Levente Uzonyi uploaded a new version of Files to project The Trunk:
http://source.squeak.org/trunk/Files-ul.104.mcz

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

Name: Files-ul.104
Author: ul
Time: 16 March 2011, 11:49:07.351 pm
UUID: 6857a09e-25e3-d345-b01f-41700e7bda67
Ancestors: Files-ul.103

- introduced CurrentReadOnlySourceFiles which is an exception used to fetch the current read only copies of SourceFiles
- added a new method to SourceFileArray that extracts both the fileIndex and filePosition from a source pointer and passes them to a block.

=============== Diff against Files-ul.103 ===============

Item was added:
+ Exception subclass: #CurrentReadOnlySourceFiles
+ 	instanceVariableNames: ''
+ 	classVariableNames: ''
+ 	poolDictionaries: ''
+ 	category: 'Files-System'!
+ 
+ !CurrentReadOnlySourceFiles commentStamp: 'ul 3/16/2011 23:08' prior: 0!
+ I'm useful to avoid the creation of several read-only copies of the source files. Use me instead of SourceFiles in your code when you need a read-only copy, like here:
+ 
+ CurrentReadOnlySourceFiles at: 1.
+ 
+ To reuse the source files, surround your code the following way:
+ 
+ | currentReadOnlySourceFiles |
+ ...
+ [ <your code using the source files> ]
+ 	on: CurrentReadOnlySourceFiles
+ 	do: [ :ex |
+ 		ex resume: (currentReadOnlySourceFiles
+ 			ifNil: [ currentReadOnlySourceFiles := ex defaultAction ]) ].
+ ...
+ 
+ Note that it's still better to store the source files in a variable in your code, than throwing many exceptions performance wise.!

Item was added:
+ ----- Method: CurrentReadOnlySourceFiles classSide>>at: (in category 'as yet unclassified') -----
+ at: sourceFileIndex
+ 
+ 	^self signal at: sourceFileIndex!

Item was added:
+ ----- Method: CurrentReadOnlySourceFiles>>defaultAction (in category 'as yet unclassified') -----
+ defaultAction
+ 	"Return a read-only copy of SourceFiles."
+ 
+ 	^SourceFiles collect: [ :each |
+ 		each ifNotNil: [
+ 			[ each readOnlyCopy ]
+ 				on: FileDoesNotExistException
+ 				do: [ :ex | nil "file does not exist happens in secure mode" ] ] ]!

Item was added:
+ ----- Method: SourceFileArray>>fileIndexAndPositionFromSourcePointer:do: (in category 'sourcePointer conversion') -----
+ fileIndexAndPositionFromSourcePointer: sourcePointer do: aBlock
+ 
+ 	^aBlock
+ 		value: (self fileIndexFromSourcePointer: sourcePointer)
+ 		value: (self filePositionFromSourcePointer: sourcePointer)!