Class: ReadWriteStream

• Inheritance
• Description
• Instance protocol
  • access-reading
  • accessing
  • converting
  • initialization
  • queries
• Examples

Inheritance:

   Object
   |
   +--Stream
      |
      +--PeekableStream
         |
         +--PositionableStream
            |
            +--WriteStream
               |
               +--ReadWriteStream
                  |
                  +--ExternalStream

Package:

stx:libbasic

Category:

Streams

Version:

rev: 1.30 date: 2009/07/08 18:01:50

user: stefan

file: ReadWriteStream.st directory: libbasic

module: stx stc-classLibrary: libbasic

Author:

Claus Gittinger

Description:

ReadWriteStreams allow both read- and write-access to some collection.
To allow this, they reenable some methods blocked in WriteStream.
(being one of the seldom places, where multiple inheritance could be
 of good use in smalltalk).

Claus:
    I personally find the ReadStream - WriteStream - ReadWriteStream
    organization brain-damaged. It would be better to have an attribute
    (such as readOnly / writeOnly / readWrite) in an InternalStream subclass 
    of Stream ...

Instance protocol:

 next

return the next element; advance read position.
If there are no more elements, nil is returned.

 nextByte

return the next element; advance read pointer.
return nil, if there is no next element

 peek

return the element to be read next without advancing read position.
If there are no more elements, nil is returned.

 contents

return the contents as written so far;
redefined to prevent confusion resulting due to
my superclasses optimization. (see WriteStream contents).
ST80 users if RWStream expect the contents array to remain
unchanged.

 reset

set the read position to the beginning of the collection

 readStream

return the receiver as a readStream - thats myself

 readStreamOrNil

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

This method has been defined for protocol copmatibility with Filename

 with: initialCollection

redefined from WriteStream, to position to the beginning of the stream

 isReadable

return true if the receiver supports reading - thats true

 size

return the number of elements in the streamed collection.

Examples: