Class: ActorStream

• Inheritance
• Description
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • converting
  • defining actions
  • queries
  • reading
  • writing

Inheritance:

   Object
   |
   +--Stream
      |
      +--PeekableStream
         |
         +--ActorStream

Package:

stx:libbasic2

Category:

Streams

Version:

rev: 1.25 date: 2021/01/20 13:03:30

user: cg

file: ActorStream.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

This class provides a hook for general objects to behave like Stream objects.
To the outside, actorStreams behave like streams and respond to the
usual stream messages (i.e. nextPut:, nextPutAll: etc).
In the inside, for every nextPut-message, the nextPutBlock is evaluated
passing the argument of nextPut: as block argument.

These blocks are to be provided by the user of the ActorStream.
Example use is in the Transcript, which is made Stream-like this way.

[Instance variables:]
    nextPutBlock    <Block>   the block to evaluate for nextPut:-messages
    nextPutAllBlock <Block>   same for nextPutAll:-messages
    nextBlock       <Block>   the Block to evaluate for the next element

copyright
COPYRIGHT (c) 1989 by Claus Gittinger
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

example
|s i|

i := 0.
s := ActorStream new.
s contentsSpecies:OrderedCollection.
s nextBlock:[i := i + 1. i].
s next.
s next:10.

Class protocol:

 new

have to re-allow new - it was disabled in Stream

Instance protocol:

 contentsSpecies

return a class of which instances will be returned, when
parts of the collection are asked for.
(see upTo-kind of methods in Stream)

 contentsSpecies: aCollectionClass

 readStream

return a readStream from the receiver.
Since this is (hopefully) already a readStream, return self.

 atEndBlock: aBlock

define the block to be evaluated for every atEnd-message

 nextBlock: aBlock

define the block to be evaluated for every next-message

 nextPutAllBlock: aBlock

define the block to be evaluated for every nextPutAll-message.
If undefined, nextPuts will be used (as inherited)

 nextPutBlock: aBlock

define the block to be evaluated for every nextPut-message

 nextPutLineBlock: aBlock

define the block to be evaluated for every nextPutLineBlock-message.
If undefined, nextPutAll/nextPut will be used (as inherited)

 peekBlock: aBlock

define the block to be evaluated for every peek-message

 atEnd

return true, if at the end - actorStreams are never

 next

return the next element from the stream by evaluating the nextBlock

 peek

peek ahead for return the next element from the stream by evaluating the peekBlock

 flush

any buffered, but not yet written partial line?
This only happens if the actorStream has only a nextPutLine action,
but no nextPutAll/nextPut action,
and no linefeed appeared.
Useful to ensure that any remaining data is processed.

 nextPut: aCharacter

put aCharacter onto the stream by evaluating the nextPutBlock with aCharacter as argument.
Answer anObject

 nextPutAll: something

put all elements of something onto the stream by evaluating
the nextPutAllBlock with something as argument.
If there is no nextPutAllBlock, nextPuts will be used (as inherited).
Answer the receiver.

 nextPutAll: count from: buffer startingAt: start

put some elements of something onto the stream by evaluating
the nextPutAllBlock with something as argument.
If there is no nextPutAllBlock, individual nextPuts will be used (as inherited).
Answer the number of elements that were appended.

 nextPutAll: something startingAt: start to: stop

put some elements of something onto the stream by evaluating
the nextPutAllBlock with something as argument.
If there is no nextPutAllBlock, nextPuts will be used (as inherited)

 nextPutByte: something

put something onto the stream by evaluating the nextPutBlock with
something as argument

 nextPutLine: something

put the line onto the stream by evaluating
the nextPutLineBlock with something as argument.
If there is no nextPutLineBlock, nextPutAll/nextPut will be used (as inherited)