"{ Encoding: utf8 }"

"

 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.

"

"{ Package: 'stx:libbasic' }"

"{ NameSpace: Smalltalk }"

UninterpretedBytes variableByteSubclass:#CharacterArray

	instanceVariableNames:''

	classVariableNames:'PreviousMatch DecoderTables EncoderTables DecodingFailedSignal

		EncodingFailedSignal'

	poolDictionaries:''

	category:'Collections-Text'

!

!CharacterArray class methodsFor:'documentation'!

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.

"

!

documentation

"

    CharacterArray is a superclass for all kinds of Strings (i.e.

    (singleByte-)Strings, TwoByteStrings, UnicodeStrings

    and whatever my come in the future.

    This class is abstract, meaning that there are no instances of it;

    concrete subclasses define how the characters are stored (i.e. either as

    single byte, two-byte or four byte strings).

    All this class does is provide common protocol for concrete subclasses.

    Notice:

	internally, ST/X uses a unicode encoding for ALL characters - both

	for individual chatacter entities and for strings of characters.

	When reading/writing files in different encodings, the conversion is

	done at read/write time by use of a CharacterEncoder instance.

	These know how to convert to a wide range of encodings.

    Also notice:

	UTF8 and UTF16 are external encodings of a Unicode string; they are never

	used internally. When interacting with a UTF8 interface (OS-API or files),

	you should convert UTF8 into the internal full Unicode right at the interface.

	Do not keep UTF8 around internally as String instances.

	The reason is that UTF8 makes it harder to manipulate strings (for example

	to insert/extract substrings or to get its size. Of such operations would

	require a scan of the UTF8, which would complicate them).

	Of course, there may be rare exceptions to this, for example if a file's contents

	is treated as raw data, and the strings have to be copied/shuffled around only,

	without any real processing on it.

    [author:]

	Claus Gittinger

    [see also:]

	String TwoByteString Unicode16String Uniode32String

	StringCollection

"

! !

!CharacterArray class methodsFor:'initialization'!

initialize

    DecodingFailedSignal isNil ifTrue:[

	DecodingFailedSignal := DecodingError.

	DecodingFailedSignal notifierString:'error during decode'.

	EncodingFailedSignal :=EncodingError.

	EncodingFailedSignal notifierString:'error during encode'.

    ]

    "

     CharacterArray initialize

    "

    "Modified: 3.8.1997 / 18:15:59 / cg"

! !

!CharacterArray class methodsFor:'instance creation'!

basicNew

    "return a new empty string"

    ^ self basicNew:0

!

fromBytes:aByteCollection

    "return an instance of the receiver class,

     taking untranslated bytes from the argument, aByteCollection.

     Only useful, when reading twoByteStrings from external sources."

    |mySize nBytes newString dstIdx|

    nBytes := aByteCollection size.

    mySize := self basicNew bitsPerCharacter.

    mySize == 16 ifTrue:[

	newString := self uninitializedNew:(nBytes // 2).

	dstIdx := 1.

	aByteCollection pairWiseDo:[:hi :lo |

	    newString at:dstIdx put:(Character value:(hi bitShift:8)+lo).

	    dstIdx := dstIdx + 1

	].

	^ newString.

    ].

    ^ (self uninitializedNew:nBytes) replaceFrom:1 with:aByteCollection

    "

     Unicode16String fromBytes:#[16r02 16r20]

    "

    "Modified: 30.6.1997 / 20:08:37 / cg"

!

fromString:aString

    "return a copy of the argument, aString"

    ^ (self uninitializedNew:aString size) replaceFrom:1 with:aString

    "

	Unicode16String fromString:'hello'

    "

!

fromStringCollection:aCollectionOfStrings

    "return new string formed by concatenating a copy of the argument, aString"

    ^ self fromStringCollection:aCollectionOfStrings separatedBy:''

    "

     String fromStringCollection:#('hello' 'world' 'how' 'about' 'this')

    "

    "Created: 20.11.1995 / 15:26:59 / cg"

!

fromStringCollection:aCollectionOfStrings separatedBy:aSeparatorString

    "return new string formed by concatenating a copy of the argument, aString"

    |stream|

    aCollectionOfStrings do:[:eachString |

	stream isNil ifTrue:[

	    stream := self writeStreamClass with:eachString.

	] ifFalse:[

	    stream

		nextPutAll:aSeparatorString;

		nextPutAll:eachString.

	].

    ].

    stream isNil ifTrue:[^ ''].

    ^ stream contents

    "

     String fromStringCollection:#('hello' 'world' 'how' 'about' 'this') separatedBy:' '

     String fromStringCollection:#('hello' 'world' 'how' 'about' 'this') separatedBy:'Ƞ'

     Text fromStringCollection:{'hello'. 'world'. 'how' allBold. 'about'. 'this'. 'äöü'} separatedBy:'Ƞ'

    "

    "Created: 20.11.1995 / 15:32:17 / cg"

!

fromUTF8Bytes:aByteCollection

    "return a new string which represents the characters as decoded

     from the utf8 encoded bytes, aByteCollection.

     Returns either a normal String, or a TwoByteString instance.

     Only useful, when reading twoByteStrings from external sources.

     This only handles up-to 16bit characters"

    ^ self decodeFromUTF8:aByteCollection.

    "

     CharacterArray fromUTF8Bytes:#[ 16r41 16r42 ]

     CharacterArray fromUTF8Bytes:#[ 16rC1 16r02 ]

     CharacterArray fromUTF8Bytes:#[ 16rE0 16r81 16r02 ]

     CharacterArray fromUTF8Bytes:#[ 16rEF 16rBF 16rBF ]

   rfc2279 examples:

     CharacterArray fromUTF8Bytes:#[ 16r41 16rE2 16r89 16rA2 16rCE 16r91 16r2E ]

     CharacterArray fromUTF8Bytes:#[ 16rED 16r95 16r9C 16rEA 16rB5 16rAD 16rEC 16r96 16rB4 ]

     CharacterArray fromUTF8Bytes:#[ 16rE6 16r97 16rA5 16rE6 16r9C 16rAC 16rE8 16rAA 16r9E ]

   invalid:

     CharacterArray fromUTF8Bytes:#[ 16rC0 16r80 ]

     CharacterArray fromUTF8Bytes:#[ 16rE0 16r80 16r80 ]

    "

!

new

    "return a new empty string"

    ^ self basicNew:0

!

readSmalltalkStringFrom:aStreamOrString onError:exceptionBlock

    "read & return the next String from the (character-)stream aStream;

     skipping all whitespace first; return the value of exceptionBlock,

     if no string can be read. The sequence of characters as read from the

     stream must be one as stored via storeOn: or storeString."

    |str collected char|

    str := aStreamOrString readStream.

    "skip whiteSpace"

    str skipSeparators.

    (str peekOrNil == $') ifTrue:[

	str next.

	collected := self writeStream.

	[str atEnd] whileFalse:[

	    char := str next.

	    char == $' ifTrue:[

		"/ look for another quote

		str peekOrNil ~~ $' ifTrue:[

		    "end of string reached"

		    ^ collected contents.

		].

		"eat doubled quote"

		str next.

	    ].

	    ((char ~~ Character return) or:[str peekOrNil ~~ Character lf]) ifTrue:[

		"compress CRLF to LF, but keep a single CR"

		collected nextPut:char.

	    ].

	].

	"if we come here, we reached the end without finding a closing $'"

    ].

    ^ exceptionBlock value

    "

     String readFrom:('''hello world''' readStream)

     String readFrom:('''hello '''' world''' readStream)

     String readFrom:('1 ''hello'' ' readStream)

     String readFrom:('1 ''hello'' ' readStream) onError:['foobar']

    "

    "Created: / 05-07-2006 / 16:41:04 / cg"

    "Modified: / 06-10-2006 / 14:05:32 / cg"

!

writeStreamClass

    "the class used by writeStream.

     Here, we return CharacterWriteStream, which automatically changes

     the underlying collection to a multiByte string (i.e. UnicodeString).

     So you can stream wide characters into it."

    ^ CharacterWriteStream

    "

     String writeStream

    "

    "Created: / 09-01-2011 / 10:37:57 / cg"

! !

!CharacterArray class methodsFor:'Compatibility-VW'!

fromIntegerArray: anArray

    "Answer a new instance of the receiver that is created from the argument, anArray."

    | new |

    new := self new: anArray size.

    1 to: anArray size do:[:index |

	new at: index put: (anArray at: index) asCharacter

    ].

    ^new

    "

     String fromIntegerArray: #[8 127]

    "

! !

!CharacterArray class methodsFor:'Signal constants'!

decodingFailedSignal

    "return the signal, raised when decoding of a string is not possible

     due to invalid characters contained in the source.

     This may happen for example, if a non EUC coded 8-bit string

     is attempted to be decoded into a JIS string."

    ^ DecodingFailedSignal

    "Created: 28.6.1997 / 20:09:55 / cg"

    "Modified: 3.8.1997 / 18:16:47 / cg"

!

encodingFailedSignal

    "return the (query-) signal, raised when encoding of a string is not possible

     due to invalid characters contained in the source."

    ^ EncodingFailedSignal

    "Modified: 28.6.1997 / 20:09:35 / cg"

    "Created: 3.8.1997 / 18:16:40 / cg"

! !

!CharacterArray class methodsFor:'cleanup'!

lowSpaceCleanup

    "cleanup in low-memory situations"

    DecoderTables := EncoderTables := nil

    "

     CharacterArray lowSpaceCleanup

    "

    "Created: 22.2.1996 / 16:30:30 / cg"

    "Modified: 22.2.1996 / 17:58:05 / cg"

! !

!CharacterArray class methodsFor:'encoding & decoding'!

decodeFromUTF8:aStringOrByteCollection

    "return a string which represents the characters as decoded

     from the utf8 encoded bytes, aByteCollection.

     Returns either a normal String, or a TwoByteString instance.

     Only useful, when reading twoByteStrings from external sources.

     This only handles up-to 16bit characters."

    ^ CharacterEncoderImplementations::ISO10646_to_UTF8 new decodeString:aStringOrByteCollection

    "

     CharacterArray fromUTF8Bytes:#[ 16r41 16r42 ]

     CharacterArray fromUTF8Bytes:#[ 16rC1 16r02 ]

     CharacterArray fromUTF8Bytes:#[ 16rE0 16r81 16r02 ]

     CharacterArray fromUTF8Bytes:#[ 16rEF 16rBF 16rBF ]

   rfc2279 examples:

     CharacterArray fromUTF8Bytes:#[ 16r41 16rE2 16r89 16rA2 16rCE 16r91 16r2E ]

     CharacterArray fromUTF8Bytes:#[ 16rED 16r95 16r9C 16rEA 16rB5 16rAD 16rEC 16r96 16rB4 ]

     CharacterArray fromUTF8Bytes:#[ 16rE6 16r97 16rA5 16rE6 16r9C 16rAC 16rE8 16rAA 16r9E ]

   invalid:

     CharacterArray fromUTF8Bytes:#[ 16rC0 16r80 ]

     CharacterArray fromUTF8Bytes:#[ 16rE0 16r80 16r80 ]

    "

! !

!CharacterArray class methodsFor:'pattern matching'!

matchEscapeCharacter

    "return the character used to escape a matchCharacter

     (i.e. make it a regular character in a matchPattern)"

    ^ $\

!

matchScan:matchScanArray from:matchStart to:matchStop with:aString from:start to:stop caseSensitive:caseSensitive

    "helper for match; return true if the characters from start to stop in

     aString are matching the scan in matchScan from matchStart to matchStop.

     The matchScan is as created by asMatchScanArray.

     This algorithm is not at all the most efficient;

     for heavy duty pattern matching, an interface (primitive) to the regex

     pattern matching package should be added."

    |matchEntry

     mStart "{ Class: SmallInteger }"

     mStop  "{ Class: SmallInteger }"

     sStart "{ Class: SmallInteger }"

     sStop  "{ Class: SmallInteger }"

     mSize  "{ Class: SmallInteger }"

     sSize  "{ Class: SmallInteger }"

     index  "{ Class: SmallInteger }"

     quickCheck matchLast nextMatchEntry

     checkChar included|

    mStart := matchStart.

    mStop := matchStop.

    sStart := start.

    sStop := stop.

    [

"/ Transcript showCR:('match: ''' , (aString copyFrom:sStart to:sStop) ,

"/                    ''' against:' , (matchScanArray copyFrom:mStart to:mStop) printString).

	mSize := mStop - mStart + 1.

	sSize := sStop - sStart + 1.

	"empty strings match"

	(mSize == 0) ifTrue:[^ (sSize == 0)].

	matchEntry := matchScanArray at:mStart.

	"/ the most common case first:

	(sSize ~~ 0

	and:[(checkChar := (aString at:sStart)) = matchEntry]) ifTrue:[

	    "advance by one and continue"

	    mStart := mStart + 1.

	    sStart := sStart + 1

	] ifFalse:[

	    (matchEntry == #any) ifTrue:[

		"restString empty -> no match"

		(sSize == 0) ifTrue:[^ false].

		"# matches single character"

		((sSize == 1) and:[mSize == 1]) ifTrue:[^ true].

		"advance by one and continue"

		mStart := mStart + 1.

		sStart := sStart + 1

	    ] ifFalse:[

		(matchEntry == #anyString) ifTrue:[

		    "* alone matches anything"

		    (mSize == 1) ifTrue:[^ true].

		    "restString empty & matchString not empty -> no match"

		    (sSize == 0) ifTrue:[^ false].

		    "

		     try to avoid some of the recursion by checking last

		     character and continue with shortened strings if possible

		    "

		    quickCheck := false.

		    (mStop >= mStart) ifTrue:[

			matchLast := matchScanArray at:mStop.

			(matchLast ~~ #anyString) ifTrue:[

			    (matchLast == #any) ifTrue:[

				quickCheck := true

			    ] ifFalse:[

				matchLast == (aString at:sStop) ifTrue:[

				    quickCheck := true

				] ifFalse:[

				    matchLast isString ifTrue:[

					quickCheck := matchLast includes:(aString at:sStop)

				    ]

				]

			    ]

			]

		    ].

		    quickCheck ifTrue:[

			"

			 quickCheck ok, advance from the right

			"

			mStop := mStop - 1.

			sStop := sStop - 1

		    ] ifFalse:[

			"/ no quick check;

			"/ look for the next character(s)

			"/ and try matching there

			"/ (to avoid recursion)

			mStart < mStop ifTrue:[

			    nextMatchEntry := matchScanArray at:mStart+1.

			    nextMatchEntry isCharacter ifTrue:[

				sStart <= sStop ifTrue:[

				    [

					caseSensitive ifTrue:[

					    index := aString indexOf:nextMatchEntry startingAt:sStart

					] ifFalse:[

					    index := aString findFirst:[:c | c asLowercase = nextMatchEntry asLowercase]

							     startingAt:sStart.

					].

					(index == 0 or:[index > sStop]) ifTrue:[

					    ^ false

					].

					(self matchScan:matchScanArray

					      from:(mStart + 1)

					      to:mStop

					      with:aString

					      from:index

					      to:sStop

					      caseSensitive:caseSensitive

					) ifTrue:[

					    ^ true

					].