The Inbox: Collections-ul.494.mcz

A new version of Collections was added to project The Inbox:
http://source.squeak.org/inbox/Collections-ul.494.mcz

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

Name: Collections-ul.494
Author: ul
Time: 25 October 2012, 1:56:50.407 am
UUID: 1b62455b-152d-4ffc-8072-5b6086cb26a8
Ancestors: Collections-cwp.493

- more straightforward String >> #numArgs implementation (early returns, less branches)
- added an optimized version of #canBeToken to ByteSymbol
- removed the sentence about uppercase first letter from String >> #numArgs, because it wasn't true even in 2004

=============== Diff against Collections-cwp.493 ===============

Item was added:
+ ----- Method: ByteSymbol>>canBeToken (in category 'testing') -----
+ canBeToken
+ "Optimized version for the common case."
+
+ | index |
+ index := 0.
+ [ (index := self findSubstring: '~' in: self startingAt: index + 1 matchTable: Tokenish) = 0 ]
+ whileFalse: [
+ (self at: index) == $_ ifFalse: [ ^false ] ].
+ ^true
+ !

Item was changed:
  ----- Method: String>>numArgs (in category 'accessing') -----
  numArgs
+ "Answer either the number of arguments that the receiver would take if considered a selector.  Answer -1 if it couldn't be a selector. It is intended mostly for the assistance of spelling correction."
- "Answer either the number of arguments that the receiver would take if considered a selector.  Answer -1 if it couldn't be a selector.  Note that currently this will answer -1 for anything begining with an uppercase letter even though the system will accept such symbols as selectors.  It is intended mostly for the assistance of spelling correction."
 
  | firstChar numColons start ix |
+ self size = 0 ifTrue: [ ^-1 ].
- self size = 0 ifTrue: [^ -1].
  firstChar := self at: 1.
+ firstChar isSpecial ifTrue: [
+ 2 to: self size do: [ :i | (self at: i) isSpecial ifFalse: [ ^-1 ] ].
+ ^1 ].
+ firstChar isLetter ifFalse: [ ^-1 ].
+ self canBeToken ifFalse: [ ^-1 ].
+ "Fast colon count"
+ numColons := 0.
+ start := 1.
+ [ (ix := self indexOf: $: startingAt: start) > 0 ] whileTrue: [
+ numColons := numColons + 1.
+ start := ix + 1].
+ (numColons > 0 and: [ self last ~= $: ]) ifTrue: [ ^-1 ].
+ ^numColons!
- firstChar isLetter ifTrue:
- [self canBeToken ifFalse: [^ -1].
- "Fast colon count"
- numColons := 0.  start := 1.
- [(ix := self indexOf: $: startingAt: start) > 0] whileTrue:
- [numColons := numColons + 1.
- start := ix + 1].
- ^ (numColons > 0 and: [self last ~= $:])
- ifTrue: [^ -1]
- ifFalse: [numColons]].
- firstChar isSpecial ifTrue:
- [self size = 1 ifTrue: [^ 1].
- 2 to: self size do: [:i | (self at: i) isSpecial ifFalse: [^ -1]].
- ^ 1].
- ^ -1.!