author | Claus Gittinger <cg@exept.de> |
Wed, 08 Mar 2006 19:25:46 +0100 | |
changeset 9256 | 5aeeba42b052 |
parent 9223 | 105cef4c98ac |
child 9641 | 3569174a721e |
permissions | -rw-r--r-- |
1 | 1 |
" |
5 | 2 |
COPYRIGHT (c) 1988 by Claus Gittinger |
159 | 3 |
All Rights Reserved |
1 | 4 |
|
5 |
This software is furnished under a license and may be used |
|
6 |
only in accordance with the terms of that license and with the |
|
7 |
inclusion of the above copyright notice. This software may not |
|
8 |
be provided or otherwise made available to, or used by, any |
|
9 |
other person. No title to or ownership of the software is |
|
10 |
hereby transferred. |
|
11 |
" |
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12 |
||
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General encoding method (#encodeOn:with:)
Stefan Vogel <sv@exept.de>
parents:
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"{ Package: 'stx:libbasic' }" |
a57eeb01c5ab
General encoding method (#encodeOn:with:)
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parents:
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14 |
|
1 | 15 |
Object subclass:#UndefinedObject |
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instanceVariableNames:'' |
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parents:
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17 |
classVariableNames:'CreateMinimumProtocolInNewSubclassQuery' |
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poolDictionaries:'' |
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category:'Kernel-Objects' |
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! |
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||
88 | 22 |
!UndefinedObject class methodsFor:'documentation'! |
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||
24 |
copyright |
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25 |
" |
|
26 |
COPYRIGHT (c) 1988 by Claus Gittinger |
|
159 | 27 |
All Rights Reserved |
1 | 28 |
|
88 | 29 |
This software is furnished under a license and may be used |
30 |
only in accordance with the terms of that license and with the |
|
31 |
inclusion of the above copyright notice. This software may not |
|
32 |
be provided or otherwise made available to, or used by, any |
|
33 |
other person. No title to or ownership of the software is |
|
34 |
hereby transferred. |
|
35 |
" |
|
36 |
! |
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||
38 |
documentation |
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39 |
" |
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1303 | 40 |
there is only one instance of this class: nil, |
41 |
representing an undefined or otherwise unspecified object. |
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88 | 42 |
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43 |
All instance variables, array elements and even method/block local |
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44 |
variables are initially set to nil. |
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1303 | 45 |
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parents:
1958
diff
changeset
|
46 |
Since in Smalltalk/X (and in other smalltalks), nil is represented by |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
changeset
|
47 |
a special pointer value (NULL), there can be only one instance of UndefinedObject, |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
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|
48 |
and no subclassing is possible. |
1303 | 49 |
(to be exact: subclassing UndefinedObject is technically possible, |
50 |
but instances of it would not be recognized as being nil |
|
51 |
- therefore, subclassing is blocked and an error is raised when it is tried) |
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||
53 |
For advanced users: |
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Beside the above role, nil can be subclassed (!!). |
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This creates a class which inherits no protocol whatsoever - not even |
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56 |
the basic interfaces as defined by the Object class. Subclasses of nil |
|
57 |
are useful if all messages send to instances should trap into the |
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#doesNotUnderstand: method. For example, proxy objects are typically defined |
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this way. |
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1294 | 60 |
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[author:] |
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Claus Gittinger |
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88 | 63 |
" |
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! ! |
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1 | 65 |
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2040
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parents:
1958
diff
changeset
|
66 |
!UndefinedObject class methodsFor:'initialization'! |
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parents:
1958
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67 |
|
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parents:
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68 |
initialize |
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|
69 |
CreateMinimumProtocolInNewSubclassQuery isNil ifTrue:[ |
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parents:
1958
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70 |
CreateMinimumProtocolInNewSubclassQuery := QuerySignal new. |
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parents:
1958
diff
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|
71 |
CreateMinimumProtocolInNewSubclassQuery nameClass:self message:#createMinimumProtocolInNewSubclassQuery. |
8ba8b1002902
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parents:
1958
diff
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|
72 |
CreateMinimumProtocolInNewSubclassQuery defaultAnswer:false. |
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parents:
1958
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73 |
]. |
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parents:
1958
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|
74 |
|
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
75 |
" |
8ba8b1002902
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parents:
1958
diff
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|
76 |
UndefinedObject initialize |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
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|
77 |
" |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
changeset
|
78 |
|
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
changeset
|
79 |
"Created: 3.1.1997 / 15:02:40 / cg" |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
80 |
"Modified: 3.1.1997 / 15:18:33 / cg" |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
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|
81 |
! ! |
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parents:
1958
diff
changeset
|
82 |
|
1 | 83 |
!UndefinedObject class methodsFor:'instance creation'! |
84 |
||
85 |
basicNew |
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86 |
"catch new - there MUST be only one nil in the system" |
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87 |
||
88 |
^ nil |
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89 |
! |
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90 |
||
91 |
basicNew:size |
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92 |
"catch new - there MUST be only one nil in the system" |
|
93 |
||
94 |
^ nil |
|
95 |
! ! |
|
96 |
||
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
97 |
!UndefinedObject class methodsFor:'Signal constants'! |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
98 |
|
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
diff
changeset
|
99 |
createMinimumProtocolInNewSubclassQuery |
8ba8b1002902
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parents:
1958
diff
changeset
|
100 |
"return the signal used to ask if the minimum required protocol |
8ba8b1002902
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parents:
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|
101 |
should be created for nil subclasses. |
8ba8b1002902
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parents:
1958
diff
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|
102 |
By default, this is not done, however, the browser answers true |
8ba8b1002902
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Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
103 |
here, to avoid big trouble with nil subclasses which do not define |
8ba8b1002902
avoid intermediate Object subclass creation.
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parents:
1958
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|
104 |
some methods which the inspector needs." |
8ba8b1002902
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parents:
1958
diff
changeset
|
105 |
|
8ba8b1002902
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parents:
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diff
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|
106 |
^ CreateMinimumProtocolInNewSubclassQuery |
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parents:
1958
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|
107 |
|
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parents:
1958
diff
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|
108 |
"Created: 3.1.1997 / 15:05:48 / cg" |
8ba8b1002902
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parents:
1958
diff
changeset
|
109 |
"Modified: 3.1.1997 / 15:06:15 / cg" |
8ba8b1002902
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parents:
1958
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|
110 |
! ! |
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parents:
1958
diff
changeset
|
111 |
|
51 | 112 |
!UndefinedObject class methodsFor:'queries'! |
113 |
||
114 |
canBeSubclassed |
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115 |
"return true, if its allowed to create subclasses of the receiver. |
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3914 | 116 |
Return false here - since it is NOT possible for UndefinedObject. |
117 |
(due to the representation of nil as a 0-pointer)" |
|
51 | 118 |
|
119 |
^ false |
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3914 | 120 |
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121 |
"Modified: / 5.11.1998 / 16:11:43 / cg" |
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122 |
! |
dc3662188b2c
added #hasImmediateInstances for VW compatibility
Claus Gittinger <cg@exept.de>
parents:
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|
123 |
|
dc3662188b2c
added #hasImmediateInstances for VW compatibility
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parents:
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124 |
hasImmediateInstances |
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125 |
"return true if this class has immediate instances |
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126 |
i.e. if the instances are represented in the pointer itself and |
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127 |
no real object header/storage is used for the object. |
2672
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parents:
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|
128 |
Redefined from Behavior" |
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129 |
|
dc3662188b2c
added #hasImmediateInstances for VW compatibility
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parents:
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130 |
^ true |
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added #hasImmediateInstances for VW compatibility
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parents:
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|
131 |
|
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parents:
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132 |
"Created: 3.6.1997 / 12:01:39 / cg" |
4321 | 133 |
! |
134 |
||
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135 |
hasSharedInstances |
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136 |
"return true if this class has shared instances, that is, instances |
8b3118a923d1
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|
137 |
with the same value are identical. |
4654 | 138 |
True returned here - there is only one nil." |
4652
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parents:
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diff
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|
139 |
|
8b3118a923d1
added #hasSharedInstances & tracing support
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parents:
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diff
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|
140 |
^ true |
8b3118a923d1
added #hasSharedInstances & tracing support
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parents:
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diff
changeset
|
141 |
|
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
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diff
changeset
|
142 |
|
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
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diff
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|
143 |
! |
8b3118a923d1
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parents:
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diff
changeset
|
144 |
|
4321 | 145 |
isBuiltInClass |
146 |
"return true, if this class is known by the run-time-system, |
|
147 |
i.e. you cannot add/remove instance variables without recompiling |
|
148 |
the VM. |
|
149 |
Here, true is returned for myself, false for subclasses." |
|
150 |
||
151 |
^ self == UndefinedObject |
|
152 |
||
51 | 153 |
! ! |
154 |
||
5699 | 155 |
!UndefinedObject methodsFor:'binary storage'! |
156 |
||
157 |
storeBinaryOn: stream manager: manager |
|
158 |
"store a binary representation of the receiver on stream; |
|
159 |
redefined, since true is stored with a special type-code" |
|
160 |
||
161 |
stream nextPut: manager codeForNil |
|
162 |
! ! |
|
163 |
||
2416 | 164 |
!UndefinedObject methodsFor:'converting'! |
165 |
||
8305 | 166 |
asBoolean |
167 |
^ false |
|
168 |
! |
|
169 |
||
2416 | 170 |
literalArrayEncoding |
171 |
"encode myself as an array literal, from which a copy of the receiver |
|
172 |
can be reconstructed with #decodeAsLiteralArray." |
|
173 |
||
174 |
^ self |
|
175 |
||
176 |
"Created: 25.2.1997 / 19:18:47 / cg" |
|
177 |
! ! |
|
178 |
||
695 | 179 |
!UndefinedObject methodsFor:'copying'! |
180 |
||
181 |
copy |
|
182 |
"return a shallow copy of myself |
|
183 |
- since there is only one nil in the system return self" |
|
184 |
||
185 |
^ self |
|
186 |
! |
|
187 |
||
188 |
deepCopy |
|
189 |
"return a deep copy of myself |
|
190 |
- since there is only one nil in the system return self" |
|
191 |
||
192 |
^ self |
|
193 |
! |
|
194 |
||
195 |
deepCopyUsing:aDictionary |
|
196 |
"return a deep copy of myself |
|
8383 | 197 |
- since there is only one nil in the system, return self" |
695 | 198 |
|
199 |
^ self |
|
200 |
! |
|
201 |
||
202 |
shallowCopy |
|
203 |
"return a shallow copy of myself |
|
204 |
- since there is only one nil in the system return self" |
|
205 |
||
206 |
^ self |
|
207 |
! |
|
208 |
||
209 |
simpleDeepCopy |
|
210 |
"return a deep copy of myself |
|
211 |
- since there is only one nil in the system return self" |
|
212 |
||
213 |
^ self |
|
214 |
! ! |
|
215 |
||
3166 | 216 |
!UndefinedObject methodsFor:'dependents access'! |
217 |
||
218 |
addDependent:someObject |
|
219 |
"raise an error here - nil may not have dependents" |
|
220 |
||
4530
793b116fef3e
error: vs. error:mayProceed:
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parents:
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|
221 |
self error:'nil may not have dependents' mayProceed:true |
793b116fef3e
error: vs. error:mayProceed:
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parents:
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diff
changeset
|
222 |
|
3166 | 223 |
! |
224 |
||
3183 | 225 |
dependents |
226 |
"nil has no dependents" |
|
227 |
||
228 |
^#() |
|
229 |
! |
|
230 |
||
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
231 |
release |
3166 | 232 |
"ignored here - nil has no dependents" |
3183 | 233 |
! |
3166 | 234 |
|
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
235 |
removeDependent:someObject |
3183 | 236 |
"ignored here - nil has no dependents" |
3166 | 237 |
! ! |
238 |
||
1 | 239 |
!UndefinedObject methodsFor:'error catching'! |
240 |
||
241 |
basicAt:index |
|
242 |
"catch array access - its illegal |
|
243 |
defined here since basicAt: in Object ommits the nil-check" |
|
244 |
||
245 |
^ self notIndexed |
|
246 |
! |
|
247 |
||
248 |
basicAt:index put:anObject |
|
249 |
"catch array access - its illegal |
|
250 |
defined here since basicAt:put: in Object ommits the nil-check" |
|
251 |
||
252 |
^ self notIndexed |
|
253 |
! ! |
|
254 |
||
255 |
!UndefinedObject methodsFor:'printing & storing'! |
|
256 |
||
63 | 257 |
printOn:aStream |
258 |
"append a printed representation of the receiver to the |
|
259 |
argument, aStream" |
|
260 |
||
261 |
aStream nextPutAll:'nil' |
|
262 |
! |
|
263 |
||
695 | 264 |
printString |
265 |
"return a string for printing myself" |
|
266 |
||
267 |
^ 'nil' |
|
268 |
! |
|
269 |
||
63 | 270 |
storeOn:aStream |
271 |
"append a printed representation of the receiver to the |
|
272 |
argument, aStream, which allows reconstruction of it" |
|
273 |
||
274 |
^ self printOn:aStream |
|
695 | 275 |
! |
276 |
||
277 |
storeString |
|
278 |
"return a string for storing myself" |
|
279 |
||
280 |
^ 'nil' |
|
1 | 281 |
! ! |
2 | 282 |
|
5557 | 283 |
!UndefinedObject methodsFor:'queries'! |
284 |
||
285 |
basicSize |
|
286 |
"return the number of indexed instvars |
|
287 |
defined here since size in Object ommits the nil-check" |
|
288 |
||
289 |
^ 0 |
|
290 |
! |
|
291 |
||
292 |
size |
|
293 |
"return the number of indexed instvars |
|
294 |
defined here since size in Object ommits the nil-check" |
|
295 |
||
296 |
^ 0 |
|
297 |
! ! |
|
5471
a57eeb01c5ab
General encoding method (#encodeOn:with:)
Stefan Vogel <sv@exept.de>
parents:
4682
diff
changeset
|
298 |
|
77 | 299 |
!UndefinedObject methodsFor:'subclass creation'! |
300 |
||
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
301 |
nilSubclass:action |
356 | 302 |
"common helper for subclass creation. |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
303 |
Creates a nil-superclass class. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
304 |
If the CreateMinimumProtocolInNewSubclassQuery answers true, |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
305 |
entries for the minimum required protocol (#class, #isBehavior |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
306 |
and #doesNotUnderstand:) are also automatically created. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
307 |
(this query is typically answered by the browser) |
356 | 308 |
These are required to avoid getting into deep trouble when |
309 |
inspecting or debugging instances of this new class. |
|
310 |
The methods get a modified source code to remind you that these |
|
311 |
methods were automatically generated." |
|
312 |
||
1461
dd25bb1e9973
Use methodDictionary instead of selector/method arrays.
Stefan Vogel <sv@exept.de>
parents:
1303
diff
changeset
|
313 |
|newClass methodDict method| |
202 | 314 |
|
1461
dd25bb1e9973
Use methodDictionary instead of selector/method arrays.
Stefan Vogel <sv@exept.de>
parents:
1303
diff
changeset
|
315 |
Class withoutUpdatingChangesDo:[ |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
316 |
newClass := action value |
77 | 317 |
]. |
318 |
newClass notNil ifTrue:[ |
|
1029
c469a63e88e2
only redefine #class/#isbehavior/#doesNotUnderstand once (if no methods are present yet)
Claus Gittinger <cg@exept.de>
parents:
695
diff
changeset
|
319 |
newClass setSuperclass:nil. |
1803
754f9205b651
meta's superclass should be class - not Object.
Claus Gittinger <cg@exept.de>
parents:
1638
diff
changeset
|
320 |
newClass class setSuperclass:Class. |
356 | 321 |
|
1461
dd25bb1e9973
Use methodDictionary instead of selector/method arrays.
Stefan Vogel <sv@exept.de>
parents:
1303
diff
changeset
|
322 |
newClass methodDictionary size == 0 ifTrue:[ |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
323 |
Class addChangeRecordForClass:newClass. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
324 |
|
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
325 |
CreateMinimumProtocolInNewSubclassQuery query |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
326 |
ifTrue:[ |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
327 |
" |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
328 |
copy over method objects from Object |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
329 |
and modify the source code |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
330 |
" |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
331 |
methodDict := MethodDictionary new:3. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
332 |
#(#class #isBehavior #doesNotUnderstand:) do:[:sel| |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
333 |
method := (Object compiledMethodAt:sel) copy. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
334 |
method source: method source , ' |
356 | 335 |
" |
336 |
*** WARNING |
|
337 |
*** |
|
338 |
*** this method has been automatically created, |
|
339 |
*** since all nil-subclasses should respond to some minimum required |
|
340 |
*** protocol. |
|
341 |
*** |
|
342 |
*** Inspection and/or debugging of instances may not be possible, |
|
343 |
*** if you remove/change this method. |
|
344 |
" |
|
345 |
'. |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
346 |
methodDict at:sel put:method. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
347 |
"/ newClass addChangeRecordForMethod:method |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
348 |
]. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
349 |
newClass methodDictionary:methodDict. |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
350 |
] |
1029
c469a63e88e2
only redefine #class/#isbehavior/#doesNotUnderstand once (if no methods are present yet)
Claus Gittinger <cg@exept.de>
parents:
695
diff
changeset
|
351 |
] |
77 | 352 |
]. |
353 |
^ newClass |
|
1029
c469a63e88e2
only redefine #class/#isbehavior/#doesNotUnderstand once (if no methods are present yet)
Claus Gittinger <cg@exept.de>
parents:
695
diff
changeset
|
354 |
|
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
355 |
"Modified: / 3.1.1997 / 15:53:21 / cg" |
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
356 |
"Created: / 3.1.1997 / 16:00:34 / cg" |
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
357 |
"Modified: / 18.3.1999 / 18:29:58 / stefan" |
202 | 358 |
! |
359 |
||
9256 | 360 |
subclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString poolDictionaries:pool |
361 |
"create a new class which has nil as superclass |
|
362 |
- i.e. traps into #doesNotUnderstand: for all of its messages." |
|
363 |
||
364 |
^ self |
|
365 |
subclass:nameSymbol |
|
366 |
instanceVariableNames:instVarNameString |
|
367 |
classVariableNames:classVarString |
|
368 |
poolDictionaries:pool |
|
369 |
category:(Class defaultCategoryForSTVorVAGEClasses). |
|
370 |
! |
|
371 |
||
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
372 |
subclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString poolDictionaries:pool category:cat |
202 | 373 |
"create a new class which has nil as superclass |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
374 |
- i.e. traps into #doesNotUnderstand: for all of its messages." |
202 | 375 |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
376 |
^ self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
377 |
nilSubclass:[ |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
378 |
Object class |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
379 |
name:nameSymbol |
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
380 |
inEnvironment:(Class nameSpaceQuerySignal query) |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
381 |
subclassOf:self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
382 |
instanceVariableNames:instVarNameString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
383 |
variable:false |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
384 |
words:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
385 |
pointers:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
386 |
classVariableNames:classVarString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
387 |
poolDictionaries:pool |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
388 |
category:cat |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
389 |
comment:nil |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
390 |
changed:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
391 |
] |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
392 |
|
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
393 |
"Modified: / 3.1.1997 / 16:00:39 / cg" |
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
394 |
"Modified: / 18.3.1999 / 18:30:07 / stefan" |
695 | 395 |
! |
396 |
||
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
397 |
variableByteSubclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString poolDictionaries:pool category:cat |
695 | 398 |
"create a new class which has nil as superclass |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
399 |
- i.e. traps into #doesNotUnderstand: for all of its messages." |
695 | 400 |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
401 |
^ self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
402 |
nilSubclass:[ |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
403 |
Object class |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
404 |
name:nameSymbol |
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
405 |
inEnvironment:(Class nameSpaceQuerySignal query) |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
406 |
subclassOf:self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
407 |
instanceVariableNames:instVarNameString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
408 |
variable:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
409 |
words:false |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
410 |
pointers:false |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
411 |
classVariableNames:classVarString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
412 |
poolDictionaries:pool |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
413 |
category:cat |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
414 |
comment:nil |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
415 |
changed:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
416 |
] |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
417 |
|
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
418 |
"Modified: / 3.1.1997 / 16:00:42 / cg" |
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
419 |
"Modified: / 18.3.1999 / 18:30:11 / stefan" |
695 | 420 |
! |
77 | 421 |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
422 |
variableSubclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString poolDictionaries:pool category:cat |
159 | 423 |
"create a new class which has nil as superclass |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
424 |
- i.e. traps into #doesNotUnderstand: for all of its messages." |
77 | 425 |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
426 |
^ self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
427 |
nilSubclass:[ |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
428 |
Object class |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
429 |
name:nameSymbol |
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
430 |
inEnvironment:(Class nameSpaceQuerySignal query) |
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
431 |
subclassOf:self |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
432 |
instanceVariableNames:instVarNameString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
433 |
variable:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
434 |
words:false |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
435 |
pointers:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
436 |
classVariableNames:classVarString |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
437 |
poolDictionaries:pool |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
438 |
category:cat |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
439 |
comment:nil |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
440 |
changed:true |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
441 |
] |
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
442 |
|
4060
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
443 |
"Modified: / 3.1.1997 / 16:00:45 / cg" |
1048a3abf128
Use #query instead of #raise when invoking QuerySignals
Stefan Vogel <sv@exept.de>
parents:
3914
diff
changeset
|
444 |
"Modified: / 18.3.1999 / 18:30:16 / stefan" |
695 | 445 |
! ! |
446 |
||
7262 | 447 |
!UndefinedObject methodsFor:'subclass creation-private'! |
5745 | 448 |
|
449 |
subclass:nameSymbol instanceVariableNames:instVarNameString classVariableNames:classVarString poolDictionaries:pool privateIn:ownerClass |
|
450 |
"create a new private class which has nil as superclass |
|
451 |
- i.e. traps into #doesNotUnderstand: for all of its messages." |
|
452 |
||
453 |
^ self |
|
454 |
nilSubclass:[ |
|
455 |
Object class |
|
456 |
name:nameSymbol |
|
457 |
inEnvironment:ownerClass |
|
458 |
subclassOf:self |
|
459 |
instanceVariableNames:instVarNameString |
|
460 |
variable:false |
|
461 |
words:true |
|
462 |
pointers:true |
|
463 |
classVariableNames:classVarString |
|
464 |
poolDictionaries:pool |
|
465 |
category:ownerClass category |
|
466 |
comment:nil |
|
467 |
changed:true |
|
468 |
] |
|
469 |
||
470 |
"Modified: / 3.1.1997 / 16:00:39 / cg" |
|
471 |
"Modified: / 18.3.1999 / 18:30:07 / stefan" |
|
472 |
! ! |
|
473 |
||
695 | 474 |
!UndefinedObject methodsFor:'testing'! |
475 |
||
1868 | 476 |
? defaultValue |
3466 | 477 |
"a syntactic shugar-piece: |
478 |
if the receiver is nil, return the defaultValue; |
|
1868 | 479 |
otherwise, return the receiver. |
480 |
This method is redefined from Object; |
|
481 |
the argument is retuned unconditionally here. |
|
482 |
||
1958 | 483 |
Thus, if foo and bar are simple variables or constants, |
484 |
foo ? bar |
|
485 |
is the same as: |
|
486 |
(foo isNil ifTrue:[bar] ifFalse:[foo]) |
|
487 |
||
488 |
if they are message sends, the equivalent code is: |
|
489 |
[ |
|
490 |
|t1 t2| |
|
491 |
||
492 |
t1 := foo. |
|
493 |
t2 := bar. |
|
494 |
t1 isNil ifTrue:[t2] ifFalse:[t1] |
|
495 |
] value |
|
496 |
||
1868 | 497 |
Can be used to provide defaultValues to variables, |
498 |
as in: |
|
1958 | 499 |
foo := arg ? #defaultValue |
1868 | 500 |
" |
501 |
||
502 |
^ defaultValue |
|
503 |
||
504 |
" |
|
505 |
1 ? #default |
|
506 |
nil ? #default |
|
507 |
" |
|
508 |
||
3466 | 509 |
"Created: / 4.11.1996 / 20:37:09 / cg" |
510 |
"Modified: / 19.5.1998 / 17:39:36 / cg" |
|
1868 | 511 |
! |
512 |
||
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
513 |
?? defaultValue |
3466 | 514 |
"a syntactic shugar-piece: |
515 |
much like ?, but sends value to the argument if required. |
|
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
516 |
If the receiver is nil, return the defaultValues value; |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
517 |
otherwise, return the receiver. |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
518 |
This method is redefined from Object. |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
519 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
520 |
Thus, if foo and bar are simple variables or constants, |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
521 |
foo ?? bar |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
522 |
is the same as: |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
523 |
(foo isNil ifTrue:[bar value] ifFalse:[foo]) |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
524 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
525 |
if they are message sends, the equivalent code is: |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
526 |
[ |
3466 | 527 |
|t| |
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
528 |
|
3466 | 529 |
t := foo. |
530 |
t isNil ifTrue:[bar value] ifFalse:[t] |
|
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
531 |
] value |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
532 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
533 |
Can be used to provide defaultValues to variables, |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
534 |
as in: |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
535 |
foo := arg ?? [something] |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
536 |
" |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
537 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
538 |
^ defaultValue value |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
539 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
540 |
" |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
541 |
1 ?? #default |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
542 |
nil ?? #default |
6069 | 543 |
1 ?? [Date today] |
544 |
nil ?? [Date today] |
|
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
545 |
" |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
546 |
|
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
547 |
"Created: / 4.11.1996 / 20:37:09 / cg" |
3466 | 548 |
"Modified: / 19.5.1998 / 17:42:10 / cg" |
3464
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
549 |
! |
b0009b3ea4f2
added ?? - much like ?, but sends #value to its argument.
Claus Gittinger <cg@exept.de>
parents:
3183
diff
changeset
|
550 |
|
7108
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
551 |
checkNilFileStream |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
552 |
"Do nothing if this is a valid FileStream |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
553 |
(i.e. the previous open operation was successful). |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
554 |
Also implemented in UndefinedObject, to raise an Error there. |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
555 |
|
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
556 |
This is an aid for converting from the old error reporting (returning nil) |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
557 |
to the new error reporting (with real Exceptions. |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
558 |
|
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
559 |
It will vanish as soon as the conversion has been done" |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
560 |
|
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
561 |
^ ExternalStream openErrorSignal raise |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
562 |
! |
90b7cfc06ab8
More openErrorSignal change preparations
Stefan Vogel <sv@exept.de>
parents:
6932
diff
changeset
|
563 |
|
695 | 564 |
hash |
565 |
"return an integer useful as a hash key" |
|
566 |
||
567 |
^ 0 |
|
568 |
! |
|
569 |
||
570 |
identityHash |
|
571 |
"return an integer useful as a hash key" |
|
572 |
||
573 |
^ 0 |
|
574 |
! |
|
575 |
||
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
576 |
ifNil:aBlockOrValue |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
577 |
"return myself, or the result from evaluating the argument, if I am nil. |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
578 |
This is much like #?, but sends #value to the argument in case of a nil |
5796 | 579 |
receiver. |
580 |
Notice: |
|
581 |
This method is open coded (inlined) by the compiler(s) |
|
582 |
- redefining it may not work as expected." |
|
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
583 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
584 |
^ aBlockOrValue value |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
585 |
! |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
586 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
587 |
ifNil:nilBlockOrValue ifNotNil:notNilBlockOrValue |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
588 |
"return the value of the first arg, if I am nil, |
5796 | 589 |
the result from evaluating the 2nd argument, if I am not nil. |
590 |
Notice: |
|
591 |
This method is open coded (inlined) by the compiler(s) |
|
592 |
- redefining it may not work as expected." |
|
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
593 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
594 |
^ nilBlockOrValue value |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
595 |
! |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
596 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
597 |
ifNotNil:aBlockOrValue |
5796 | 598 |
"return myself if nil, or the result from evaluating the argument, if I am not nil. |
599 |
Notice: |
|
600 |
This method is open coded (inlined) by the compiler(s) |
|
601 |
- redefining it may not work as expected." |
|
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
602 |
|
8574 | 603 |
^ nil |
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
604 |
! |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
605 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
606 |
ifNotNil:notNilBlockOrValue ifNil:nilBlockOrValue |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
607 |
"return the value of the 2nd arg, if I am nil, |
5796 | 608 |
the result from evaluating the 1st argument, if I am not nil. |
609 |
Notice: |
|
610 |
This method is open coded (inlined) by the compiler(s) |
|
611 |
- redefining it may not work as expected." |
|
4339
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
612 |
|
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
613 |
^ nilBlockOrValue value |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
614 |
! |
18c19912a67c
added #ifNil and friends - squeak compatibility.
Claus Gittinger <cg@exept.de>
parents:
4321
diff
changeset
|
615 |
|
8574 | 616 |
ifNotNilDo:aBlock |
617 |
"if the reciever is non-nil, return the value of aBlock, passing myself as argument. |
|
618 |
Otherwise do nothing and return nil." |
|
619 |
||
620 |
^ nil |
|
621 |
! |
|
622 |
||
6181 | 623 |
isEmptyOrNil |
8833 | 624 |
"return true if I am nil or an empty collection - since I am nil, return true. |
625 |
(from Sqeak)" |
|
6181 | 626 |
|
627 |
^ true |
|
628 |
||
629 |
"Created: / 13.11.2001 / 13:16:40 / cg" |
|
6182 | 630 |
"Modified: / 13.11.2001 / 13:28:47 / cg" |
6181 | 631 |
! |
632 |
||
695 | 633 |
isLiteral |
4652
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
634 |
"return true, if the receiver can be used as a literal constant in ST syntax |
695 | 635 |
(i.e. can be used in constant arrays)" |
77 | 636 |
|
695 | 637 |
^ true |
638 |
! |
|
639 |
||
640 |
isNil |
|
9223 | 641 |
"Return true, if the receiver is nil. |
642 |
Since I am definitely nil, unconditionally return true here. |
|
3044 | 643 |
Notice: |
9223 | 644 |
This method is open coded (inlined) by the compiler(s) |
645 |
- redefining it may not work as expected." |
|
695 | 646 |
|
647 |
^ true |
|
648 |
! |
|
649 |
||
6068
1d5ca1175f3f
added #isNilOrEmptyCollection
Claus Gittinger <cg@exept.de>
parents:
5796
diff
changeset
|
650 |
isNilOrEmptyCollection |
8833 | 651 |
"return true if I am nil or an empty collection - false here. |
652 |
Obsolete, use isEmptyOrNil." |
|
653 |
||
654 |
<resource:#obsolete> |
|
6068
1d5ca1175f3f
added #isNilOrEmptyCollection
Claus Gittinger <cg@exept.de>
parents:
5796
diff
changeset
|
655 |
|
1d5ca1175f3f
added #isNilOrEmptyCollection
Claus Gittinger <cg@exept.de>
parents:
5796
diff
changeset
|
656 |
^ true |
6182 | 657 |
|
658 |
"Modified: / 13.11.2001 / 13:28:15 / cg" |
|
6068
1d5ca1175f3f
added #isNilOrEmptyCollection
Claus Gittinger <cg@exept.de>
parents:
5796
diff
changeset
|
659 |
! |
1d5ca1175f3f
added #isNilOrEmptyCollection
Claus Gittinger <cg@exept.de>
parents:
5796
diff
changeset
|
660 |
|
6932 | 661 |
notEmptyOrNil |
662 |
"Squeak compatibility: |
|
663 |
return true if I am neither nil nor an empty collection." |
|
664 |
||
665 |
^ false |
|
666 |
! |
|
667 |
||
695 | 668 |
notNil |
9223 | 669 |
"Return true, if the receiver is not nil. |
670 |
Since I am definitely nil, unconditionally return false here. |
|
3044 | 671 |
Notice: |
9223 | 672 |
This method is open coded (inlined) by the compiler(s) |
673 |
- redefining it may not work as expected." |
|
77 | 674 |
|
695 | 675 |
^ false |
77 | 676 |
! ! |
695 | 677 |
|
4652
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
678 |
!UndefinedObject methodsFor:'tracing'! |
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
679 |
|
4682 | 680 |
traceInto:aRequestor level:level from:referrer |
4652
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
681 |
"double dispatch into tracer, passing my type implicitely in the selector" |
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
682 |
|
4682 | 683 |
^ aRequestor traceUndefinedObject:self level:level from:referrer |
4652
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
684 |
|
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
685 |
|
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
686 |
! ! |
8b3118a923d1
added #hasSharedInstances & tracing support
Claus Gittinger <cg@exept.de>
parents:
4530
diff
changeset
|
687 |
|
8395
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
688 |
!UndefinedObject methodsFor:'visiting'! |
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
689 |
|
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
690 |
acceptVisitor:aVisitor with:aParameter |
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
691 |
|
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
692 |
^ aVisitor visitNilWith:aParameter |
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
693 |
! ! |
6bd97113cb4c
Generalize visitor pattern and define #visit...:with: -methods instead
Stefan Vogel <sv@exept.de>
parents:
8383
diff
changeset
|
694 |
|
695 | 695 |
!UndefinedObject class methodsFor:'documentation'! |
696 |
||
697 |
version |
|
9256 | 698 |
^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.64 2006-03-08 18:25:46 cg Exp $' |
695 | 699 |
! ! |
6932 | 700 |
|
2040
8ba8b1002902
avoid intermediate Object subclass creation.
Claus Gittinger <cg@exept.de>
parents:
1958
diff
changeset
|
701 |
UndefinedObject initialize! |