[Pkg] The Trunk: Kernel-ul.606.mcz

[commits at source.squeak.org]

Levente Uzonyi uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-ul.606.mcz

==================== Summary ====================

Name: Kernel-ul.606
Author: ul
Time: 18 July 2011, 5:26:44.832 pm
UUID: 765d93ce-2226-a942-abee-bd2f45d192f6
Ancestors: Kernel-nice.605

Copy the lowBit per byte table from SmallInteger >> #lowBit to a class variable in Integer, so it can also be used from other methods without duplication.

=============== Diff against Kernel-nice.605 ===============

Item was changed:
  Number subclass: #Integer
  	instanceVariableNames: ''
+ 	classVariableNames: 'LowBitPerByteTable'
- 	classVariableNames: ''
  	poolDictionaries: ''
  	category: 'Kernel-Numbers'!
  
  !Integer commentStamp: '<historical>' prior: 0!
  I am a common abstract superclass for all Integer implementations. My implementation subclasses are SmallInteger, LargePositiveInteger, and LargeNegativeInteger.
  	
  Integer division consists of:
  	/	exact division, answers a fraction if result is not a whole integer
  	//	answers an Integer, rounded towards negative infinity
  	\\	is modulo rounded towards negative infinity
  	quo: truncated division, rounded towards zero!

Item was changed:
  ----- Method: Integer class>>initialize (in category 'class initialization') -----
  initialize	"Integer initialize"
  	"Ensure we have the right compact class index"
  
  	"LPI has been a compact class forever - just ensure basic correctness"
  	(LargePositiveInteger indexIfCompact = 5) ifFalse:[
  		(Smalltalk compactClassesArray at: 5)
  			ifNil:[LargePositiveInteger becomeCompactSimplyAt: 5]
  			ifNotNil:[self error: 'Unexpected compact class setup']].
  
  	"Cog requires LNI to be compact at 4 (replacing PseudoContext)"
  	(LargeNegativeInteger indexIfCompact = 4) ifFalse:[
  		"PseudoContext will likely get removed at some point so write this test
  		without introducing a hard dependency"
  		(Smalltalk compactClassesArray at: 4) name == #PseudoContext
  			ifTrue:[Smalltalk compactClassesArray at: 4 put: nil].
  		(Smalltalk compactClassesArray at: 4)
  			ifNil:[LargeNegativeInteger becomeCompactSimplyAt: 4]
  			ifNotNil:[self error: 'Unexpected compact class setup']].
+ 		
+ 	self initializeLowBitPerByteTable
  !

Item was added:
+ ----- Method: Integer class>>initializeLowBitPerByteTable (in category 'class initialization') -----
+ initializeLowBitPerByteTable
+ 	"Initialize LowBitPerByteTable which is a ByteArray that contains the index of the lowest set bit of the integers between 1 and 255. It's defined as a class variable because it's used from the instance side and subclasses."
+ 	"The low bits table can be obtained with:
+ 	((1 to: 8) inject: #[1] into: [:lowBits :rank | (lowBits copy at: 1 put: lowBits first + 1; yourself) , lowBits]) allButFirst
+ 	or with it's symmetric pair:
+ 	((1 to: 8) inject: #[1] into: [:lowBits :rank | lowBits, (lowBits copy atLast: 1 put: lowBits last + 1; yourself)]) allButLast."
+ 	
+ 	LowBitPerByteTable := #[1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 6 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 7 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 6 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 8 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 6 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 7 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 6 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 1 3 1 2 1 4 1 2 1 3 1 2 1]!