"{ Package: 'stx:libbasic2' }"

Stream subclass:#CollectingReadStream

	instanceVariableNames:'collectBlock inStream'

	classVariableNames:''

	poolDictionaries:''

	category:'Streams'

!

!CollectingReadStream class methodsFor:'documentation'!

documentation

"

    A stream which provides the result of applying a collectBlock

    to the elements of an underlying stream. 

"

!

examples

"

                                                            [exBegin]

    |s|

    s := CollectingReadStream 

            on:#(1 2 3 4 5 6 7 8) readStream

            collecting:[:each | each squared].

    s upToEnd  

                                                            [exEnd]

                                                            [exBegin]

    |s|

    s := (#(1 2 3 4 5 6 7 8) readStream 

            selecting:[:n | n odd])

                collecting:[:n | n squared].

    s upToEnd    

                                                            [exEnd]

"

! !

!CollectingReadStream class methodsFor:'instance creation'!

on:aStream collecting:aBlock

    ^ self basicNew on:aStream collecting:aBlock

! !

!CollectingReadStream methodsFor:'instance creation'!

on:aStream collecting:aBlock

    inStream := aStream.

    collectBlock := aBlock.

! !

!CollectingReadStream methodsFor:'queries'!

atEnd

    ^ inStream atEnd

! !

!CollectingReadStream methodsFor:'reading'!

next

    inStream atEnd ifTrue:[

        ^ self pastEndRead

    ].

    ^ collectBlock value:(inStream next)

! !

!CollectingReadStream class methodsFor:'documentation'!

version_CVS

    ^ '$Header: /cvs/stx/stx/libbasic2/CollectingReadStream.st,v 1.1 2009-12-05 11:15:59 cg Exp $'

! !