"

 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.

"

Object subclass:#Scanner

	instanceVariableNames:'source lineNr collectedSource token tokenType tokenPosition

		tokenValue tokenName tokenLineNr tokenRadix hereChar peekChar

		peekChar2 requestor exitBlock errorFlag ignoreErrors

		ignoreWarnings saveComments currentComments warnSTXSpecialComment

		warnUnderscoreInIdentifier warnOldStyleAssignment

		warnCommonMistakes outStream outCol warnSTXNameSpaceUse'

	classVariableNames:'TypeArray ActionArray AllowUnderscoreInIdentifier Warnings

		WarnSTXSpecials WarnOldStyleAssignment WarnUnderscoreInIdentifier

		WarnCommonMistakes'

	poolDictionaries:''

	category:'System-Compiler'

!

!Scanner 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

"

    Scanner reads from a stream and returns individual smalltalk tokens

    TODO: some testers noticed, that ST-80's scanner methods are called

    xLetter, xDigit etc. For code using these (internals), the nextNumber,

    nextIdentifier etc. methods should be renamed.

    (to me, these seem to be internal private methods; their public use

     is not a good idea ..)

"

! !

!Scanner class methodsFor:'initialization'!

initialize

    Warnings := true.

    WarnSTXSpecials := true.

    WarnUnderscoreInIdentifier := true.

    WarnOldStyleAssignment := true.

    WarnCommonMistakes := true.

    AllowUnderscoreInIdentifier := false.

!

setupActions

    |block|

    ActionArray := Array new:256.

    TypeArray := Array new:256.

    block := [:s :char | s nextNumber].

    ($0 asciiValue) to:($9 asciiValue) do:[:index |

	ActionArray at:index put:block

    ].

    block := [:s :char | s nextSpecial].

    #( $& $- $+ $= $* $/ $\ $< $> $~ $@ $, $? "new:" $!! ) do:[:binop |

	TypeArray at:(binop asciiValue) put:#special.

	ActionArray at:(binop asciiValue) put:block

    ].

    block := [:s :char | s nextToken:char].

    #( $; $. $( $) $[ $] "$!!" $^ $| $_ ) do:[:ch |

	ActionArray at:(ch asciiValue) put:block

    ].

    block := [:s :char | s nextIdentifier].

    ($a asciiValue) to:($z asciiValue) do:[:index |

	ActionArray at:index put:block

    ].

    ($A asciiValue) to:($Z asciiValue) do:[:index |

	ActionArray at:index put:block

    ].

    AllowUnderscoreInIdentifier ifTrue:[

	ActionArray at:$_ asciiValue put:block

    ].

    "kludge: action is characterToken, but type is special"

    TypeArray at:($| asciiValue) put:#special.

    "kludge: action is nextColonOrAssign, but type is special"

    TypeArray at:($: asciiValue) put:#special.

    ActionArray at:($' asciiValue) put:[:s :char | s nextString].

    ActionArray at:($$ asciiValue) put:[:s :char | s nextCharacter].

    ActionArray at:($# asciiValue) put:[:s :char | s nextHash].

    ActionArray at:($% asciiValue) put:[:s :char | s nextPrimitive].

    ActionArray at:($: asciiValue) put:[:s :char | s nextColonOrAssign]

    "

     Scanner setupActions

    "

! !

!Scanner class methodsFor:'instance creation'!

for:aStringOrStream

    "return a new scanner reading from aStringOrStream"

    ^ (super new) initializeFor:aStringOrStream

! !

!Scanner class methodsFor:'defaults'!

allowUnderscoreInIdentifier

    "return true, if underscores are allowed in identifiers"

    ^ AllowUnderscoreInIdentifier

!

allowUnderscoreInIdentifier:aBoolean

    "this allows turning on/off underscores in identifiers.

     If turned off (the default), underscores are not allowed in identifiers,

     but instead scanned as assignment character (old ST/80 syntax).

     If turned on, underscores are in identifiers are allowed, while extra

     underscores are still scanned as assignment.

     If you have to fileIn VV-Vsn2 classes, 

     add a line such as:

	Compiler allowUnderscoreInIdentifiers:false

     in your 'private.rc'/'smalltalk.rc' file"

    AllowUnderscoreInIdentifier := aBoolean.

    self setupActions

!

warnCommonMistakes

    "return true, if common beginners mistakes are to be warned about"

    ^ WarnCommonMistakes

!

warnCommonMistakes:aBoolean

    "this allows turning on/off warnings about common beginners mistakes.

     Those are not really errors in the strict sense, but often lead to

     run time errors later.

     Examples are: expr or:expr2, where expr2 is not a block.

     If you get bored by those warnings, turn them off by adding

     a line as:

	Compiler warnCommonMistakes:false

     in your 'private.rc' file"

    WarnCommonMistakes := aBoolean

!

warnOldStyleAssignment

    "return true, if underscore-assignment (pre ST-80v4 syntax) are to be warned about"

    ^ WarnOldStyleAssignment

!

warnOldStyleAssignment:aBoolean

    "this allows turning on/off warnings about underscore-assignment (pre ST-80v4 syntax).

     If you get bored by those warnings, turn them off by adding

     a line as:

	Compiler warnOldStyleAssignment:false

     in your 'private.rc' file"

    WarnOldStyleAssignment := aBoolean

!

warnSTXSpecials

    "return true, if ST/X specials are to be warned about"

    ^ WarnSTXSpecials

!

warnSTXSpecials:aBoolean

    "this allows turning on/off warnings about stx specials.

     If you get bored by those warnings, turn them off by adding

     a line as:

	Compiler warnSTXSpecials:false

     in your 'private.rc' file"

    WarnSTXSpecials := aBoolean

!

warnUnderscoreInIdentifier

    "return true, if underscores in identifiers are to be warned about"

    ^ WarnUnderscoreInIdentifier

!

warnUnderscoreInIdentifier:aBoolean

    "this allows turning on/off warnings about underscores in identifiers.

     If you get bored by those warnings, turn them off by adding

     a line as:

	Compiler warnUnderscoreInIdentifier:false

     in your 'private.rc' file"

    WarnUnderscoreInIdentifier := aBoolean

!

warnings

    "return true, if any warnings are to be shown"

    ^ Warnings

!

warnings:aBoolean

    "this allows turning on/off warnings; the default is on.

     You can turn off warnings in your 'private.rc' file with

	 Compiler warnings:false

    "

    Warnings := aBoolean

! !

!Scanner methodsFor:'ST-80 compatibility'!

endOfLastToken

    ^ source position

! !

!Scanner methodsFor:'accessing'!

comments

    ^ currentComments

    "Created: 20.4.1996 / 20:07:01 / cg"

!

saveComments:aBoolean

    saveComments := aBoolean

    "Created: 20.4.1996 / 20:03:56 / cg"

!

sourceStream

    ^ source

    "Created: 20.4.1996 / 19:59:58 / cg"

! !

!Scanner methodsFor:'directives'!

parseDirective

    |directive packageName namespace list|

    source next.

    source skipSeparatorsExceptCR.

    hereChar := source peek.

    hereChar isLetter ifTrue:[

        directive := source nextWord.

        source peek == $: ifTrue:[

            source next.

            source skipSeparatorsExceptCR.

            hereChar := source peek.

            "

             Package: 'name-of-package'

            "

            directive = 'Package' ifTrue:[

                packageName := self parseDirectiveStringArg.

                packageName notNil ifTrue:[

                    (requestor respondsTo:#setPackage:) ifTrue:[

                        requestor setPackage:packageName

                    ].

                ].

            ].

            "

             Namespace: 'name-of-package'

            "

            (directive = 'Namespace' 

            or:[directive = 'NameSpace']) ifTrue:[

                namespace := self parseDirectiveStringArg.

                namespace notNil ifTrue:[

                    (requestor respondsTo:#setNameSpace:) ifTrue:[

                        requestor setNameSpace:namespace 

                    ] ifFalse:[

                        self setNameSpace:namespace

                    ].

                ].

            ].

            "

             Uses: 'nameSpace1', ... , 'nameSpace2'

            "

            directive = 'Uses' ifTrue:[

                list := self parseDirectiveStringListArg.

                (requestor respondsTo:#useNameSpaces:) ifTrue:[

                    requestor useNameSpaces:list 

                ]

            ].

            "

             Prerequisites: 'name-of-package', ... , 'name-of-package'

            "

            directive = 'Prerequisites' ifTrue:[

                list := self parseDirectiveStringListArg.

                (requestor respondsTo:#requirePackages:) ifTrue:[

                    requestor requirePackages:list 

                ].

            ].

        ]

    ].

    hereChar := source peek.

    "Modified: 8.11.1996 / 13:33:18 / cg"

!

parseDirectiveStringArg

    hereChar == $' ifTrue:[

	self nextString.

	tokenType == #String ifTrue:[

	    ^ tokenValue

	]

    ].

    ^ nil

!

parseDirectiveStringListArg

    |list|

    list := OrderedCollection new.

    [hereChar == $'] whileTrue:[

	list addLast:self parseDirectiveStringArg.

	source skipSeparatorsExceptCR.

	hereChar := source peek.

	(hereChar == $,) ifTrue:[

	    source next.

	    source skipSeparatorsExceptCR.

	    hereChar := source peek.

	].

    ].

    ^ list

! !

!Scanner methodsFor:'error handling'!

notifyError:aMessage position:position to:endPos

    "notify requestor of an error - if there is no requestor

     put it on the transcript. Requestor is typically the CodeView

     in which the accept/doIt was triggered, or the PositionableStream

     which does the fileIn. The requestor may decide how to highlight the

     error (and/or to abort the compile).

     Return the result passed back by the requestor."

    ignoreErrors ifFalse:[

	requestor isNil ifTrue:[

	    self showErrorMessage:aMessage position:position.

	    ^ false

	].

	^ requestor error:aMessage position:position to:endPos from:self 

    ].

    ^ false

!

notifyWarning:aMessage position:position to:endPos

    "notify requestor of an warning - if there is no requestor

     put it on the transcript.

     Return the result passed back by the requestor."

    ignoreWarnings ifFalse:[

	requestor isNil ifTrue:[

	    self showErrorMessage:aMessage position:position.

	    ^ false

	].

	^ requestor warning:aMessage position:position to:endPos from:self

    ].

    ^ false

!

showErrorMessage:aMessage position:pos

    "show an errormessage on the Transcript"

    ignoreErrors ifFalse:[

	Smalltalk silentLoading == true ifFalse:[

	    Transcript showCR:(pos printString , ' [line: ' , tokenLineNr printString , '] ' , aMessage)

	]

    ]

    "Modified: 18.5.1996 / 15:44:35 / cg"

!

syntaxError:aMessage

    "a syntax error happened - position is not known"

    ^ self syntaxError:aMessage position:tokenPosition

!

syntaxError:aMessage position:position

    "a syntax error happened - only start position is known"

    ^ self syntaxError:aMessage position:position to:nil

!

syntaxError:aMessage position:position to:endPos

    "a syntax error happened"

    self notifyError:('Error:' , aMessage) position:position to:endPos.

    exitBlock notNil ifTrue:[exitBlock value].

    ^ false

!

warnCommonMistake:msg at:position

    self warnCommonMistake:msg position:position to:position

    "Modified: 18.7.1996 / 10:28:53 / cg"

!

warnCommonMistake:msg position:pos1 to:pos2

    ignoreWarnings ifFalse:[

        warnCommonMistakes ifTrue:[

            self 

                warning:msg

                position:pos1 to:pos2.

        ]

    ]

    "Created: 18.7.1996 / 10:28:38 / cg"

!

warnOldStyleAssignmentAt:position

    ignoreWarnings ifFalse:[

	warnOldStyleAssignment ifTrue:[

	    self 

		warning:'old style assignment - please change to use '':='''

		position:position to:position.

	    "

	     only warn once (per method)

	    "

	    warnOldStyleAssignment := false

	]

    ]

!

warnUnderscoreAt:position

    ignoreWarnings ifFalse:[

	warnUnderscoreInIdentifier ifTrue:[

	    self 

		warning:'underscores in identifiers/symbols are nonportable' 

		position:position to:position.

	    "

	     only warn once (per method)

	    "

	    warnUnderscoreInIdentifier := false

	]

    ]

!

warning:aMessage

    "a warning - position is not known"

    ^ self warning:aMessage position:tokenPosition

!

warning:aMessage position:position

    "a warning - only start position is known"

    ^ self warning:aMessage position:position to:nil

!

warning:aMessage position:position to:endPos

    "a warning"

    ^ self notifyWarning:('Warning: ' , aMessage) position:position to:endPos

! !

!Scanner methodsFor:'general scanning'!

scanPositionsFor:aTokenString inString:aSourceString

    "scan aSourceString for occurrances of aTokenString.