Hierarchy

Implemented by

Index

Properties

IIntStream

IIntStream: Interface<IIntStream> = new Stimulsoft.System.Interface<IIntStream>("IIntStream")

A simple stream of integers used when all I care about is the char or token type sequence (such as interpretation).

count

count: number

Only makes sense for streams that buffer everything up probably, but might be useful to display the entire stream or for testing. This value includes a single EOF.

index

index: number

Return the current input symbol index 0..n where n indicates the last symbol has been read. The index is the symbol about to be read not the most recently read symbol.

sourceName

sourceName: string

Where are you getting symbols from? Normally, implementations will pass the buck all the way to the lexer who can ask its input stream for the file name or whatever.

tokenStream

tokenStream: ITokenStream

If the tree associated with this stream was created from a {@link TokenStream}, you can specify it here. Used to do rule {@code $text} attribute in tree parser. Optional unless you use tree parser rule {@code $text} attribute or {@code output=template} and {@code rewrite=true} options.

treeAdaptor

treeAdaptor: ITreeAdaptor

What adaptor can tell me how to interpret/navigate nodes and trees. E.g., get text of a node.

treeSource

treeSource: any

Where is this stream pulling nodes from? This is not the name, but the object that provides node objects.

uniqueNavigationNodes

uniqueNavigationNodes: boolean

As we flatten the tree, we use {@link Token#UP}, {@link Token#DOWN} nodes to represent the tree structure. When debugging we need unique nodes so we have to instantiate new ones. When doing normal tree parsing, it's slow and a waste of memory to create unique navigation nodes. Default should be {@code false}.

Methods

consume

  • consume(): any

get

  • Get a tree node at an absolute index i; 0..n-1. If you don't want to buffer up nodes, then this method makes no sense for you.

    Parameters

    • i: number

    Returns ITreeNodeStream

la

  • la(i: number): number
  • Get int at current input pointer + i ahead where i=1 is next int. Negative indexes are allowed. LA(-1) is previous token (token just matched). LA(-i) where i is before first token should yield -1, invalid char / EOF.

    Parameters

    • i: number

    Returns number

lt

  • lt(k: number): any
  • Get tree node at current input pointer + ahead where ==1 is next node. <0 indicates nodes in the past. So {@code LT(-1)} is previous node, but implementations are not required to provide results for < -1. {@code LT(0)} is undefined. For <=n, return . Return for {@code LT(0)} and any index that results in an absolute address that is negative.

    This is analogous to , but this returns a tree node instead of a . Makes code generation identical for both parser and tree grammars.

    Parameters

    • k: number

    Returns any

mark

  • mark(): number
  • Tell the stream to start buffering if it hasn't already. Return current input position, Index, or some other marker so that when passed to rewind() you get back to the same spot. rewind(mark()) should not affect the input cursor. The Lexer track line/col info as well as input index so its markers are not pure input indexes. Same for tree node streams.

    Returns number

release

  • release(marker: number): any
  • You may want to commit to a backtrack but don't want to force the stream to keep bookkeeping objects around for a marker that is no longer necessary. This will have the same behavior as rewind() except it releases resources without the backward seek. This must throw away resources for all markers back to the marker argument. So if you're nested 5 levels of mark(), and then release(2) you have to release resources for depths 2..5.

    Parameters

    • marker: number

    Returns any

replaceChildren

  • replaceChildren(parent: any, startChildIndex: number, stopChildIndex: number, t: any): any
  • Replace children of {@code parent} from index {@code startChildIndex} to {@code stopChildIndex} with {@code t}, which might be a list. Number of children may be different after this call. The stream is notified because it is walking the tree and might need to know you are monkeying with the underlying tree. Also, it might be able to modify the node stream to avoid restreaming for future phases.

    If {@code parent} is {@code null}, don't do anything; must be at root of overall tree. Can't replace whatever points to the parent externally. Do nothing.

    Parameters

    • parent: any
    • startChildIndex: number
    • stopChildIndex: number
    • t: any

    Returns any

rewind

  • rewind(marker?: number): any
  • Reset the stream so that next call to index would return marker. The marker will usually be Index but it doesn't have to be. It's just a marker to indicate what state the stream was in. This is essentially calling release() and seek(). If there are markers created after this marker argument, this routine must unroll them like a stack. Assume the state the stream was in when this marker was created.

    Parameters

    • Optional marker: number

    Returns any

seek

  • seek(index: number): any
  • Set the input cursor to the position indicated by index. This is normally used to seek ahead in the input stream. No buffering is required to do this unless you know your stream will use seek to move backwards such as when backtracking.

    This is different from rewind in its multi-directional requirement and in that its argument is strictly an input cursor (index).

    For char streams, seeking forward must update the stream state such as line number. For seeking backwards, you will be presumably backtracking using the mark/rewind mechanism that restores state and so this method does not need to update state when seeking backwards.

    Currently, this method is only used for efficient backtracking using memoization, but in the future it may be used for incremental parsing.

    The index is 0..n-1. A seek to position i means that LA(1) will return the ith symbol. So, seeking to 0 means LA(1) will return the first element in the stream.

    Parameters

    • index: number

    Returns any

toString

  • toString(start: any, stop: any): string
  • Return the text of all nodes from {@code start} to {@code stop}, inclusive. If the stream does not buffer all the nodes then it can still walk recursively from start until stop. You can always return {@code null} or {@code ""} too, but users should not access {@code $ruleLabel.text} in an action of course in that case.

    Parameters

    • start: any
    • stop: any

    Returns string

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