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

     2 

     3 PPChoiceParser subclass:#PPLimitedChoiceParser

     4 	instanceVariableNames:'limit'

     5 	classVariableNames:''

     6 	poolDictionaries:''

     7 	category:'PetitParser-Parsers'

     8 !

     9 

    10 !PPLimitedChoiceParser methodsFor:'accessing'!

    11 

    12 limit

    13 	

    14 	^ limit

    15 !

    16 

    17 limit: anObject

    18 	

    19 	limit := anObject

    20 ! !

    21 

    22 !PPLimitedChoiceParser methodsFor:'as yet unclassified'!

    23 

    24 // aRule 

    25 	^ self copyWith: aRule

    26 !

    27 

    28 initialize

    29 	limit := nil asParser

    30 !

    31 

    32 parseOn: aPPContext

    33 	"This is optimized code that avoids unnecessary block activations, do not change. When all choices fail, the last failure is answered."

    34 

    35 	| element limitResult memento |

    36 	"self halt."

    37 	1 to: parsers size do: [ :index |

    38 		memento := aPPContext remember.

    39 		

    40 		element := (parsers at: index)

    41 			parseOn: aPPContext.

    42 		

    43 		(element isPetitFailure not) ifTrue: [ 

    44 			"check limit"

    45 			limitResult := limit parseOn: aPPContext.

    46 			limitResult isPetitFailure ifTrue: [ 

    47 				element := PPFailure message: 'limit failed' at: aPPContext position .

    48 				aPPContext restore: memento.

    49 			] ifFalse: [ ^ element ].

    50 		].

    51 	].	

    52 	^ element

    53 ! !

    54