moved upToAll: to positionableStream.
"
COPYRIGHT (c) 1989 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.
"
PeekableStream subclass:#PositionableStream
instanceVariableNames:'collection position readLimit writeLimit'
classVariableNames:'InvalidPositionErrorSignal ErrorDuringFileInSignal ChunkSeparator'
poolDictionaries:''
category:'Streams'
!
!PositionableStream class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1989 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
"
Instances of PositionableStream allow positioning the read pointer.
The PositionableStream class also adds methods for source-chunk reading
and writing, and for filing-in/out of source code.
This is an abstract class.
[author:]
Claus Gittinger
"
! !
!PositionableStream class methodsFor:'initialization'!
initialize
"setup the signal used to handle errors during fileIn"
ErrorDuringFileInSignal isNil ifTrue:[
ErrorDuringFileInSignal := ErrorSignal newSignalMayProceed:true.
ErrorDuringFileInSignal nameClass:self message:#errorDuringFileInSignal.
ErrorDuringFileInSignal notifierString:'error during fileIn'.
InvalidPositionErrorSignal := PositionErrorSignal newSignalMayProceed:true.
InvalidPositionErrorSignal nameClass:self message:#invalidPositionErrorSignal.
InvalidPositionErrorSignal notifierString:'invalid position'.
ChunkSeparator := $!!
]
! !
!PositionableStream class methodsFor:'instance creation'!
on:aCollection
"return a new PositionableStream streaming on aCollection"
^ (self basicNew) on:aCollection
!
on:aCollection from:first to:last
"return a new PositionableStream streaming on aCollection
from first to last"
^ (self basicNew) on:aCollection from:first to:last
!
with:aCollection
"return a new PositionableStream streaming on aCollection,
the stream is positioned to the end of the collection."
^ (self basicNew) with:aCollection
! !
!PositionableStream class methodsFor:'Signal constants'!
invalidPositionErrorSignal
"return the signal raised if positioning is attempted to an
invalid position (i.e. before the begin of the stream or after
the end)"
^ InvalidPositionErrorSignal
! !
!PositionableStream class methodsFor:'constants'!
chunkSeparator
"return the chunk-separation character"
^ ChunkSeparator
! !
!PositionableStream methodsFor:'accessing'!
contents
"return the entire contents of the stream"
^ collection
!
peek
"look ahead for and return the next element"
|peekObject|
peekObject := self next.
self backStep.
^ peekObject
!
peekFor:something
"return true and move past if next == something;
otherwise stay and let position unchanged"
self next == something ifTrue:[
^ true
].
self backStep.
^ false
!
peekForAll:aCollection
"return true and advance if the next elements are the same
as aCollection.
otherwise stay and let the position unchanged"
|oldPos|
oldPos := self position.
(self next:(aCollection size)) = aCollection ifTrue:[
^ true
].
self position:oldPos.
^ false
"Created: 1.3.1997 / 15:11:25 / cg"
!
readLimit:aNumber
"set the read-limit; thats the position at which EOF is returned"
readLimit := aNumber
!
writeLimit:aNumber
"set the writeLimit; thats the position after which writing is prohibited"
writeLimit := aNumber
! !
!PositionableStream methodsFor:'chunk input/output'!
nextChunk
"return the next chunk, i.e. all characters up to the next
exclamation mark. Within the chunk, exclamation marks have to be doubled,
they are undoubled here.
Except for primitive code, in which doubling is not needed (allowed).
This exception was added to make it easier to edit primitive code with
external editors. However, this means, that other Smalltalks cannot always
read chunks containing primitive code
- but that doesnt really matter, since C-primitives are an ST/X feature anyway."
|theString sep newString done thisChar nextChar inPrimitive
index "{ Class:SmallInteger }"
currSize "{ Class:SmallInteger }" |
sep := ChunkSeparator.
theString := String new:500.
currSize := 500.
thisChar := self skipSeparators.
thisChar := self next.
index := 0.
done := false.
inPrimitive := false.
[done] whileFalse:[
((index + 2) <= currSize) ifFalse:[
newString := String new:(currSize * 2).
newString replaceFrom:1 to:currSize with:theString.
currSize := currSize * 2.
theString := newString
].
thisChar isNil ifTrue:[
done := true
] ifFalse:[
(thisChar == $% ) ifTrue:[
nextChar := self peek.
(nextChar == ${ ) ifTrue:[
inPrimitive := true.
index := index + 1.
theString at:index put:thisChar.
thisChar := self next
] ifFalse:[
(nextChar == $} ) ifTrue:[
inPrimitive := false.
index := index + 1.
theString at:index put:thisChar.
thisChar := self next
]
]
] ifFalse:[
inPrimitive ifFalse:[
(thisChar == sep) ifTrue:[
(self peek == sep) ifFalse:[
done := true
] ifTrue:[
self next
]
]
]
]
].
done ifFalse:[
index := index + 1.
theString at:index put:thisChar.
thisChar := self next
]
].
(index == 0) ifTrue:[^ ''].
^ theString copyTo:index
!
nextChunkPut:aString
"put aString as a chunk onto the receiver;
double all exclamation marks except within primitives and append a
single delimiting exclamation mark at the end.
This modification of the chunk format (not doubling exclas in primitive code)
was done to have primitive code more readable and easier be edited in the fileBrowser
or other editors.
Its no incompatibility, since inline primitives are an ST/X special
and code containing ST/X primitives cannot be loaded into other smalltalks anyway."
self nextPutAllAsChunk:aString.
self nextPut:ChunkSeparator
"Modified: 9.12.1995 / 15:56:54 / cg"
!
nextPutAllAsChunk:aString
"put aString as a chunk onto the receiver;
double all exclamation marks except within primitives.
This modification of the chunk format (not doubling exclas in primitive code)
was done to have primitive code more readable and easier be edited in the fileBrowser
or other editors.
Its no incompatibility, since inline primitives are an ST/X special
and code containing ST/X primitives cannot be loaded into other smalltalks anyway."
|sep stopChars inPrimitive character
index "{ Class:SmallInteger }"
endIndex "{ Class:SmallInteger }"
stop "{ Class:SmallInteger }"
next "{ Class:SmallInteger }"|
sep := ChunkSeparator.
stopChars := '{}' copyWith:sep.
inPrimitive := false.
index := 1.
endIndex := aString size.
stop := endIndex + 1.
[index <= endIndex] whileTrue:[
"
find position of next interesting character;
output stuff up to that one in one piece
"
next := aString indexOfAny:stopChars startingAt:index ifAbsent:stop.
((index == 1) and:[next == stop]) ifTrue:[
self nextPutAll:aString
] ifFalse:[
self nextPutAll:aString startingAt:index to:(next - 1)
].
index := next.
(index <= endIndex) ifTrue:[
character := aString at:index.
(character == ${ ) ifTrue:[
"/ starts a primitive
((index > 1) and:[(aString at:index-1) == $%]) ifTrue:[
inPrimitive := true
]
] ifFalse:[
"/ ends a primitive
(character == $} ) ifTrue:[
((index > 1) and:[(aString at:index-1) == $%]) ifTrue:[
inPrimitive := false
]
] ifFalse:[
"/
"/ exclas have to be doubled - except if within a primitive
"/
inPrimitive ifFalse:[
(character == sep) ifTrue:[
self nextPut:sep
]
]
]
].
self nextPut:character.
index := index + 1
]
].
"Modified: 9.12.1995 / 15:56:47 / cg"
!
nextPutChunkSeparator
"append a chunk separator character"
self nextPut:ChunkSeparator
"Created: 13.9.1995 / 17:39:26 / claus"
! !
!PositionableStream methodsFor:'fileIn'!
askForDebug:message
"launch a box asking if a debugger is wanted - used when an error
occurs while filing in"
Smalltalk isInitialized ifFalse:[
'PositionableStream [warning]: fileIn error during startup: ' errorPrint. message errorPrintCR.
^ #debug
].
"/
"/ are we in the startup sequence of an image restart ?
"/
Processor activeProcessIsSystemProcess ifTrue:[
'PositionableStream [warning]: fileIn error during startup: ' errorPrint. message errorPrintCR.
^ #continue
].
^ OptionBox
request:message
label:'Error in fileIn'
form:(WarningBox iconBitmap)
buttonLabels:#('cancel' 'debug' 'continue')
values:#(#abort #debug #continue)
default:#continue.
"Modified: 10.1.1997 / 18:00:56 / cg"
!
fileIn
"file in from the receiver, i.e. read chunks and evaluate them -
return the value of the last chunk."
^ self fileInNotifying:(SourceFileLoader on:self) passChunk:true
!
fileInNextChunkNotifying:someone
"read next chunk, evaluate it and return the result;
someone (which is usually some codeView) is notified of errors.
Filein is done as follows:
read a chunk
if it started with an excla, evaluate it, and let the resulting object
fileIn more chunks.
This is a nice trick, since the methodsFor: expression evaluates to
a ClassCategoryReader which reads and compiles chunks for its class.
However, other than methodsFor expressions are possible - you can
(in theory) create readers for any syntax.
"
^ self fileInNextChunkNotifying:someone passChunk:false
!
fileInNextChunkNotifying:someone passChunk:passChunk
"read next chunk, evaluate it and return the result;
someone (which is usually some codeView) is notified of errors.
Filein is done as follows:
read a chunk
if it started with an excla, evaluate it, and let the resulting object
fileIn more chunks.
This is a nice trick, since the methodsFor: expression evaluates to
a ClassCategoryReader which reads and compiles chunks for its class.
However, other than methodsFor expressions are possible - you can
(in theory) create readers for any syntax.
"
|aString sawExcla rslt done|
self skipSeparators.
self atEnd ifFalse:[
sawExcla := self peekFor:ChunkSeparator.
aString := self nextChunk.
"/
"/ handle empty chunks;
"/ this allows for Squeak code to be filedIn
"/
[aString size == 0
and:[self atEnd not]] whileTrue:[
aString := self nextChunk.
].
aString size ~~ 0 ifTrue:[
passChunk ifTrue:[
someone source:aString
].
sawExcla ifFalse:[
rslt := Smalltalk::Compiler evaluate:aString notifying:someone.
] ifTrue:[
Smalltalk::Compiler emptySourceNotificationSignal handle:[:ex |
^ nil
] do:[
rslt := Smalltalk::Compiler evaluate:aString notifying:someone compile:false.
].
"
usually, the above chunk consists of some methodsFor:-expression
in this case, the returned value is a ClassCategoryReader,
which is used to load & compile the methods ...
"
rslt isNil ifTrue:[
"
however, if that was nil (i.e. some error), we skip chunks
up to the next empty chunk.
"
Transcript showCR:'skipping chunks ...'.
done := false.
[done] whileFalse:[
aString := self nextChunk.
done := (aString size == 0) or:[aString isEmpty].
]
] ifFalse:[
rslt := rslt fileInFrom:self notifying:someone passChunk:passChunk
]
]
]
].
^ rslt
"Modified: 14.10.1997 / 17:10:35 / cg"
!
fileInNotifying:someone passChunk:passChunk
"file in from the receiver, i.e. read chunks and evaluate them -
return the value of the last chunk.
Someone (which is usually some codeView) is notified of errors."
|lastValue pkg spc spaces
packageQuerySignal nameSpaceQuerySignal usedNameSpaceQuerySignal|
packageQuerySignal := Class packageQuerySignal.
nameSpaceQuerySignal := Class nameSpaceQuerySignal.
usedNameSpaceQuerySignal := Class usedNameSpaceQuerySignal.
(someone respondsTo:#packageToInstall) ifFalse:[
pkg := packageQuerySignal raise.
] ifTrue:[
pkg := someone packageToInstall
].
(someone respondsTo:#currentNameSpace) ifFalse:[
spc := nameSpaceQuerySignal raise.
] ifTrue:[
spc := someone currentNameSpace
].
(someone respondsTo:#usedNameSpaces) ifFalse:[
spaces := usedNameSpaceQuerySignal raise.
] ifTrue:[
spaces := someone usedNameSpaces
].
packageQuerySignal answer:pkg
do:[
usedNameSpaceQuerySignal answer:spaces
do:[
nameSpaceQuerySignal answer:spc
do:[
|methodRedefinitionSignal|
methodRedefinitionSignal := Class methodRedefinitionSignal.
"
catch any errors during fileIn
- offer debug/abort/continue choice
"
ErrorSignal handle:[:ex |
|action what sender msg param oldPackage newPackage|
"/ for your convenience ...
ex signal == methodRedefinitionSignal ifTrue:[
param := ex parameter. "/ an association: oldMethod -> newMethod
oldPackage := param key package.
newPackage := param value package.
msg := 'trying to overwrite method:\\ %1\\in package '''
, oldPackage , ''' with method from package ''' , newPackage , ''''
] ifFalse:[
msg := 'error in fileIn: %1'
].
what := ex errorString.
what isNil ifTrue:[
what := ex signal notifierString.
].
"/ handle the case where no GUI has been built in,
"/ just abort the fileIn with a notification
Display isNil ifTrue:[
sender := ex suspendedContext sender.
self notify:(what ,
' in ' , sender receiver class name ,
'>>>' , sender selector).
ex return
].
"/ otherwise ask what should be done now and either
"/ continue or abort the fileIn
action := self askForDebug:(msg bindWith:what) withCRs.
action == #continue ifTrue:[
ex proceed
].
action == #abort ifTrue:[
ex return
].
"/ (ex signal) enterDebuggerWith:ex message:what.
ex reject
] do:[
[self atEnd] whileFalse:[
lastValue := self fileInNextChunkNotifying:someone passChunk:passChunk
]
].
].
].
].
^ lastValue
"Modified: 14.10.1997 / 15:55:11 / cg"
! !
!PositionableStream methodsFor:'positioning'!
backStep
"move backward read position by one"
position <= 0 ifTrue: [^ self positionError].
position := position - 1
!
position
"return the read position"
^ position
!
position:index
"set the read position"
"/ FIX: allow positioning right after last element of stream
"/ ((index > readLimit) or:[index < 0]) ifTrue: [^ self positionError].
((index > (readLimit+1)) or:[index < 0]) ifTrue: [^ self positionError].
position := index
!
reset
"set the read position to the beginning of the collection"
position := "0" 1
!
setToEnd
"set the read position to the end of the collection"
position := readLimit
!
skip:numberToSkip
"skip the next numberToSkip elements"
self position:(position + numberToSkip)
!
skipThroughAll:aCollection
"skip for and through the sequence given by the argument, aCollection;
return nil if not found, self otherwise.
On a successful match, the next read will return elements after aCollection;
if no match was found, the receiver will be positioned at the end.
This is redefined here, to make use of positioning."
|buffer l first idx|
l := aCollection size.
first := aCollection at:1.
[self atEnd] whileFalse:[
buffer := self nextAvailable:l.
buffer = aCollection ifTrue:[
^ self
].
idx := buffer indexOf:first startingAt:2.
idx == 0 ifFalse:[
self position:(self position - l + idx - 1)
]
].
^ nil
"
|s|
s := ReadStream on:'12345678901234567890'.
s skipThroughAll:'901'.
s upToEnd
"
"
|s|
s := ReadStream on:'12345678901234567890'.
s skipThroughAll:'1234'.
s upToEnd
"
"
|s|
s := ReadStream on:'12345678901234567890'.
s skipThroughAll:'999'.
s atEnd
"
"Created: 26.6.1996 / 09:35:35 / cg"
"Modified: 11.1.1997 / 19:16:38 / cg"
!
skipToAll:aCollection
"skip for the sequence given by the argument, aCollection;
return nil if not found, self otherwise.
On a successful match, the next read will return elements of aCollection."
|oldPos buffer l first idx|
oldPos := self position.
l := aCollection size.
first := aCollection at:1.
[self atEnd] whileFalse:[
buffer := self next:l.
buffer = aCollection ifTrue:[
self position:(self position - l).
^ self
].
idx := buffer indexOf:first startingAt:2.
idx == 0 ifFalse:[
self position:(self position - l + idx - 1)
]
].
self position:oldPos.
^ nil
"
|s|
s := ReadStream on:'12345678901234567890'.
s skipToAll:'901'.
s upToEnd
"
"Modified: 26.6.1996 / 09:28:27 / cg"
"Created: 26.6.1996 / 09:35:06 / cg"
! !
!PositionableStream methodsFor:'private'!
contentsSpecies
"return a class of which instances will be returned, when
parts of the collection are asked for.
(see upTo-kind of methods in subclasses)"
^ collection species
!
on:aCollection
"setup for streaming on aCollection"
collection := aCollection.
readLimit := aCollection size.
position := "0" 1
!
on:aCollection from:first to:last
"setup for streaming on aCollection from first to last"
collection := aCollection.
position := first.
readLimit := last
!
positionError
"{ Pragma: +optSpace }"
"report an error when positioning past the end
or before the beginning."
^ InvalidPositionErrorSignal raiseIn:thisContext sender
!
with:aCollection
"setup for streaming to the end of aCollection"
collection := aCollection.
self setToEnd
! !
!PositionableStream methodsFor:'queries'!
isPositionable
"return true, if the stream supports positioning (this one is)"
^ true
! !
!PositionableStream methodsFor:'reading'!
upToAll:aCollection
"read until a subcollection consisisting of the elements in aCollection
is encountered.
Return everything read excluding the elements in aCollection.
The position is left before the collection; i.e. the next
read operations will return those elements.
If no such subcollection is encountered, all elements up to the end
are read and returned.
Compare this with #throughAll: which also reads up to some objects
but positions behind it and DOES include it in the returned
collection."
|answerStream element last rslt|
last := aCollection last.
answerStream := WriteStream on:(self contentsSpecies new).
[self atEnd] whileFalse:[
element := self next.
answerStream nextPut:element.
element == last ifTrue:[
((rslt := answerStream contents) endsWith:aCollection) ifTrue:[
self position:(self position - aCollection size).
^ rslt copyWithoutLast:aCollection size
]
].
].
^ answerStream contents
"
|s|
s := ReadStream on:'hello world'.
Transcript show:'<'; show:(s upToAll:'wo'); showCR:'>'.
Transcript show:'<'; show:(s upToEnd); showCR:'>'.
"
"
|s|
s := ReadStream on:'hello world'.
Transcript show:'<'; show:(s upToAll:'xx'); showCR:'>'.
Transcript showCR:s atEnd.
Transcript show:'<'; show:(s upToEnd); showCR:'>'.
"
"Modified: / 12.1.1998 / 22:06:42 / cg"
"Created: / 12.1.1998 / 22:07:01 / cg"
! !
!PositionableStream methodsFor:'testing'!
atEnd
"return true, if the read-position is at the end"
^ position > readLimit
!
isEmpty
"return true, if the contents of the stream is empty"
^ readLimit == 0
! !
!PositionableStream class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libbasic/PositionableStream.st,v 1.60 1998-01-12 21:10:15 cg Exp $'
! !
PositionableStream initialize!