/usr/share/gnu-smalltalk/examples/EditStream.st is in gnu-smalltalk-common 3.2.5-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 | "======================================================================
|
| `Splitting' stream, useful for editors and the like.
|
|
======================================================================"
"======================================================================
|
| Written by Ulf Dambacher.
|
| This file is part of GNU Smalltalk.
|
| GNU Smalltalk is free software; you can redistribute it and/or modify it
| under the terms of the GNU General Public License as published by the Free
| Software Foundation; either version 2, or (at your option) any later version.
|
| GNU Smalltalk is distributed in the hope that it will be useful, but WITHOUT
| ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
| FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
| details.
|
| You should have received a copy of the GNU General Public License along with
| GNU Smalltalk; see the file COPYING. If not, write to the Free Software
| Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
======================================================================"
Stream subclass: #EditorStream
instanceVariableNames: 'head headEnd tail tailStart overwrite'
classVariableNames: ''
poolDictionaries: ''
category: 'Examples-Useful tools'
!
" headEnd points behind the last valid member of head.
tailStart points to the first valid member of tail!
"
!EditorStream class methodsFor: 'all'!
on: aString
^self new initOn: aString
! !
!EditorStream methodsFor: 'initializing'!
initOn: aColl
tail _ aColl.
head _ aColl species new: 10.
headEnd _ tailStart _ 1.
overwrite _ false.
!
insert
overwrite _ false.
!
overwrite
overwrite _ true.
! !
!EditorStream methodsFor: 'positioning'!
position
^headEnd
!
position: anInt
anInt < headEnd
ifTrue: [ self copyHeadToTail: (headEnd - anInt) ]
ifFalse:[ self copyTailToHead: (anInt - headEnd)]
!
skip: anInt
anInt < 0
ifTrue: [ self copyHeadToTail: anInt negated ]
ifFalse:[ self copyTailToHead: anInt ]
!
toEnd
self copyTailToHead: tail size - tailStart + 1.
!
toPos1
self copyHeadToTail: headEnd.
! !
!EditorStream methodsFor: 'access'!
previous
self skip: -1.
^ self peek
!
next
^ (self next:1) at: 1.
!
next: anInt
| old |
self atEnd ifTrue: [ self error: 'no object to next!'].
old _ headEnd.
self skip: anInt.
^ head copyFrom: old to: headEnd - 1
!
nextPut: anObject
headEnd > head size ifTrue: [head grow].
head at: headEnd put: anObject.
headEnd _ headEnd + 1.
overwrite ifTrue: [ tailStart _ (tailStart min: tail size) + 1].
!
remove: anInt
anInt < 0
ifTrue: [ headEnd _ headEnd + anInt max: 1 ]
ifFalse: [ tailStart _ tailStart + anInt min: tail size +1 ].
!
peek
self atEnd ifTrue: [self error: 'no object to peek!'].
^tail at: tailStart
! !
!EditorStream methodsFor: 'testing'!
atEnd
^ tailStart > tail size
! !
!EditorStream methodsFor: 'contents access'!
head
^ head copyFrom: 1 to: headEnd - 1
!
tail
^ tail copyFrom: tailStart to: tail size
!
contents
^ self head , self tail
!
size
" ^self contents size"
^ headEnd "- 1 " + tail size - tailStart " + 1 ".
! !
!EditorStream methodsFor: 'collection like access'!
at: anInt
^self at: anInt ifAbsent: [ ^self error: 'index out of range'].
!
at: anInt ifAbsent: aBlock
(anInt between: 1 and: self size) ifFalse: [^aBlock value].
anInt < headEnd
ifTrue: [ ^head at: anInt ]
ifFalse: [ ^ tail at: (anInt - headEnd + tailStart)]
!
inject: aValue into: aBlock
1 to: self size do: [ :i | aValue _ aBlock value: aValue
value: (self at: i)].
^aValue
! !
!EditorStream methodsFor: 'private'!
"
oldcopyHeadToTail: anInt
[ (tailStart > 1 and: [headEnd > 1]) and: [anInt > 0]]
whileTrue: [ tailStart _ tailStart - 1.
headEnd _ headEnd - 1.
tail at: tailStart put: (head at: headEnd).
anInt _ anInt - 1].
anInt > 0 ifTrue:
[ tail _ (head copyFrom: (headEnd - anInt max: 1)
to: headEnd - 1),tail.
headEnd _ headEnd - anInt max: 1]
!
oldcopyTailToHead: anInt
[ tailStart <= tail size and: [anInt > 0]]
whileTrue:
[ headEnd > head size ifTrue: [head grow].
head at: headEnd put: (tail at: tailStart).
tailStart _ tailStart +1.
headEnd _ headEnd + 1.
anInt _ anInt - 1 ].
!
"
copyHeadToTail: anInt
| coll i j |
anInt _ anInt min: headEnd - 1.
tailStart <= anInt
ifTrue: [ i _ anInt + 10. " 10 more spaces... "
j _ tail size - tailStart + 1.
coll _ tail species new: i + j.
coll replaceFrom: i + 1 to: i + j
with: tail startingAt: tailStart.
tail _ coll.
tailStart _ i + 1].
tail replaceFrom: tailStart - anInt to: tailStart - 1
with: head startingAt: headEnd - anInt.
headEnd _ headEnd - anInt.
tailStart _ tailStart - anInt.
!
copyTailToHead: anInt
| coll i |
anInt _ anInt min: tail size - tailStart + 1.
headEnd + anInt > head size
ifTrue: [ i _ anInt + 10.
coll _ head species new: i + headEnd - 1.
coll replaceFrom: 1 to: headEnd - 1
with: head startingAt: 1.
head _ coll ].
head replaceFrom: headEnd to: headEnd - 1 + anInt
with: tail startingAt: tailStart.
tailStart _ tailStart + anInt.
headEnd _ headEnd + anInt.
! !
|