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

"{ NameSpace: Smalltalk }"

ReadStream subclass:#PPStream

	instanceVariableNames:'newlines'

	classVariableNames:''

	poolDictionaries:''

	category:'PetitParser-Core'

!

!PPStream methodsFor:'accessing'!

collection

	"Answer the underlying collection."

	^ collection

!

next: anInteger 

	"Answer up to anInteger elements of my collection. Overridden for efficiency."

	| answer endPosition |

	endPosition := position + anInteger min: readLimit.

	answer := collection copyFrom: position + 1 to: endPosition.

	position := endPosition.

	^ answer

!

peek

	"An improved version of peek, that is slightly faster than the built in version."

	^ self atEnd ifFalse: [ collection at: position + 1 ]

!

position: anInteger

	"The receiver does not check for invalid arguments passed to this method, as it is solely used with valid indexes for backtracking."

	position := anInteger

!

size

	"

		The same implementation as a ReadStream. Implemented here for compatibility with Smalltalk/X

		that has different implementation in a ReadStream

	"

	^readLimit

!

uncheckedPeek

	"An unchecked version of peek that throws an error if we try to peek over the end of the stream, even faster than #peek."

	^ collection at: position + 1

! !

!PPStream methodsFor:'converting'!

asPetitStream

	^ self

! !

!PPStream methodsFor:'positioning'!

column: pos

	| nl |

	(pos = -1) ifTrue: [  ^ 0 ].

	(pos > readLimit) ifTrue: [ ^ self error: 'Out of limit' ].

	nl := self newlines.

	nl keysAndValuesDo: [ :index :value |

		(value > pos) ifTrue: [ ^ pos - (nl at: (index - 1)) + 1]

	].	

	^ pos - (nl at: (nl size )) + 1

!

fillNewlines

	| tmp line |

	newlines := OrderedCollection new.	

	tmp := position.

	line := 0.

	(0 to: readLimit) do: [:index |

		position := index.

		self isStartOfLine ifTrue: [ newlines add: position ]

	].

	position := tmp.

	newlines := newlines asArray.

	^ newlines

!

line: pos

	| nl |

	(pos = -1) ifTrue: [  ^ 0 ].

	(pos > readLimit) ifTrue: [ ^ self error: 'Out of limit' ].

	nl := self newlines.

	nl keysAndValuesDo: [ :index :value |

		(value > pos) ifTrue: [ ^ (index - 1)]

	].	

	^ nl size

!

newlines

	^ newlines ifNil: [ 

		newlines := self fillNewlines.

	]

! !

!PPStream methodsFor:'printing'!

printOn: aStream

	collection isString

		ifFalse: [ ^ super printOn: aStream ].

	aStream

		nextPutAll: (collection copyFrom: 1 to: position);

		nextPutAll: '·';

		nextPutAll: (collection copyFrom: position + 1 to: readLimit)

! !

!PPStream methodsFor:'queries'!

column

	^ self column: position.

!

insideCRLF

	(position < 1) ifTrue: [ ^ false ].

	^ (self peek = (Character codePoint: 10)) and: [ self peekBack = (Character codePoint: 13) ]

!

isEndOfLine

	self atEnd ifTrue: [ ^ true ].

	self insideCRLF ifTrue: [ ^ false ].

	^ (self peek = (Character codePoint: 13) or: [ self peek = (Character codePoint: 10)]).

!

isStartOfLine

	(position = 0) ifTrue: [ ^ true ].

	self insideCRLF ifTrue: [ ^ false ].

	^ (self peekBack = (Character codePoint: 13)) or: [ self peekBack = (Character codePoint: 10)].

!

line

	^ self line: position

! !

!PPStream class methodsFor:'documentation'!

version

    ^ '$Header: /cvs/stx/stx/goodies/petitparser/PPStream.st,v 1.4 2014-03-04 14:32:00 cg Exp $'

!

version_CVS

    ^ '$Header: /cvs/stx/stx/goodies/petitparser/PPStream.st,v 1.4 2014-03-04 14:32:00 cg Exp $'

!

version_HG

    ^ '$Changeset: <not expanded> $'

!

version_SVN

    ^ '$Id: PPStream.st,v 1.4 2014-03-04 14:32:00 cg Exp $'

! !