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TextRewriter class

The abstract base class for operations that can be applied by TextRewriterTransform .

Signature:
export declare abstract class TextRewriter 

Remarks

The TextRewriterTransform applies one or more character rewriting operations to its chunk stream. Since these operations are applied separately to stderr and stdout , the state is stored in an opaque TextRewriterState object.

Conceptually, a TextRewriter subclass is very similar to a regular expression, with the difference that RegExp operates on a text string, whereas TextRewriter operates on a stream of characters.

The two most common subclasses are NormalizeNewlinesTextRewriter and RemoveColorsTextRewriter .

A rewriting operation starts with initialize() , followed by any number of process() calls, and then finishes with close() . For example:

const rewriter: NormalizeNewlinesTextRewriter = new NormalizeNewlinesTextRewriter(NewlineKind.Lf);
const state: TextRewriterState = rewriter.initialize();
let output: string = rewriter.process(state, 'line 1\r');
output += rewriter.process(state, '\nline 2\r\n');
output += rewriter.close(state);

// The final "output" value is: "line 1\nline 2\n"

After close() has been called, the TextRewriterState state should not be reused.

Methods

MethodModifiersDescription
close(state)Close the TextRewriterState object and return any buffered output.
initialize()Create a new TextRewriterState object that can be used to process a stream of characters.
process(state, input)Rewrite the next sequence of characters from the input stream, returning the modified output.