Package com.saxonica.ee.stream.feed

This package contains classes used to support streaming.

See: Description

Interface Summary

Interface	Description
Feed	A Feed is a processing object that sits on a push pipeline to evaluate some expression.
FeedMaker	An expression that can be evaluated in streaming mode is represented at compile time by a list of FeedMaker objects.
FilteringFeed.Filter	Interface defining the filter function, to be implemented by the caller

Class Summary

Class	Description
AbsorptionFeed	This class is used as an abstract superclass for expressions where the consuming operand is absorbed by the expression: for example, data(), string(), or copy-of().
AbsorptionFeed.PendingItem	A pending item represents a tree under construction.
ApplyTemplatesFeed	This class is used when a streaming template applies xsl:apply-templates to composed items, typically to the items in the current group established using xsl:for-each-group
BufferingFeed	A BufferingFeed is used to wrap an expression that does not have intrinsic capability to accept streamed input.
BufferingFilterExpressionFeed	This class is used when a streaming template requests filtering of items that don't come directly from the streamed document, but rather are constructed in the course of the push pipeline
CallableFeed	A CallableFeed is used to wrap an expression that does (a) not have intrinsic capability to accept streamed input, and (b) does not expect any operand to be a sequence, and (c) implements the Callable interface.
CardinalityCheckingFeed	A Feed to go on the streaming pipeline that checks the cardinality of the sequence represented by the events passing down the pipeline.
ComplexNodeEventFeed	This event feed supports instructions that create a document or element node.
CopyOfFeed	This class is used when optimizing a streaming copy, that is, when evaluating a construct of the form saxon:stream(doc('a.xml')/a/b/c).
DecomposingFeed	Appends the output of an ItemFeed to a SequenceReceiver
ElementCreatorFeed	This event feed supports instructions that create a document or element node.
EmptiableElementFeed	This event feed supports instructions that create an element node with an on-empty fallback.
FilteringFeed	This class selects a subset of the items, nodes, or events selected by some supplying expression.
GeneralComparisonFeed	This class is used when a streaming template requests a general comparison with one operand being pushed from the streamed input document, and the other being evaluated in pull mode.
ItemCheckingFeed	A Feed to go on the streaming pipeline that checks the item type of the items in the sequence represented by the events passing down the pipeline.
ItemFeed	An ItemFeed evaluates an expression in "composed push" mode.
ItemMappingFeed	A Feed which applies an ItemMappingFunction to each supplied item.
MotionlessFeed	A feed for an expression that typically accesses the context item but does not consume the input stream
NextIterationFeed	This class is used when one of the xsl:with-param elements within an xsl:next-iteration of an xsl:iterate consumes the streamed input
NoOpenOrCloseFeed	This feed is used for the inner loop of a for-each, where the results of multiple iterations need to be concatenated into a single sequence.
ShallowCopyEventFeed	This event feed implements an implicit xsl:copy instruction used in a built-in template.
SimpleContentFeed	This class is used when a streaming template requests evaluation of a simple content constructor in streaming mode (that is, when it constructs a text, attribute, comment, or PI node based on the contents of the streamed document).
SimpleNodeConstructorFeed	This class is used when a streaming template requests evaluation of a simple content constructor in streaming mode (that is, when it constructs a text, attribute, comment, or PI node based on the contents of the streamed document).
SnapshotFeed	This class provides streamed implementation of the snapshot() function
StringValueFeed	This class is used when a streamed template requests evaluation of the string value of the nodes selected by a path expression, typically in response to an xsl:value-of instruction.
StringValueGatherer	A StringValueAccumulator is a Receiver that computes the string value of an element in streaming mode, by copying all the text nodes to a supplied receiver.
TypedValueFeed	This class is used when a streamed template requests evaluation of the typed value of the nodes selected by a path expression.
WithParamFeed	A WithParamFeed is used to handle a WithParam element (for example, in xsl:next-iteration) whose select expression is evaluated in push mode.

Package com.saxonica.ee.stream.feed Description

This package contains classes used to support streaming. For many kinds of expression that support streaming, there is a Feedclass in this package that evaluates the expression in composed push mode, one item at a time.

None of these classes will be used directly by typical user applications.

These classes generally implement the interface com.saxonica.stream.feed.ItemFeed, whose main methods are open(), append(item), and close(). These methods are called to supply the sequence of items representing the streamed operand of the expression. The feed class can either deliver the result incrementally during calls of the append(item) method, or it can deliver the entire result during the close() method. (It is the responsibility of the class, however, to minimize the amount of data that it buffers).

The Feed class for evaluating an expression is created by calling the FeedMaker, which in turn is returned by the streaming adjunct class for the particular kind of expression.