static
void getForwardReach(const raw_dfa &rdfa, map<s32, CharReach> &look) {
if (rdfa.states.size() < 2) {
return;
}
ue2::flat_set<dstate_id_t> curr, next;
curr.insert(rdfa.start_anchored);
for (u32 i = 0; i < MAX_FWD_LEN && !curr.empty(); i++) {
next.clear();
CharReach cr;
for (const auto state_id : curr) {
const dstate &ds = rdfa.states[state_id];
if (!ds.reports.empty() || !ds.reports_eod.empty()) {
return;
}
for (unsigned c = 0; c < N_CHARS; c++) {
dstate_id_t succ = ds.next[rdfa.alpha_remap[c]];
if (succ != DEAD_STATE) {
cr.set(c);
next.insert(succ);
}
}
}
assert(cr.any());
look[i] |= cr;
curr.swap(next);
}
}
static
void getForwardReach(const NGHolder &g, u32 top, map<s32, CharReach> &look) {
ue2::flat_set<NFAVertex> curr, next;
// Consider only successors of start with the required top.
for (const auto &e : out_edges_range(g.start, g)) {
NFAVertex v = target(e, g);
if (v == g.startDs) {
continue;
}
if (g[e].top == top) {
curr.insert(v);
}
}
for (u32 i = 0; i < MAX_FWD_LEN; i++) {
if (curr.empty() || contains(curr, g.accept) ||
contains(curr, g.acceptEod)) {
break;
}
next.clear();
CharReach cr;
for (auto v : curr) {
assert(!is_special(v, g));
cr |= g[v].char_reach;
insert(&next, adjacent_vertices(v, g));
}
assert(cr.any());
look[i] |= cr;
curr.swap(next);
}
}
static
void getBackwardReach(const NGHolder &g, ReportID report, u32 lag,
map<s32, CharReach> &look) {
ue2::flat_set<NFAVertex> curr, next;
for (auto v : inv_adjacent_vertices_range(g.accept, g)) {
if (contains(g[v].reports, report)) {
curr.insert(v);
}
}
for (u32 i = lag + 1; i <= MAX_BACK_LEN; i++) {
if (curr.empty() || contains(curr, g.start) ||
contains(curr, g.startDs)) {
break;
}
next.clear();
CharReach cr;
for (auto v : curr) {
assert(!is_special(v, g));
cr |= g[v].char_reach;
insert(&next, inv_adjacent_vertices(v, g));
}
assert(cr.any());
look[0 - i] |= cr;
curr.swap(next);
}
}