- | Helper function for parsing spaces. Parse a single space character.
s_char :: Parser String
s_char =   string " "
       <|> string "\t"
       <|> string "\r"
       <|> string "\n"
       <|> string "\f"
       <?> "space character"

s_char :: Parser String
s_char =   string " "
       <|> string "\t"
       <|> string "\r"
       <|> string "\n"
       <|> string "\f"
       <?> "space character"
s_char =   string " "
       <|> string "\t"
       <|> string "\r"
       <|> string "\n"
       <|> string "\f"
       <?> "space character"