Add main method

mult.whl

@@ -0,0 +1,7 @@
+a := 2;
+b := 4;
+r := 0;
+while (a) {
+  r := r + b ;
+  a := a - 1
+}

src/Main.java

@@ -1,5 +1,47 @@
+import interpreter.Interpreter;
+import interpreter.InterpreterException;
+import parser.Parser;
+import parser.SyntaxException;
+import program.Program;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Map;
+
 public class Main {
     public static void main(String[] args) {
+        if (args.length == 0) {
+            System.err.println("No file given");
+        } else if (args.length > 1) {
+            System.err.println("Too many arguments");
+        } else {
+            try {
+                String code = readFile(args[0]);
+                run(code);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private static String readFile(String filename) throws IOException {
+        byte[] encoded = Files.readAllBytes(Paths.get(filename));
+        return new String(encoded, StandardCharsets.UTF_8);
+    }
 
+    private static void run(String code) {
+        try {
+            Parser parser = new Parser(code);
+            Program program = parser.parse();
+            Interpreter interpreter = new Interpreter(program);
+            Map<String, Integer> valuation = interpreter.getValuation();
+            System.out.println(valuation);
+        } catch (SyntaxException se) {
+            System.err.println(se);
+        } catch (InterpreterException ie) {
+            System.err.println(ie);
+        }
     }
 }

test/interpreter/InterpreterTest.java

@@ -10,6 +10,7 @@ import program.Composition;
 import program.Loop;
 import program.Program;
 
+import java.util.HashMap;
 import java.util.Map;
 
 import static org.junit.Assert.assertEquals;
@@ -33,4 +34,21 @@ public class InterpreterTest {
         assertEquals(0, valuation.get("a").intValue());
         assertEquals(4, valuation.get("b").intValue());
     }
+
+    @Test
+    public void testSemWithValuation() {
+        Map<String, Integer> valuation = new HashMap<>();
+        valuation.put("a", 2);
+        valuation.put("b", 4);
+        valuation.put("r", 0);
+        Program body = new Composition(
+                new Assignment(new Identifier("r"), new Addition(new Identifier("r"), new Identifier("b"))),
+                new Assignment(new Identifier("a"), new Subtraction(new Identifier("a"), new Int(1))));
+        Program loop = new Loop(new Identifier("a"), body);
+        Interpreter interpreter = new Interpreter(loop, valuation);
+        valuation = interpreter.getValuation();
+        assertEquals(8, valuation.get("r").intValue());
+        assertEquals(0, valuation.get("a").intValue());
+        assertEquals(4, valuation.get("b").intValue());
+    }
 }

test/parser/ParserTest.java

@@ -4,11 +4,8 @@ import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 import expression.*;
-import parser.Parser.Operator;
 import program.*;
 
-import java.util.Optional;
-
 public class ParserTest {
     final String loopCode = "while (a) { r := r + b ; a := a - 1 }";
     final Loop loop = new Loop(new Identifier("a"), new Composition(new Assignment(new Identifier("r"), new Addition(new Identifier("r"), new Identifier("b"))), new Assignment(new Identifier("a"), new Subtraction(new Identifier("a"), new Int(1)))));