init

source/automaton.cpp

@@ -0,0 +1,78 @@
+#include "automaton.hpp"
+
+#include <stdlib.h>
+#include <string.h>
+
+using namespace std;
+
+std::string to_string(const Rule &r) {
+	return std::string() + "Rule{ translation: " + r.transition + ", irrel: " + r.irrel + " }";
+}
+
+namespace automaton {
+	const char POP    = '\01';
+	const char ACCEPT = '\02';
+
+    stack<char> symbol_stack;
+    const char * input_str;
+	size_t ip;
+
+	string irrelevant;
+
+	void (*display_callback)(decltype(input_str),
+							decltype(symbol_stack),
+							decltype(irrelevant) ir,
+                            const Rule &r) = NULL;
+
+	map<char, map<char, Rule>> matrix;
+}
+
+bool automaton::run() {
+    while (true) {
+		// Preoperation calculations
+		char n = input_str[ip];
+		if (symbol_stack.empty()) {
+            return false;
+		}
+        char m = symbol_stack.top();
+
+        Rule r("");
+        try {
+             r = matrix.at(m)
+                    .at(n);
+        } catch(...) {
+			return false;
+		}
+
+		// Render to display
+		if (display_callback) {
+			display_callback(input_str + ip, symbol_stack, irrelevant, r);
+		}
+
+		// Act on input
+		symbol_stack.pop();
+		irrelevant += r.irrel;
+
+        if (r.transition == string("") + ACCEPT) {
+            return true;
+        } if (r.transition == string("") + POP) {
+            if (not input_str[ip]) {
+                return false;
+            }
+            ip++;
+		} else {
+			for (auto it = r.transition.rbegin(); it != r.transition.rend(); it++) {
+				symbol_stack.push(*it);
+			}
+        }
+    }
+}
+
+void automaton::reset(){
+	free((char *)input_str);
+	input_str = NULL;
+    symbol_stack = stack<char>({'\0', 'E'});
+	ip = 0;
+	irrelevant = "";
+    matrix.clear();
+}