afl-material: progs/app6.scala@08d99acd35e8 (annotated)

262 ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	1	def simp(r: Rexp): Rexp = r match {
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	2	case ALT(r1, r2) => {
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	3	val r1s = simp(r1)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	4	val r2s = simp(r2)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	5	(r1s, r2s) match {
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	6	case (NULL, _) => r2s
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	7	case (_, NULL) => r1s
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	8	case _ => if (r1s == r2s) r1s else ALT(r1s, r2s)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	9	}
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	10	}
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	11	case SEQ(r1, r2) => {
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	12	val r1s = simp(r1)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	13	val r2s = simp(r2)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	14	(r1s, r2s) match {
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	15	case (NULL, _) => NULL
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	16	case (_, NULL) => NULL
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	17	case (EMPTY, _) => r2s
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	18	case (_, EMPTY) => r1s
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	19	case _ => SEQ(r1s, r2s)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	20	}
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	21	}
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	22	case NTIMES(r, n) => NTIMES(simp(r), n)
ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	23	case r => r
7 73cf4406b773 updated Christian Urban <urbanc@in.tum.de> parents: diff changeset	24	}
73cf4406b773 updated Christian Urban <urbanc@in.tum.de> parents: diff changeset	25
117 25999de692b2 added slides Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 93 diff changeset	26	def ders (s: List[Char], r: Rexp) : Rexp = s match {
25999de692b2 added slides Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 93 diff changeset	27	case Nil => r
262 ee4304bc6350 updated handouts Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 117 diff changeset	28	case c::s => ders(s, simp(der(c, r)))
117 25999de692b2 added slides Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 93 diff changeset	29	}
25999de692b2 added slides Christian Urban <christian dot urban at kcl dot ac dot uk> parents: 93 diff changeset	30

author	Christian Urban <christian dot urban at kcl dot ac dot uk>
	Fri, 07 Nov 2014 15:34:28 +0000 (2014-11-07)
changeset 300	08d99acd35e8
parent 262	ee4304bc6350
child 343	539b2e88f5b9
permissions	-rw-r--r--