equal
deleted
inserted
replaced
27 case SEQ(r1, r2) => |
27 case SEQ(r1, r2) => |
28 if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2)) |
28 if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2)) |
29 else SEQ(der(c, r1), r2) |
29 else SEQ(der(c, r1), r2) |
30 case STAR(r1) => SEQ(der(c, r1), STAR(r1)) |
30 case STAR(r1) => SEQ(der(c, r1), STAR(r1)) |
31 case NTIMES(r1, i) => |
31 case NTIMES(r1, i) => |
32 if (i == 0) ZERO else SEQ(der(c, r1), NTIMES(r1, i - 1)) |
32 if (i == 0) ZERO else der(c, SEQ(r1, NTIMES(r1, i - 1))) |
33 } |
33 } |
34 |
34 |
35 def ders (s: List[Char], r: Rexp) : Rexp = s match { |
35 def ders (s: List[Char], r: Rexp) : Rexp = s match { |
36 case Nil => r |
36 case Nil => r |
37 case c::s => ders(s, der(c, r)) |
37 case c::s => ders(s, der(c, r)) |