Merge branch 'highball-it-printer'

src/main/java/Main.java

@@ -3,6 +3,7 @@ import interpreter.InterpreterException;
 import parser.Parser;
 import parser.SyntaxException;
 import program.Program;
+import printer.ProgramPrinter;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
@@ -14,12 +15,20 @@ 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);
+                if (args.length == 2) {
+                  if ("--print".equals(args[1])) {
+                    print(code);
+                  } else {
+                    System.err.println("Invalid argument " + args[1]);
+                  }
+                } else if (args.length == 1) {
+                  run(code);
+                } else {
+                  System.err.println("Too many arguments");
+                }
             } catch (IOException e) {
                 e.printStackTrace();
             }
@@ -31,6 +40,17 @@ public class Main {
         return new String(encoded, StandardCharsets.UTF_8);
     }
 
+    private static void print(String code) {
+        try {
+            Parser parser = new Parser(code);
+            Program program = parser.parse();
+            ProgramPrinter printer = new ProgramPrinter();
+            System.out.println(printer.print(program));
+        } catch (SyntaxException se) {
+            System.err.println(se);
+        }
+    }
+
     private static void run(String code) {
         try {
             Parser parser = new Parser(code);

src/main/java/expression/Addition.java

@@ -28,12 +28,6 @@ public class Addition extends Expression {
         this.rightHandSide = rightHandSide;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return "(" + leftHandSide + " + " + rightHandSide + ")";
-    }
-
     /*!- Generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/main/java/expression/Identifier.java

@@ -17,12 +17,6 @@ public class Identifier extends Expression {
         this.name = name;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return name;
-    }
-
     /*!- generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/main/java/expression/Int.java

@@ -22,12 +22,6 @@ public class Int extends Expression {
         this.value = value;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return Integer.toString(value);
-    }
-
     /*!- generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/main/java/expression/Subtraction.java

@@ -28,12 +28,6 @@ public class Subtraction extends Expression {
         this.rightHandSide = rightHandSide;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return "(" + leftHandSide + " - " + rightHandSide + ")";
-    }
-
     /*!- generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/main/java/printer/ExpressionPrinter.java

@@ -0,0 +1,44 @@
+/*!! Printer */
+
+/*!
+ExpressionPrinter
+=================
+
+The `ExpressionPrinter` is used for string serialization of a given `Expression`.
+*/
+
+/*!- Header */
+package printer;
+
+import expression.*;
+import interpreter.Visitor;
+
+/*!
+The `ExpressionPrinter` implements the string serialization with the help of the
+[Visitor](${basePath}/src/main/java/interpreter/Visitor.java.html).
+*/
+public class ExpressionPrinter extends Visitor<String> {
+    public String visitAddition(Addition addition) {
+        return visit(addition.leftHandSide) + " + " + visit(addition.rightHandSide);
+    }
+
+    public String visitIdentifier(Identifier identifier) {
+        return identifier.name;
+    }
+
+    public String visitInt(Int integer) {
+        return Integer.toString(integer.value);
+    }
+
+    public String visitSubtraction(Subtraction subtraction) {
+        return visit(subtraction.leftHandSide) + " - " + visit(subtraction.rightHandSide);
+    }
+
+    /*!
+    The `print` function takes an `Expression` instance as an argument and returns
+    the string serialization of the given expression.
+    */
+    public String print(Expression expression) {
+        return visit(expression);
+    }
+}

src/main/java/printer/ProgramPrinter.java

@@ -0,0 +1,46 @@
+/*!! Printer */
+
+/*!
+ProgramPrinter
+==============
+
+The `ProgramPrinter` is used for string serialization of a given `Program`.
+*/
+
+/*!- Header */
+package printer;
+
+import interpreter.Visitor;
+import program.*;
+
+/*!
+The `ProgramPrinter` implements the string serialization with the help of the
+[Visitor](${basePath}/src/main/java/interpreter/Visitor.java.html).
+*/
+public class ProgramPrinter extends Visitor<String> {
+    private final ExpressionPrinter printer = new ExpressionPrinter();
+
+    public String visitAssignment(Assignment assignment) {
+        return printer.print(assignment.identifier) + " := " + printer.print(assignment.expression);
+    }
+
+    public String visitComposition(Composition composition) {
+        return visit(composition.first) + " ; " + visit(composition.second);
+    }
+
+    public String visitConditional(Conditional conditional) {
+        return "if (" + printer.print(conditional.condition) + ") then { " + visit(conditional.thenCase) +  " } else { " + visit(conditional.elseCase) + " }";
+    }
+
+    public String visitLoop(Loop loop) {
+        return "while (" + printer.print(loop.condition) + ") { " + visit(loop.program) +  " }";
+    }
+
+    /*!
+    The `print` function takes a `Program` instance as an argument and returns
+    the string serialization of the given program.
+    */
+    public String print(Program program) {
+        return visit(program);
+    }
+}

src/main/java/program/Assignment.java

@@ -32,12 +32,6 @@ public class Assignment extends Program {
         this.expression = expression;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return identifier + " := " + expression;
-    }
-
     /*!- generated equals method */
     @Override
     public boolean equals(Object o) {

src/main/java/program/Composition.java

@@ -19,12 +19,6 @@ public class Composition extends Program {
         this.second = second;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return first + " ; " + second;
-    }
-
     /*!- generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/main/java/program/Conditional.java

@@ -36,10 +36,4 @@ public class Conditional extends Program {
         return elseCase.equals(that.elseCase);
 
     }
-
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return "if (" + condition + ") then { " + thenCase +  " } else { " + elseCase + " }";
-    }
 }

src/main/java/program/Loop.java

@@ -21,12 +21,6 @@ public class Loop extends Program {
         this.program = program;
     }
 
-    /*!- String serialization */
-    @Override
-    public String toString() {
-        return "while (" + condition + ") { " + program +  " }";
-    }
-
     /*!- generated equals implementation */
     @Override
     public boolean equals(Object o) {

src/test/java/printer/ExpressionPrinterTest.java

@@ -0,0 +1,43 @@
+package printer;
+
+import expression.*;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class ExpressionPrinterTest {
+    final String identifierCode = "a";
+    final Identifier identifier = new Identifier(identifierCode);
+
+    final String integerCode = "42";
+    final Int integer = new Int(42);
+
+    final String additionCode = "a + 42";
+    final Addition addition = new Addition(new Identifier("a"), new Int(42));
+
+    final String subtractionCode = "1 - a";
+    final Subtraction subtraction = new Subtraction(new Int(1), new Identifier("a"));
+
+    final ExpressionPrinter printer = new ExpressionPrinter();
+
+    @Test
+    public void testVisitAddition() {
+        assertEquals(additionCode, printer.print(addition));
+    }
+
+    @Test
+    public void testVisitIdentifier() {
+        assertEquals(identifierCode, printer.print(identifier));
+    }
+
+    @Test
+    public void testVisitInt() {
+        assertEquals(integerCode, printer.print(integer));
+    }
+
+    @Test
+    public void testVisitSubtraction() {
+        assertEquals(subtractionCode, printer.print(subtraction));
+    }
+
+}

src/test/java/printer/ProgramPrinterTest.java

@@ -0,0 +1,55 @@
+package printer;
+
+import expression.Addition;
+import expression.Identifier;
+import expression.Int;
+import expression.Subtraction;
+import org.junit.Test;
+import program.*;
+
+import static org.junit.Assert.*;
+
+public class ProgramPrinterTest {
+    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)))));
+
+    final String assignmentCode = "a := 2";
+    final Assignment assignment = new Assignment(new Identifier("a"), new Int(2));
+
+    final String compositionCode = assignmentCode + " ; b := bar";
+    final Composition composition = new Composition(assignment, new Assignment(new Identifier("b"), new Identifier("bar")));
+
+    final String conditionalCode = "if (foo - bar) then { x := 5 } else { x := x }";
+    final Conditional conditional = new Conditional(new Subtraction(new Identifier("foo"), new Identifier("bar")), new Assignment(new Identifier("x"), new Int(5)), new Assignment(new Identifier("x"), new Identifier("x")));
+
+    final String programCode = compositionCode + " ; " + loopCode + " ; " + conditionalCode;
+    final Program program = new Composition(new Composition(composition, loop), conditional);
+
+    final ProgramPrinter printer = new ProgramPrinter();
+
+    @Test
+    public void testVisitAssignment() {
+        assertEquals(assignmentCode, printer.print(assignment));
+    }
+
+    @Test
+    public void testVisitComposition() {
+        assertEquals(compositionCode, printer.print(composition));
+    }
+
+    @Test
+    public void testVisitConditional() {
+        assertEquals(conditionalCode, printer.print(conditional));
+    }
+
+    @Test
+    public void testVisitLoop() {
+        assertEquals(loopCode, printer.print(loop));
+    }
+
+    @Test
+    public void testVisitProgram() {
+        assertEquals(programCode, printer.print(program));
+    }
+
+}