Change TextDocument's getText to take an optional range

types/src/main.ts

@@ -1460,11 +1460,14 @@ export interface TextDocument {
 	readonly version: number;
 
 	/**
-	 * Get the text of this document.
+	 * Get the text of this document. A substring can be retrieved by
+	 * providing a range.
 	 *
-	 * @return The text of this document.
+	 * @param range The interested range within the document to return.
+	 * @return The text of this document or a substring of the text if a
+	 *         range is provided.
 	 */
-	getText(): string;
+	getText(range?: Range): string;
 
 	/**
 	 * Converts a zero-based offset to a position.
@@ -1607,7 +1610,12 @@ class FullTextDocument implements TextDocument {
 		return this._version;
 	}
 
-	public getText(): string {
+	public getText(range?: Range): string {
+		if (range) {
+			let start = this.offsetAt(range.start);
+			let end = this.offsetAt(range.end);
+			return this._content.substring(start, end);
+		}
 		return this._content;
 	}
 

types/src/test/textdocument.test.ts

@@ -5,7 +5,7 @@
 'use strict';
 
 import assert = require('assert');
-import { TextDocument, Position } from '../main';
+import { TextDocument, Range, Position } from '../main';
 
 suite('Text Document Lines Model Validator', () => {
 	function newDocument(str: string) {
@@ -62,6 +62,17 @@ suite('Text Document Lines Model Validator', () => {
 		assert.equal(newDocument(str).lineCount, 3);
 	})
 
+	test('getText(Range)', () => {
+		var str = "12345\n12345\n12345";
+		var lm = newDocument(str);
+		assert.equal(lm.getText(), str);
+		assert.equal(lm.getText(Range.create(-1, 0, 0, 5)), "12345");
+		assert.equal(lm.getText(Range.create(0, 0, 0, 5)), "12345");
+		assert.equal(lm.getText(Range.create(0, 4, 1, 1)), "5\n1");
+		assert.equal(lm.getText(Range.create(0, 4, 2, 1)), "5\n12345\n1");
+		assert.equal(lm.getText(Range.create(0, 4, 3, 1)), "5\n12345\n12345");
+		assert.equal(lm.getText(Range.create(0, 0, 3, 5)), str);
+	});
 
 	test('Invalid inputs', () => {
 		var str = "Hello World";