"

 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.

"

Object subclass:#Switch

	 instanceVariableNames:'expressions values default'

	 classVariableNames:''

	 poolDictionaries:''

	 category:'System-Misc'

!

Switch comment:'

COPYRIGHT (c) 1994 by Claus Gittinger

              All Rights Reserved

'!

!Switch class methodsFor:'documentation'!

documentation

    "

     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.

     Testers: Let me know if such a facility is useful and/or needed ...

     example:

        (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

    "

!

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.

"

!

version

"

"

! !

!Switch class methodsFor:'instance creation'!

new

    ^ self basicNew initialize

! !

!Switch methodsFor:'cases'!

otherwise:block

    default := block

!

if:expr then:block

    expressions add:expr.

    values add: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.

! !