m68k asm parser w/ scala parser combinators

m68k-parser.scala

import scala.util.parsing.combinator.RegexParsers

object InputParser extends RegexParsers {
  override val skipWhitespace = false
  val WS = """[ ]+"""r
  val CONST = """#([0-9]+|[A-Z]+)"""r
  val const = CONST
  val DATA_REG = """D[0-9]+"""r
  val ADDR_REG = """A[0-9]+"""r
  val register = DATA_REG | ADDR_REG
  val indir = """\(""".r ~ register ~ """\)""".r
  val indir_incr = indir ~ """\+""".r
  val indir_decr = """-""".r ~ indir
  val DISPL = """[0-9]+"""r
  val index_displ = DISPL ~ indir
  val SIZE = """\.[WL]"""r
  var sized_register = register ~ SIZE
  val index_base_displ = DISPL ~ """\(""".r ~ register ~ """,""".r ~ WS ~ sized_register ~ """\)""".r
  val ADDRESS = """[0-9]+"""r
  val absolute = ADDRESS ~ SIZE
  val operand = const | register | indir | indir_incr | indir_decr | index_displ | index_base_displ | absolute
  val DATA_OPCODE = """[A-Z]+"""r
  val data_op_1 = DATA_OPCODE ~ opt(SIZE) ~ WS ~ operand
  val data_op_2 = DATA_OPCODE ~ opt(SIZE) ~ WS ~ operand ~ """,""".r ~ WS ~ operand
  val line = data_op_2 | data_op_1

  def parse(in: String) = parseAll(line, in) match {
    case Success(res, _) => res
    case f:Failure => throw new Exception(f.toString)
  }
}

/*val lines = io.Source.stdin.getLines*/
val lines = List(
  "ADD #3"
, "ADD.W D3"
, "MUL D3, D2"
, "MUL -(D3)"
, "MUL 2(A3, D2.W), 33.W"
)
for (l <- lines) println(InputParser.parse(l));

def tp(parser: InputParser.Parser[_], s: String) =
  println(InputParser.parseAll(parser, s))
tp(InputParser.operand, "D3")
tp(InputParser.line, "MUL D3, D2")