486
|
1 |
// eNFA that does not accept any string
|
|
2 |
def eNFA_ZERO(): NFA[TState, Char] = {
|
|
3 |
val Q = TState()
|
|
4 |
NFA(Set(Q), { case _ => Set() }, Set())
|
|
5 |
}
|
|
6 |
|
|
7 |
// eNFA that accepts the empty string
|
|
8 |
def eNFA_ONE() : NFA[TState, Char] = {
|
|
9 |
val Q = TState()
|
|
10 |
NFA(Set(Q), { case _ => Set() }, Set(Q))
|
|
11 |
}
|
|
12 |
|
|
13 |
// eNFA that accepts the string "c"
|
|
14 |
def eNFA_CHAR(c: Char) : NFA[TState, Char] = {
|
|
15 |
val Q1 = TState()
|
|
16 |
val Q2 = TState()
|
|
17 |
NFA(Set(Q1), { case (Q1, d) if (c == d) => Set(Q2) }, Set(Q2))
|
|
18 |
}
|
|
19 |
|
|
20 |
// alternative of two eNFAs
|
|
21 |
def eNFA_ALT(enfa1: NFA[TState, Char], enfa2: NFA[TState, Char]) : NFA[TState, Char] = {
|
|
22 |
val Q = TState()
|
|
23 |
val new_delta : eNFAtrans =
|
|
24 |
{ case (Q, None) => enfa1.starts | enfa2.starts }
|
|
25 |
|
|
26 |
val new_fins = (q: TState) => enfa1.fins(q) || enfa2.fins(q)
|
|
27 |
|
|
28 |
eNFA(Set(Q),
|
|
29 |
new_delta andAlso enfa1.delta andAlso enfa2.delta,
|
|
30 |
new_fins)
|
|
31 |
}
|
|
32 |
|
|
33 |
// sequence of two eNFAs
|
|
34 |
def eNFA_SEQ(enfa1: NFA[TState, Char], enfa2: NFA[TState, Char]) : NFA[TState, Char] = {
|
|
35 |
val new_delta : eNFAtrans =
|
|
36 |
{ case (q, None) if enfa1.fins(q) => enfa2.starts }
|
|
37 |
|
|
38 |
eNFA(enfa1.starts,
|
|
39 |
new_delta andAlso enfa1.delta andAlso enfa2.delta,
|
|
40 |
enfa2.fins)
|
|
41 |
}
|
|
42 |
|
|
43 |
// star of an eNFA
|
|
44 |
def eNFA_STAR(enfa: NFA[TState, Char]) : NFA[TState, Char] = {
|
|
45 |
val Q = TState()
|
|
46 |
val new_delta : eNFAtrans =
|
|
47 |
{ case (Q, None) => enfa.starts
|
|
48 |
case (q, None) if enfa.fins(q) => Set(Q) }
|
|
49 |
|
|
50 |
eNFA(Set(Q), new_delta andAlso enfa.delta, Set(Q))
|
|
51 |
}
|