"{ Package: 'stx:goodies/xtreams/substreams' }"

"{ NameSpace: Xtreams }"

PositionReadSubstream subclass:#LimitReadSubstream

	instanceVariableNames:'limit'

	classVariableNames:''

	poolDictionaries:''

	category:'Xtreams-Substreams'

!

LimitReadSubstream comment:'Limits the number of elements that can be read from the source stream.

Instance Variables

	limit   <Integer> maximum number of elements that can be read from this stream

	position        <Integer> number of elements already read from the stream

'

!

!LimitReadSubstream class methodsFor:'instance creation'!

on: aSource limit: anInteger

	^self new on: aSource limit: anInteger

! !

!LimitReadSubstream methodsFor:'accessing'!

get

	position = limit ifTrue: [Incomplete zero raise].

	^super get

!

read: anInteger into: aSequenceableCollection at: startIndex

	| count |

	count := anInteger min: self available.

	super read: count into: aSequenceableCollection at: startIndex.

	count < anInteger ifTrue: [(Incomplete on: aSequenceableCollection count: count at: startIndex) raise].

	^anInteger

! !

!LimitReadSubstream methodsFor:'initialize-release'!

on: aSource limit: anInteger

	self on: aSource.

	limit := anInteger

!

subseekend

	self isPositionable ifFalse: [^self].

	self -= 0

! !

!LimitReadSubstream methodsFor:'seeking'!

-= anInteger

	| available |

	anInteger < 0 ifTrue: [Incomplete zero raise].

	available := anInteger min: limit.

	source ++ (limit - position - available).

	position := limit - available.

	available = anInteger ifTrue: [^anInteger].

	^(Incomplete count: available) raise

!

length

	^limit

! !

!LimitReadSubstream class methodsFor:'documentation'!

version_HG

    ^ '$Changeset: <not expanded> $'

! !