| 1 | Error subclass: #EmptyStackError
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| 2 | instanceVariableNames: ''
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| 3 | classVariableNames: ''
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| 4 | poolDictionaries: ''
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| 5 | category: 'HowTo-SUnit'!
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| 6 |
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| 7 | |
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| 8 |
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| 9 | Object subclass: #MyElement
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| 10 | instanceVariableNames: 'item next'
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| 11 | classVariableNames: ''
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| 12 | poolDictionaries: ''
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| 13 | category: 'HowTo-SUnit'!
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| 14 |
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| 15 | !MyElement methodsFor: 'accessing' stamp: 'wm 10/26/2012 20:03:47.176'!
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| 16 | item
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| 17 | "Answer the value of item"
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| 18 |
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| 19 | ^ item! !
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| 20 |
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| 21 | !MyElement methodsFor: 'accessing' stamp: 'wm 10/26/2012 20:03:47.193'!
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| 22 | item: anObject
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| 23 | "Set the value of item"
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| 24 |
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| 25 | item := anObject! !
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| 26 |
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| 27 | !MyElement methodsFor: 'accessing' stamp: 'wm 10/26/2012 20:03:47.211'!
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| 28 | next
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| 29 | "Answer the value of next"
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| 30 |
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| 31 | ^ next! !
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| 32 |
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| 33 | !MyElement methodsFor: 'accessing' stamp: 'wm 10/26/2012 20:03:47.224'!
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| 34 | next: anObject
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| 35 | "Set the value of next"
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| 36 |
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| 37 | next := anObject! !
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| 38 |
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| 39 | "-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "!
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| 40 |
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| 41 | MyElement class
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| 42 | instanceVariableNames: ''!
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| 43 |
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| 44 | !MyElement class methodsFor: 'as yet unclassified' stamp: 'wm 10/26/2012 20:04:59.441'!
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| 45 | newWith: anObject andNext: anotherObject
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| 46 | ^ self new
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| 47 | item: anObject;
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| 48 | next: anotherObject! !
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| 49 |
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| 50 | |
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| 51 |
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| 52 | Object subclass: #MyStack
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| 53 | instanceVariableNames: 'head'
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| 54 | classVariableNames: ''
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| 55 | poolDictionaries: ''
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| 56 | category: 'HowTo-SUnit'!
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| 57 |
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| 58 | !MyStack methodsFor: 'as yet unclassified' stamp: 'wm 10/26/2012 19:53:42.303'!
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| 59 | isEmpty
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| 60 | ^ self head isNil! !
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| 61 |
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| 62 | !MyStack methodsFor: 'as yet unclassified' stamp: 'wm 10/26/2012 20:08:25.072'!
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| 63 | pop
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| 64 | | result |
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| 65 | self isEmpty ifTrue: [EmptyStackError signal: 'Cannot pop from empty stack'].
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| 66 | result := self head item.
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| 67 | self head: self head next.
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| 68 | ^ result
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| 69 | ! !
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| 70 |
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| 71 | !MyStack methodsFor: 'as yet unclassified' stamp: 'wm 10/26/2012 20:03:06.602'!
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| 72 | push: anObject
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| 73 | self head: (MyElement newWith: anObject andNext: self head)! !
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| 74 |
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| 75 |
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| 76 | !MyStack methodsFor: 'accessing' stamp: 'wm 10/26/2012 19:54:23.282'!
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| 77 | head
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| 78 | "Answer the value of head"
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| 79 |
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| 80 | ^ head! !
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| 81 |
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| 82 | !MyStack methodsFor: 'accessing' stamp: 'wm 10/26/2012 19:54:23.295'!
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| 83 | head: anObject
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| 84 | "Set the value of head"
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| 85 |
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| 86 | head := anObject! !
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| 87 |
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| 88 | |
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| 89 |
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| 90 | TestCase subclass: #MyStackTest
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| 91 | instanceVariableNames: 'stack'
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| 92 | classVariableNames: ''
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| 93 | poolDictionaries: ''
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| 94 | category: 'HowTo-SUnit'!
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| 95 |
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| 96 | !MyStackTest methodsFor: 'accessing' stamp: 'wm 10/28/2012 17:36:19.845'!
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| 97 | stack
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| 98 | ^ stack! !
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| 99 |
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| 100 | !MyStackTest methodsFor: 'accessing' stamp: 'wm 10/28/2012 17:36:15.529'!
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| 101 | stack: anObject
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| 102 | stack := anObject! !
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| 103 |
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| 104 |
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| 105 | !MyStackTest methodsFor: 'testing' stamp: 'wm 10/28/2012 17:35:24.569'!
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| 106 | setUp
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| 107 | self stack: MyStack new! !
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| 108 |
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| 109 | !MyStackTest methodsFor: 'testing' stamp: 'wm 10/26/2012 19:52:56.721'!
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| 110 | testEmptyStackIsEmpty
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| 111 | self assert: MyStack new isEmpty ! !
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| 112 |
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| 113 | !MyStackTest methodsFor: 'testing' stamp: 'wm 10/26/2012 20:11:29.244'!
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| 114 | testNonEmptyStackIsNotEmpty
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| 115 | self stack push: Object new.
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| 116 | self deny: self stack isEmpty ! !
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| 117 |
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| 118 | !MyStackTest methodsFor: 'testing' stamp: 'wm 10/26/2012 19:55:08.976'!
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| 119 | testPopEmptyStackThrowsAnError
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| 120 | self should: [MyStack new pop] raise: EmptyStackError! !
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| 121 |
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| 122 | !MyStackTest methodsFor: 'testing' stamp: 'wm 10/26/2012 20:15:16.304'!
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| 123 | testPushPrependsElementPopRemovesIt
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| 124 | | o |
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| 125 | o := Object new.
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| 126 | self assert: (self stack push: o) pop equals: o.
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| 127 | self assert: self stack isEmpty ! !
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