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

"{ NameSpace: Smalltalk }"

PPCompiledParser subclass:#PPTokenizingCompiledParser
	instanceVariableNames:'currentTokenValue currentTokenType'
	classVariableNames:''
	poolDictionaries:''
	category:'PetitCompiler-Parsers'
!

!PPTokenizingCompiledParser methodsFor:'tokenizing'!

consume: tokenType
    (self currentTokenTypeIs: tokenType) ifTrue: [ 
        | retval |
        retval := currentTokenValue.
        currentTokenType := nil.
        ^ retval
    ] ifFalse: [ 
        "self error: 'expected: ', tokenType storeString, ' got ', currentTokenType storeString."
        self error.
    ]
!

consumeWhitespace
    self shouldBeImplemented 
!

currentTokenType
    currentTokenType isNil ifTrue: [ self nextToken ].
    ^ currentTokenType
!

currentTokenTypeIs: tokenType
    "if the type is read"
    currentTokenType isNil ifFalse: [ ^ currentTokenType = tokenType ].
    
    "if not, try to read the token"
    self perform: tokenType.
    error ifTrue: [  
        ^ error := false.
    ].
    ^ true
!

currentTokenValue
    currentTokenType isNil ifTrue: [ self nextToken ].
    ^ currentTokenType
!

nextToken
    self shouldBeImplemented 
!

parseOn: aPPContext
    | retval |

    context := aPPContext.
    context compiledParser: self.
    failure := PPFailure new message: nil; context: context; position: -1.
    context noteFailure: failure.
    error := false.
    currentTokenType := nil.

    self consumeWhitespace.
    retval := self perform: startSymbol.
    self consumeWhitespace.

    (retval isPetitFailure) ifTrue: [ aPPContext noteFailure: failure ].
    error ifTrue: [ aPPContext noteFailure: failure. retval := failure ].
    
"	aPPContext position: context position."
    ^ retval
! !