415
|
1 |
def ders2(s: List[Char], r: Rexp) : Rexp = (s, r) match {
|
|
2 |
case (Nil, r) => r
|
|
3 |
case (s, ZERO) => ZERO
|
|
4 |
case (s, ONE) => if (s == Nil) ONE else ZERO
|
|
5 |
case (s, CHAR(c)) => if (s == List(c)) ONE else
|
|
6 |
if (s == Nil) CHAR(c) else ZERO
|
|
7 |
case (s, ALT(r1, r2)) => ALT(ders2(s, r2), ders2(s, r2))
|
436
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
8 |
case (c::s, r) => ders2(s, simp(der(c, r)))
|
261
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
9 |
}
|