--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PPStream.st	Thu Aug 18 20:56:17 2011 +0200
@@ -0,0 +1,65 @@
+"{ Package: 'squeak:petitparser' }"
+
+ReadStream subclass:#PPStream
+	instanceVariableNames:''
+	classVariableNames:''
+	poolDictionaries:''
+	category:'PetitParser-Core'
+!
+
+PPStream comment:'A positional stream implementation used for parsing. It overrides some methods for optimization reasons.'
+!
+
+
+!PPStream methodsFor:'accessing'!
+
+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
+!
+
+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:'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 class methodsFor:'documentation'!
+
+version_SVN
+    ^ '$Id: PPStream.st,v 1.1 2011-08-18 18:56:17 cg Exp $'
+! !