4 files changed, 27 insertions, 10 deletions
diff --git a/Parser.cpp b/Parser.cpp
index 08ff2b0..9b98267 100644
--- a/Parser.cpp
+++ b/Parser.cpp
@@ -83,3 +83,7 @@ void Parser::parse(string input) {
 	parse(s);
 }
 
+Parser::Parser(Circuit & circuit) {
+	set_circuit(circuit);
+}
+
diff --git a/Parser.h b/Parser.h
index b6d7bd5..271d0f4 100644
--- a/Parser.h
+++ b/Parser.h
@@ -15,6 +15,7 @@ using std::string;
 class Parser {
 public:
 	Parser() = default;
+	Parser(Circuit & circuit);
 	virtual ~Parser() = default;
 
 	void parse(string input);
diff --git a/docs/class-diag.puml b/docs/class-diag.puml
index 0417c49..b32b9bf 100644
--- a/docs/class-diag.puml
+++ b/docs/class-diag.puml
@@ -6,6 +6,7 @@ skinparam classAttributeIconSize 0
 
 class main {
 	+main(int argc, char** argv) : int
+	+open_input(int argc, char** argv) : istream*
 }
 hide main circle
 
@@ -169,6 +170,7 @@ exception ParserException {
 
 class Parser {
 	+Parser()
+	+Parser(Circuit& circuit)
 	+~Parser()
 	-circuit : Circuit*
 	-operator<<(Parser& parser, istream s) : istream&
diff --git a/main.cpp b/main.cpp
index fd528f5..d8720c1 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,5 +1,6 @@
 #include <iostream>
 #include <fstream>
+#include <istream>
 
 #include "Parser.h"
 #include "Circuit.h"
@@ -9,19 +10,30 @@
 using std::cout;
 using std::endl;
 using std::ifstream;
+using std::istream;
 
-int main(int argc, char** argv) {
-	Parser main_parser;
-	Circuit circuit;
+istream * open_input(int argc, char** argv) {
+	if (argc > 1) {
+		ifstream * file = new ifstream(argv[1]);
+		if (!file->is_open()) return nullptr;
+		return file;
+	}
+
+	return &std::cin;
+}
 
-	main_parser.set_circuit(circuit);
+int main(int argc, char** argv) {
+	istream * input = open_input(argc, argv);
+	if (input == nullptr) {
+		cout << "Could not open file" << endl;
+		return EXIT_FAILURE;
+	}
 
-	// ifstream file("circuits/and-test.txt");
-	ifstream file("circuits/full-adder.txt");
+	Circuit circuit;
+	Parser parser(circuit);
 
 	try {
-		file >> main_parser;
-		// main_parser << file;
+		*input >> parser;
 	} catch (ParserException & e) {
 		cout << "Parser error: " << e.what() << endl;
 		return EXIT_FAILURE;
@@ -35,9 +47,7 @@ int main(int argc, char** argv) {
 	  return EXIT_FAILURE;
 	}
 
-	// print results
 	cout << circuit.result();
-
 	return EXIT_SUCCESS;
 }