"
COPYRIGHT (c) 1994 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
"{ Package: 'stx:libcomp' }"
Object subclass:#Switch
instanceVariableNames:'expressions values default'
classVariableNames:''
poolDictionaries:''
category:'Programming-Support'
!
!Switch class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1994 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
!
documentation
"
Obsolete: has been replaced by the caseOf: protocol found in Object.
This class provides a switch-expression facility.
Consider this a demo example, nested if's are much more
efficient. However, support for inline switches may be added
to the compiler (as is done in Smalltalk-agents)
- in this case, a switch will be as efficient as any other if.
Beta Testers: Let me know if such a facility is useful and/or needed ...
example:
|a b|
a := 1.
b := 2.
(Switch new)
if:[a > b] then:['a is greater than b'];
if:[a < b] then:['a is less than b'];
otherwise:['a same as b'];
value
"
! !
!Switch class methodsFor:'instance creation'!
new
^ self basicNew initialize
! !
!Switch methodsFor:'cases'!
if:expr then:block
expressions add:expr.
values add:block
!
otherwise:block
default := block
! !
!Switch methodsFor:'evaluation'!
value
1 to:expressions size do:[:index |
(expressions at:index) value ifTrue:[
^ (values at:index) value
]
].
^ default value
! !
!Switch methodsFor:'initialization'!
initialize
expressions := OrderedCollection new.
values := OrderedCollection new.
! !
!Switch class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libcomp/Switch.st,v 1.7 2012-05-29 17:07:49 cg Exp $'
! !