function scanNumber(): string {
if (text.charCodeAt(pos) === CharacterCodes._0) {
pos++;
pos++;
while (pos < text.length && isDigit(text.charCodeAt(pos))) {
pos++;
}
if (pos < text.length && text.charCodeAt(pos) === CharacterCodes.dot) {
pos++;
if (pos < text.length && isDigit(text.charCodeAt(pos))) {