gistfile1.txt

p_term :: Parser Term
p_term = t <* spaces    
  where 
    t =     IntTerm               <$> p_num (readSigned readDec)
        <|> FloatTerm             <$> p_num (readSigned readFloat)
        <|> AtomTerm              <$> p_atom
        <|> TupleTerm             <$> p_tuple
        <|> BytelistTerm . C.pack <$> p_string
        <|> ListTerm              <$> p_list
        <|> BinaryTerm   . B.pack <$> p_binary

gistfile2.htm

Again, reading very naturally: a term is t possibly followed by some whitespace. (a <* b means roughly “run a, then b, but the value of the expression is the value of a”). t in turn can be either a p_num wrapped with an IntTerm, and so forth. (In this context, <|> can very roughly be thought of as “otherwise, try..” and <$> as “wrap the results of the argument to the right with the thing on the left”.)