First try for mssc, probably still has a few bugs

src/automata.cpp

@@ -1,5 +1,6 @@
 #include "Lexesis/automata.h"
 
+#include <algorithm>
 #include <climits>
 #include <queue>
 #include <string>
@@ -94,11 +95,25 @@ namespace lxs {
         return s;
     }
 
-    std::set<State> ENFA::eClose(State) {
-        
+    std::set<State> ENFA::eClose(State s) const {
+        std::set<State> states;
+        std::queue<State> statequeue;
+        statequeue.push(s);
+        while(!statequeue.empty()) {
+            auto state = statequeue.front();
+            statequeue.pop();
+            auto newStates = epsilonTransitions.find(state)->second;
+            for(auto newstate: newStates) {
+                if(states.find(newstate) == states.end()) {
+                    states.insert(newstate);
+                    statequeue.push(newstate);
+                } 
+            }
+        } 
+        return states;
     }
 
-    std::set<State> NFA::eClose(State s) {
+    std::set<State> NFA::eClose(State s) const {
         return {s};
     }
 
@@ -260,5 +275,87 @@ namespace lxs {
         computeDistinguishable(reversed, dist);
         return compress(d, reachable, dist);
     }
+    
+    namespace { // Utility functions for mssc
+        
+        std::set<State> getNextState(std::set<State> oldstate, char symbol, const NFA& e) {
+            std::set<State> states;
+            for(auto &state: oldstate) {
+                 auto a = e.delta.find(state)->second;
+                 auto newStates = a.find(symbol);
+                 if(newStates != a.end()) { 
+                     for(auto &newstate:newStates->second) {
+                        auto eclosestates = e.eClose(newstate);
+                        for(auto &eclosestate:eclosestates) {
+                            states.insert(eclosestate);
+                        }
+                     }
+                 }
+            }
+            if(states.empty()) states.insert(-1);
+            return states;
+        }
+
+    } //namespace
+    
+    DFA mssc(const NFA& e) {
+        std::map<std::set<State>,std::map<char,std::set<State> > > dfa;
+        
+        std::map<char, std::set<State> > trans;
+        for (int c = 0; c < 256; c++) {
+            trans.insert(std::pair<char,std::set<State> >(c,{(unsigned long long) -1}));
+        }
+        dfa.insert(std::pair<std::set<State>,std::map<char,std::set<State> > > ({(unsigned long long) -1},trans));
+        
+        std::queue<std::set<State> > tocheck;
+        tocheck.push(e.eClose(e.starting));
+        while(!tocheck.empty()) {
+            auto state = tocheck.front();
+            tocheck.pop();
+            std::map<char, std::set<State> > trans;
+            for (int c = 0; c < 256; c++) {
+                auto nextstate = getNextState(state,c,e);
+                trans.insert(std::pair<char,std::set<State> > (c,nextstate));
+                if(dfa.find(nextstate) == dfa.end()) {
+                    tocheck.push(nextstate);
+                }
+            } 
+            dfa.insert(std::pair<std::set<State>, std::map<char,std::set<State> > > (state,trans));
+        }
+        std::map<std::set<State>,State> lookup;
+        State numStates = 0;
+        for(auto &state:dfa) {
+            lookup.insert(std::pair<std::set<State>, State> (state.first, numStates++));
+        }
+        DFA result;
+        result.numStates = numStates;
+        result.starting = lookup.find(e.eClose(e.starting))->second;
+        std::map<Priority, State> reversepriority;
+        for(auto &state:dfa) {
+            std::set<Priority> priorityset;
+            State newstate = lookup.find(state.first)->second;
+            std::map<char,State> newtransitions;
+            for(auto &item:state.first) {
+                auto accepting = e.priority.find(item);
+                if(accepting != e.priority.end()) {
+                    priorityset.insert(accepting->second);
+                }
+            }
+            if(!priorityset.empty()) { 
+                result.accepting.insert(newstate);
+                result.priority.insert(std::pair<State,Priority> (newstate,*priorityset.begin()));
+                reversepriority.insert(std::pair<Priority,State> (*priorityset.begin(),newstate));
+            }
+            for(auto &tranition:state.second) {
+                newtransitions.insert(std::pair<char,State> (tranition.first, lookup.find(tranition.second)->second));
+            }
+            result.delta.insert(std::pair<State,std::map<char,State> > (newstate,newtransitions));
+        }
+        for(auto &priority: e.priority) {
+            auto newstate = reversepriority.find(priority.second)->second;
+            result.acceptingToken.insert(std::pair<State,std::string> (newstate,e.acceptingToken.find(priority.first)->second));
+        }
+        return result;
+    }
 
 } //namespace lxs