A new version of Kernel was added to project The Inbox:
http://source.squeak.org/inbox/Kernel-mha.500.mcz

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

Name: Kernel-mha.500
Author: mha
Time: 23 September 2010, 10:33:16.329 am
UUID: 6386ad34-1295-4277-a2a3-068faac074de
Ancestors: Kernel-mha.499, Kernel-nice.499

third attempt to clean up CompiledMethod's closures protocol:
* leaner implementation of containsBlockClosures using scanFor:
* corrected InstructionStream >> #scanFor: method comment

=============== Diff against Kernel-mha.499 ===============

Item was changed:
  SystemOrganization addCategory: #'Kernel-Chronology'!
  SystemOrganization addCategory: #'Kernel-Classes'!
  SystemOrganization addCategory: #'Kernel-Methods'!
  SystemOrganization addCategory: #'Kernel-Numbers'!
  SystemOrganization addCategory: #'Kernel-Objects'!
  SystemOrganization addCategory: #'Kernel-Processes'!
  SystemOrganization addCategory: #'Kernel-Models'!
- SystemOrganization addCategory: #'Kernel-Tests-ClassBuilder'!

Item was removed:
- ----- Method: CompiledMethod>>allEmbeddedBlockMethods (in category 'closures') -----
- allEmbeddedBlockMethods
- 
- 	| set |
- 	set := OrderedCollection new.
- 	1 to: self numLiterals do: [:i |  | lit |
- 		lit := self literalAt: i.
- 		(lit isKindOf: CompiledMethod) ifTrue: [
- 			set add: lit.
- 			set addAll: lit allEmbeddedBlockMethods.
- 		] ifFalse: [(lit isKindOf: BlockClosure) ifTrue: [
- 			set add: lit method.
- 			set addAll: lit method allEmbeddedBlockMethods
- 		]].
- 	].
- 	^ set!

Item was changed:
  ----- Method: CompiledMethod>>containsBlockClosures (in category 'closures') -----
  containsBlockClosures
+ 	^ self scanner scanFor: [ :bc | bc = 143 "push closure bytecode" ]!
- 
- 	^ self embeddedBlockMethods size > 0!

Item was added:
+ ----- Method: Float>>copySignTo: (in category 'mathematical functions') -----
+ copySignTo: aNumber
+ 	"Return a number with same magnitude as aNumber and same sign as self.
+ 	Implementation note: take care of Float negativeZero, which is considered as having a negative sign."
+ 
+ 	(self > 0 or: [(self at: 1) = 0])  ifTrue: [^ aNumber abs].
+ 	^aNumber abs negated!

Item was changed:
+ ----- Method: Float>>sign (in category 'mathematical functions') -----
- ----- Method: Float>>sign (in category 'testing') -----
  sign
  	"Answer 1 if the receiver is greater than 0, -1 if less than 0, else 0.
  	Handle IEEE-754 negative-zero by reporting a sign of -1"
  
  	self > 0 ifTrue: [^ 1].
  	(self < 0 or: [((self at: 1) bitShift: -31) = 1]) ifTrue: [^ -1].
  	^ 0!

Item was added:
+ ----- Method: Float>>sign: (in category 'mathematical functions') -----
+ sign: aNumber
+ 	"Return a Number with the same sign as aNumber and same magnitude as self.
+ 	Implementation is different from super to handle the special case of Float negativeZero."
+ 
+ 	(self = 0.0 and: [aNumber sign negative]) ifTrue: [^Float negativeZero].
+ 	^aNumber copySignTo: self!

Item was changed:
  ----- Method: InstructionStream>>scanFor: (in category 'scanning') -----
  scanFor: scanBlock
+ 	"Check all bytecode instructions with scanBlock, answer true if scanBlock answers true.
+ 	This can be used to, e.g., check whether a method contains 'push closure' bytecodes like this:
+ 	aMethod scanFor: [ :b | b = 143 ]"
- 	"Answer the index of the first bytecode for which scanBlock
- 	 answers true when supplied with that bytecode."
  
  	| method end byte |
  	method := self method.
  	end := method endPC.
  	[pc <= end] whileTrue: 
  		[(scanBlock value: (byte := method at: pc)) ifTrue:
  			[^true].
  		 pc := self nextPc: byte].
  	^false!

Item was added:
+ ----- Method: Number>>copySignTo: (in category 'mathematical functions') -----
+ copySignTo: aNumber
+ 	"Return a number with same magnitude as aNumber and same sign as self."
+ 
+ 	^ self positive
+ 		ifTrue: [aNumber abs]
+ 		ifFalse: [aNumber abs negated].!

Item was changed:
+ ----- Method: Number>>sign (in category 'mathematical functions') -----
- ----- Method: Number>>sign (in category 'testing') -----
  sign
  	"Answer 1 if the receiver is greater than 0, -1 if less than 0, else 0."
  
  	self > 0 ifTrue: [^1].
  	self < 0 ifTrue: [^-1].
  	^0!

Item was changed:
+ ----- Method: Number>>sign: (in category 'mathematical functions') -----
- ----- Method: Number>>sign: (in category 'converting') -----
  sign: aNumber
+ 	"Return a Number with the same sign as aNumber and same magnitude as self."
- 	"Return a Number with the same sign as aNumber"
  
+ 	^ aNumber copySignTo: self!
- 	^ aNumber positive ifTrue: [self abs] ifFalse: [self abs negated].!