def parse_exponent(source, start):
 if (not (source[start] in {'e', 'E'})):
  if (source[start] in IDENTIFIER_PART):
   raise SyntaxError('Invalid number literal!')
  return start
 start += 1
 if (source[start] in {'-', '+'}):
  start += 1
 FOUND = False
 while (source[start] in NUMS):
  FOUND = True
  start += 1
 if ((not FOUND) or (source[start] in IDENTIFIER_PART)):
  raise SyntaxError('Invalid number literal!')
 return start

def parse_exponent ( source , start ) : if ( not ( source [ start ] in { 'e' , 'E' } ) ) : if ( source [ start ] in IDENTIFIER_PART ) : raise SyntaxError ( 'Invalid number literal!' ) return start start += 1 if ( source [ start ] in { '-' , '+' } ) : start += 1 FOUND = False while ( source [ start ] in NUMS ) : FOUND = True start += 1 if ( ( not FOUND ) or ( source [ start ] in IDENTIFIER_PART ) ) : raise SyntaxError ( 'Invalid number literal!' ) return start
returns end of exponential .