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RewriteRuleElementStream Class

A generic list of elements tracked in an alternative to be used in a -> rewrite rule. We need to subclass to fill in the next() method, which returns either an AST node wrapped around a token payload or an existing subtree.
Inheritance Hierarchy

Namespace:  Stimulsoft.Data.Expressions.Antlr.Runtime.Tree
Assembly:  Stimulsoft.Data (in Stimulsoft.Data.dll) Version: 2019.3.1.0
Syntax
[SerializableAttribute]
public abstract class RewriteRuleElementStream

The RewriteRuleElementStream type exposes the following members.

Constructors
  NameDescription
Public methodRewriteRuleElementStream(ITreeAdaptor, String)
Initializes a new instance of the RewriteRuleElementStream class
Public methodRewriteRuleElementStream(ITreeAdaptor, String, IList)
Create a stream, but feed off an existing list
Public methodRewriteRuleElementStream(ITreeAdaptor, String, Object)
Create a stream with one element
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Properties
  NameDescription
Public propertyCount
Public propertyDescription
Public propertyHasNext
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Methods
  NameDescription
Public methodAdd
Protected methodDup
When constructing trees, sometimes we need to dup a token or AST subtree. Dup'ing a token means just creating another AST node around it. For trees, you must call the adaptor.dupTree() unless the element is for a tree root; then it must be a node dup.
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodNextCore
Do the work of getting the next element, making sure that it's a tree node or subtree. Deal with the optimization of single- element list versus list of size > 1. Throw an exception if the stream is empty or we're out of elements and size>1. protected so you can override in a subclass if necessary.
Public methodNextTree
Return the next element in the stream. If out of elements, throw an exception unless size()==1. If size is 1, then return elements[0]. Return a duplicate node/subtree if stream is out of elements and size==1. If we've already used the element, dup (dirty bit set).
Public methodReset
Reset the condition of this stream so that it appears we have not consumed any of its elements. Elements themselves are untouched. Once we reset the stream, any future use will need duplicates. Set the dirty bit.
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Protected methodToTree
Ensure stream emits trees; tokens must be converted to AST nodes. AST nodes can be passed through unmolested.
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Fields
  NameDescription
Protected fieldadaptor
Protected fieldcursor
Cursor 0..n-1. If singleElement!=null, cursor is 0 until you next(), which bumps it to 1 meaning no more elements.
Protected fielddirty
Once a node / subtree has been used in a stream, it must be dup'd from then on. Streams are reset after subrules so that the streams can be reused in future subrules. So, reset must set a dirty bit. If dirty, then next() always returns a dup.
Protected fieldelementDescription
The element or stream description; usually has name of the token or rule reference that this list tracks. Can include rulename too, but the exception would track that info.
Protected fieldelements
The list of tokens or subtrees we are tracking
Protected fieldsingleElement
Track single elements w/o creating a list. Upon 2nd add, alloc list
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Remarks
Once you start next()ing, do not try to add more elements. It will break the cursor tracking I believe. TODO: add mechanism to detect/puke on modification after reading from stream
See Also