Method constructor

src/cm/modelist.ts:181–234

(
		name: string,
		caption: string | undefined,
		extensions: string | string[],
		languageExtension: LanguageExtensionProvider | null = null,
		options: AddModeOptions = {},
	)

	languageExtension: LanguageExtensionProvider | null;

	constructor(
		name: string,
		caption: string | undefined,
		extensions: string | string[],
		languageExtension: LanguageExtensionProvider | null = null,
		options: AddModeOptions = {},
	) {
		if (Array.isArray(extensions)) {
			extensions = extensions.join("|");
		}

		this.name = name;
		this.mode = name; // CodeMirror uses different mode naming
		this.extensions = extensions;
		this.caption = caption || this.name.replace(/_/g, " ");
		this.aliases = normalizeAliases(options.aliases, this.name);
		this.filenameMatchers = Array.isArray(options.filenameMatchers)
			? options.filenameMatchers.filter((matcher) => matcher instanceof RegExp)
			: [];
		this.languageExtension = languageExtension;
		let re = "";

		if (!extensions) {
			this.extRe = null;
			return;
		}

		const patterns = extensions
			.split("|")
			.map((pattern) => pattern.trim())
			.filter(Boolean);
		const filenamePatterns = patterns
			.filter((pattern) => pattern.startsWith("^"))
			.map((pattern) => `^${escapeRegExp(pattern.slice(1))}$`);
		const extensionPatterns = patterns
			.filter((pattern) => !pattern.startsWith("^"))
			.map((pattern) => escapeRegExp(pattern));
		const regexParts: string[] = [];

		if (extensionPatterns.length) {
			regexParts.push(`^.*?\\.(${extensionPatterns.join("|")})$`);
		}

		regexParts.push(...filenamePatterns);

		if (!regexParts.length) {
			this.extRe = null;
			return;
		}

		re =
			regexParts.length === 1 ? regexParts[0] : `(?:${regexParts.join("|")})`;
		this.extRe = new RegExp(re, "i");
	}

	supportsFile(filename: string): boolean {
		if (this.extRe?.test(filename)) return true;