TextDocumentSnapshotScanner Overview (Syntax Parsing Engine)

Topic Overview

Purpose

This topic provides an overview of the TextDocumentSnapshotScanner object’s properties and methods.

In this topic

This topic contains the following sections:

Introduction to TextDocumentSnapshotScanner
- Summary
TextDocumentSnapshotScanner Properties
- Property List
TextDocumentSnapshotScanner Methods
- Method List
Related Content
- Topics

Introduction to TextDocumentSnapshotScanner

Summary

Created via the snapshot’s CreateScanner method the TextDocumentSnapshotScanner class targets a specific instance of a TextDocumentSnaphot and is useful for efficiently scanning through the snapshot’s lines, tokens and words.

Note

Even though the snapshot that it targets is thread safe, the scanner is not. Therefore, create the scanner on the same thread using it (namely, each thread accessing a scanner should create its own). Trying to access the properties and methods of a scanner created on another thread will raise an InvalidOperationException.

Also note that the TextDocumentSnapshotScanner class implements IDisposable and should be used inside of a ‘using’ block or explicitly disposed.

TextDocumentSnapshotScanner Properties

Property List

Property Description

CurrentOffset

This represents the current position of the scanner. When first creating the scanner, the initial property is set to zero. It can be explicitly set, or manipulated by calling any of the ‘SeekTo’ methods in the Methods List table below.

CurrentCharacter

Returns the character at the CurrentOffset

CurrentLine

Returns the line that contains the CurrentOffset.

CurrentToken

Returns the token that contains the CurrentOffset.

Note	Note Setting the `CurrentOffset` to the snapshot’s Length causes the special EOS (end of stream) token to return.

CurrentWord

Returns the word that contains the CurrentOffset`,` or null if the CurrentOffset is not within a word

Snapshot

Returns the associated TextDocumentSnapshot. (read-only)

TextDocumentSnapshotScanner Methods

Method List

Method	Description
PeekNextToken	This method returns the next token without changing the `CurrentOffset`. Use this method’s optional filter (Func<Token, bool>) parameter to skip over tokens that are unimportant (for example,. whitespace, comments or new lines).
PeekPreviousToken	This method returns the previous token without changing the `CurrentOffset`. Use this method’s optional filter (Func<Token, bool>) to skip over tokens that are not important (for example, whitespace, comments or new lines).
PeekNextWord	This method returns the next word without changing the `CurrentOffset`.
PeekPreviousWord	This method returns the previous word without changing the `CurrentOffset`.
SeekToEnd	This method moves the `CurrentOffset` to the end of the document.
SeekToLine	This method moves the `CurrentOffset` to a specific line in the document.
SeekToStart	This method moves the `CurrentOffset` to the start of the document.
SeekToToken	This method moves the `CurrentOffset` to a specific token in the document.
SeekToWord	This method moves the `CurrentOffset` to a specific word in the document.
LineFromOffset	This method retrieves a `SnapshotLineInfo` object for the line of text containing the character at the specified offset.
TokenFromOffset	This method retrieves the `Token` object containing the character at the specified offset.
WordFromOffset	This method retrieves the `Word` object containing the character at the specified offset.

Topic	Purpose
TextDocument Overview	This topic describes the Infragistics Syntax Parsing Engine’s main class, `TextDocument`, and contains links to topics outlining its most important methods, events and properties.
TextDocumentSnapshot Overview	This topic provides an overview of the `TextDocumentSnapshot` object’s properties and methods.

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