1 "{ Package: 'squeak:petitparser' }"

     2 

     3 ReadStream subclass:#PPStream

     4 	instanceVariableNames:''

     5 	classVariableNames:''

     6 	poolDictionaries:''

     7 	category:'PetitParser-Core'

     8 !

     9 

    10 PPStream comment:'A positional stream implementation used for parsing. It overrides some methods for optimization reasons.'

    11 !

    12 

    13 

    14 !PPStream methodsFor:'accessing'!

    15 

    16 next: anInteger 

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

    18 

    19 	| answer endPosition |

    20 	endPosition := position + anInteger min: readLimit.

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

    22 	position := endPosition.

    23 	^ answer

    24 !

    25 

    26 peek

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

    28 

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

    30 !

    31 

    32 position: anInteger

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

    34 

    35 	position := anInteger

    36 !

    37 

    38 uncheckedPeek

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

    40 

    41 	^ collection at: position + 1

    42 ! !

    43 

    44 !PPStream methodsFor:'converting'!

    45 

    46 asPetitStream

    47 	^ self

    48 ! !

    49 

    50 !PPStream methodsFor:'printing'!

    51 

    52 printOn: aStream

    53 	collection isString

    54 		ifFalse: [ ^ super printOn: aStream ].

    55 	aStream

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

    57 		nextPutAll: '·';

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

    59 ! !

    60 

    61 !PPStream class methodsFor:'documentation'!

    62 

    63 version_SVN

    64     ^ '$Id: PPStream.st,v 1.1 2011-08-18 18:56:17 cg Exp $'

    65 ! !