IN (<value list>) operator broken

[jaypipes]

Somewhere along the line, the IN (value list) operator was broken:

jaypipes@uberbox:~/src/github.com/jaypipes/sqltoast/_build$ ./sqltoaster/sqltoaster "SELECT * FROM t1 WHERE a IN (1, 2)"
Syntax error.
Expected to find ')' but found literal[2]
SELECT * FROM t1 WHERE a IN (1, 2)
                               ^^^
(took 40869 nanoseconds)
jaypipes@uberbox:~/src/github.com/jaypipes/sqltoast/_build$ ./sqltoaster/sqltoaster "SELECT * FROM t1 WHERE a IN (1)"
Syntax error.
Expected to find ')' but found symbol[EOS]
SELECT * FROM t1 WHERE a IN (1)
                              ^
(took 45609 nanoseconds)

The IN (subquery) operator works just fine though:

jaypipes@uberbox:~/src/github.com/jaypipes/sqltoast/_build$ ./sqltoaster/sqltoaster "SELECT * FROM t1 WHERE a IN (SELECT b FROM t2)"
OK
statements[0]:
  <statement: SELECT
   selected columns:
     0: *
   referenced tables:
     0: t1
   where:
     column-reference[a] IN <statement: SELECT
   selected columns:
     0: column-reference[b]
   referenced tables:
     0: t2>
>

(took 31314 nanoseconds)