"{ Package: 'stx:goodies/petitparser/devtools' }"

Object subclass:#XBGFParser

	instanceVariableNames:'productions'

	classVariableNames:''

	poolDictionaries:''

	category:'PetitParser-Utils'

!

!XBGFParser class methodsFor:'documentation'!

documentation

"

    A parse to parse XBGF grammar definitions

    [author:]

        Jan Vrany <jan.vrany@fit.cvut.cz>

    [instance variables:]

    [class variables:]

    [see also:]

        http://slps.github.com/

"

! !

!XBGFParser methodsFor:'accessing'!

productionAt: id

    productions isNil ifTrue:[productions := Dictionary new].

    ^productions at: id ifAbsentPut:[PPUnresolvedParser named: id]

    "Created: / 10-01-2013 / 12:03:02 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!XBGFParser methodsFor:'parsing'!

parse: aStringOrStreamOrFilename

    | doc |

    doc := XML::XMLParser 

                processDocumentStream:aStringOrStreamOrFilename readStream

                beforeScanDo:[:p|p validate: false]. 

    self processDocument: doc.

    ^self

    "Created: / 10-01-2013 / 12:00:01 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!XBGFParser methodsFor:'processing'!

processDocument: doc

    ( doc root / 'ns0:production' ) do:[:node|

        self processProduction: node

    ]

    "Created: / 10-01-2013 / 12:01:26 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

processExpression: node

    | expr parser |

    self assert: node children size == 1.

    expr := node children anElement.

    expr tag type = 'nonterminal' ifTrue:[

        ^self productionAt: expr characterData. 

    ].

    expr tag type = 'terminal' ifTrue:[

        ^PPLiteralSequenceParser on: expr characterData. 

    ].

    expr tag type = 'optional' ifTrue:[

        ^PPOptionalParser on: (self processExpression: (expr / 'ns0:expression') anElement)  

    ].

    expr tag type = 'any' ifTrue:[

        ^#any asParser  

    ].

    expr tag type = 'epsilon' ifTrue:[

        ^nil asParser  

    ].

    expr tag type = 'sequence' ifTrue:[

        parser := PPSequenceParser new

    ] ifFalse:[expr tag type = 'choice' ifTrue:[

        parser := PPChoiceParser new

    ] ifFalse:[expr tag type = 'star' ifTrue:[

        parser := PPRepeatingParser new setMin: 0 max: SmallInteger maxVal.

        parser setParser: (self processExpression: (expr / 'ns0:expression') anElement).

        ^parser

    ] ifFalse:[expr tag type = 'plus' ifTrue:[

        parser := PPRepeatingParser new setMin: 1 max: SmallInteger maxVal.

        parser setParser: (self processExpression: (expr / 'ns0:expression') anElement).

        ^parser

    ] ifFalse:[

        self error: 'Unknown expression: ', expr tag type

    ]]]].

    parser setParsers:

        ((expr / 'ns0:expression') collect:[:e|self processExpression: e]).

    ^parser

    "Created: / 10-01-2013 / 12:05:24 / Jan Vrany <jan.vrany@fit.cvut.cz>"

!

processProduction: node

    | name prod |

    name := (node / 'nonterminal') characterData.

    prod := self productionAt: name.

    self assert: (node / 'ns0:expression') size == 1.

    prod def: (self processExpression: (node / 'ns0:expression') anElement)

    "Created: / 10-01-2013 / 12:01:26 / Jan Vrany <jan.vrany@fit.cvut.cz>"

! !

!XBGFParser class methodsFor:'documentation'!

version

    ^ '$Header: /cvs/stx/stx/goodies/petitparser/devtools/XBGFParser.st,v 1.1 2013-01-10 12:29:16 vrany Exp $'

!

version_CVS

    ^ '$Header: /cvs/stx/stx/goodies/petitparser/devtools/XBGFParser.st,v 1.1 2013-01-10 12:29:16 vrany Exp $'

! !