ifTrue:[
-	Integer primesUpTo2000 do:checkThisFactor.
-	^ factors
+        Integer primesUpTo2000 do:checkThisFactor.
+        ^ factors
     ].
 
     "/ actually, all of the code is duplicated; once for primes from a table,
@@ -3150,37 +3154,37 @@
 
     nextTry := lastPrime + 2.
     [ nextTry <= limit ] whileTrue:[
-	"/ now, we are beyond the list of pre-generated primes.
-	"/ change our strategy to: see if it divides an odd number;
-	"/ if so, add the divisor's prime factors.
-	nextTry*nextTry > rest ifTrue:[
-	    (rest ~~ 1 and:[factors notEmpty]) ifTrue:[ factors add:rest ].
-	    ^ factors.
-	].
-	[(rest \\ nextTry) == 0] whileTrue:[
-	    "/ can only happen relatively late after the last prime,
-	    "/ because otherwise, the primeFactors of nextTry would already have
-	    "/ been found as divisors.
-	    "/ first chance is: (lastPrime + 2) squared
-	    nextTry < lastPrime squared ifTrue:[
-		"/ nextTry is a prime !!
-		factors add:nextTry
-	    ] ifFalse:[
-		factors addAll:(nextTry primeFactors).
-	    ].
-	    rest := rest // nextTry.
-	].
-	nextTry := nextTry + 2.
+        "/ now, we are beyond the list of pre-generated primes.
+        "/ change our strategy to: see if it divides an odd number;
+        "/ if so, add the divisor's prime factors.
+        nextTry*nextTry > rest ifTrue:[
+            (rest ~~ 1 and:[factors notEmpty]) ifTrue:[ factors add:rest ].
+            ^ factors.
+        ].
+        [(rest \\ nextTry) == 0] whileTrue:[
+            "/ can only happen relatively late after the last prime,
+            "/ because otherwise, the primeFactors of nextTry would already have
+            "/ been found as divisors.
+            "/ first chance is: (lastPrime + 2) squared
+            nextTry < lastPrime squared ifTrue:[
+                "/ nextTry is a prime !!
+                factors add:nextTry
+            ] ifFalse:[
+                factors addAll:(nextTry primeFactors).
+            ].
+            rest := rest // nextTry.
+        ].
+        nextTry := nextTry + 2.
     ].
     ^ factors
 
     "
      2 to:10000 do:[:n |
-	self assert:((n isPrime and:[ n primeFactors isEmpty])
-		    or:[ n isPrime not and:[n primeFactors product = n]])
+        self assert:((n isPrime and:[ n primeFactors isEmpty])
+                    or:[ n isPrime not and:[n primeFactors product = n]])
      ]
      3 to:10000 do:[:n |
-	self assert:(n factorial primeFactors product = n factorial)
+        self assert:(n factorial primeFactors product = n factorial)
      ]
 
      13195 primeFactors
@@ -3201,11 +3205,13 @@
      1000000000 primeFactors
 
      Time millisecondsToRun:[
-	1000 timesRepeat:[
-	    10000000000000000000000000000000000000 primeFactors
-	]
+        1000 timesRepeat:[
+            10000000000000000000000000000000000000 primeFactors
+        ]
      ]   421
     "
+
+    "Modified: / 17-08-2010 / 17:27:24 / cg"
 !
 
 raisedTo:exp mod:mod
@@ -3929,6 +3935,7 @@
     "Modified: 15.10.1997 / 18:43:49 / cg"
 ! !
 
+
 !Integer methodsFor:'special access'!
 
 exponent
@@ -4707,11 +4714,11 @@
 !Integer class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Integer.st,v 1.248 2010-08-02 10:34:20 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Integer.st,v 1.249 2010-08-17 15:27:46 cg Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic/Integer.st,v 1.248 2010-08-02 10:34:20 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Integer.st,v 1.249 2010-08-17 15:27:46 cg Exp $'
 ! !
 
 Integer initialize!