38 lines
777 B
Smalltalk
38 lines
777 B
Smalltalk
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"
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I return failure, if the delegate parser did not consumed any input.
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"
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Class {
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#name : 'PPNonEmptyParser',
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#superclass : 'PPDelegateParser',
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#category : 'PetitIslands-Parsers'
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}
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{ #category : '*petitislands' }
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PPNonEmptyParser >> acceptsEpsilon [
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^ false
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]
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{ #category : 'analysis' }
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PPNonEmptyParser >> isNullable [
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^ false
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]
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{ #category : 'parsing' }
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PPNonEmptyParser >> nonEmpty [
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^ self
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]
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{ #category : 'parsing' }
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PPNonEmptyParser >> parseOn: aPPContext [
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| memento result |
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memento := aPPContext remember.
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result := parser parseOn: aPPContext.
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((memento position == aPPContext position) and: [ result isPetitFailure not ]) ifTrue: [
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aPPContext restore: memento.
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^ PPFailure message: 'Epsilon parse not allowed' context: aPPContext
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].
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^ result
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]
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