add markdown-language-features to sqlops (#2338)

extensions/markdown-language-features/src/tableOfContentsProvider.ts

@@ -0,0 +1,100 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+
+import { MarkdownEngine } from './markdownEngine';
+
+export class Slug {
+	private static specialChars: any = { 'à': 'a', 'ä': 'a', 'ã': 'a', 'á': 'a', 'â': 'a', 'æ': 'a', 'å': 'a', 'ë': 'e', 'è': 'e', 'é': 'e', 'ê': 'e', 'î': 'i', 'ï': 'i', 'ì': 'i', 'í': 'i', 'ò': 'o', 'ó': 'o', 'ö': 'o', 'ô': 'o', 'ø': 'o', 'ù': 'o', 'ú': 'u', 'ü': 'u', 'û': 'u', 'ñ': 'n', 'ç': 'c', 'ß': 's', 'ÿ': 'y', 'œ': 'o', 'ŕ': 'r', 'ś': 's', 'ń': 'n', 'ṕ': 'p', 'ẃ': 'w', 'ǵ': 'g', 'ǹ': 'n', 'ḿ': 'm', 'ǘ': 'u', 'ẍ': 'x', 'ź': 'z', 'ḧ': 'h', '·': '-', '/': '-', '_': '-', ',': '-', ':': '-', ';': '-', 'З': '3', 'з': '3' };
+
+	public static fromHeading(heading: string): Slug {
+		const slugifiedHeading = encodeURI(heading.trim()
+			.toLowerCase()
+			.replace(/./g, c => Slug.specialChars[c] || c)
+			.replace(/[\]\[\!\'\#\$\%\&\'\(\)\*\+\,\.\/\:\;\<\=\>\?\@\\\^\_\{\|\}\~\`]/g, '')
+			.replace(/\s+/g, '-') // Replace whitespace with -
+			.replace(/[^\w\-]+/g, '') // Remove remaining non-word chars
+			.replace(/^\-+/, '') // Remove leading -
+			.replace(/\-+$/, '') // Remove trailing -
+		);
+
+		return new Slug(slugifiedHeading);
+	}
+
+	private constructor(
+		public readonly value: string
+	) { }
+
+	public equals(other: Slug): boolean {
+		return this.value === other.value;
+	}
+}
+
+export interface TocEntry {
+	readonly slug: Slug;
+	readonly text: string;
+	readonly level: number;
+	readonly line: number;
+	readonly location: vscode.Location;
+}
+
+export class TableOfContentsProvider {
+	private toc?: TocEntry[];
+
+	public constructor(
+		private engine: MarkdownEngine,
+		private document: vscode.TextDocument
+	) { }
+
+	public async getToc(): Promise<TocEntry[]> {
+		if (!this.toc) {
+			try {
+				this.toc = await this.buildToc(this.document);
+			} catch (e) {
+				this.toc = [];
+			}
+		}
+		return this.toc;
+	}
+
+	public async lookup(fragment: string): Promise<TocEntry | undefined> {
+		const toc = await this.getToc();
+		const slug = Slug.fromHeading(fragment);
+		return toc.find(entry => entry.slug.equals(slug));
+	}
+
+	private async buildToc(document: vscode.TextDocument): Promise<TocEntry[]> {
+		const toc: TocEntry[] = [];
+		const tokens = await this.engine.parse(document.uri, document.getText());
+
+		for (const heading of tokens.filter(token => token.type === 'heading_open')) {
+			const lineNumber = heading.map[0];
+			const line = document.lineAt(lineNumber);
+			toc.push({
+				slug: Slug.fromHeading(line.text),
+				text: TableOfContentsProvider.getHeaderText(line.text),
+				level: TableOfContentsProvider.getHeaderLevel(heading.markup),
+				line: lineNumber,
+				location: new vscode.Location(document.uri, line.range)
+			});
+		}
+		return toc;
+	}
+
+	private static getHeaderLevel(markup: string): number {
+		if (markup === '=') {
+			return 1;
+		} else if (markup === '-') {
+			return 2;
+		} else { // '#', '##', ...
+			return markup.length;
+		}
+	}
+
+	private static getHeaderText(header: string): string {
+		return header.replace(/^\s*#+\s*(.*?)\s*#*$/, (_, word) => word.trim());
+	}
+}