Function parseExists

src/parser/syntaxes/expressions.ts:538–546

* ```abnf * Exists = "exists" Reference * ```

(s: ITokenStream)

 * ```
*/
function parseExists(s: ITokenStream): Ast.Exists {
	const startPos = s.getPos();

	s.expect(TokenKind.ExistsKeyword);
	s.next();
	const identifier = parseReference(s);

	return NODE('exists', { identifier }, startPos, s.getPos());
}

/**
 * ```abnf