Add support for increment and decrement operator

Author: cpythoud

src/org/jcodegen/java/Decrement.java

@@ -0,0 +1,26 @@
+package org.jcodegen.java;
+
+public class Decrement extends IncrementDecrement<Decrement> {
+
+    public Decrement(String variable) {
+        this(variable, IncDecPosition.BEFORE);
+    }
+
+    public Decrement(String variable, IncDecPosition position) {
+        this(variable, position, 0);
+    }
+
+    public Decrement(String variable, int indentationLevel) {
+        this(variable, IncDecPosition.BEFORE, indentationLevel);
+    }
+
+    public Decrement(String variable, IncDecPosition position, int indentationLevel) {
+        super("--", variable, position, indentationLevel);
+    }
+
+
+    @Override
+    protected Decrement getThis() {
+        return this;
+    }
+}

src/org/jcodegen/java/IncDecPosition.java

@@ -0,0 +1,5 @@
+package org.jcodegen.java;
+
+public enum IncDecPosition {
+    BEFORE, AFTER
+}

src/org/jcodegen/java/Increment.java

@@ -0,0 +1,26 @@
+package org.jcodegen.java;
+
+public class Increment extends IncrementDecrement<Increment> {
+
+    public Increment(String variable) {
+        this(variable, IncDecPosition.BEFORE);
+    }
+
+    public Increment(String variable, IncDecPosition position) {
+        this(variable, position, 0);
+    }
+
+    public Increment(String variable, int indentationLevel) {
+        this(variable, IncDecPosition.BEFORE, indentationLevel);
+    }
+
+    public Increment(String variable, IncDecPosition position, int indentationLevel) {
+        super("++", variable, position, indentationLevel);
+    }
+
+
+    @Override
+    protected Increment getThis() {
+        return this;
+    }
+}

src/org/jcodegen/java/IncrementDecrement.java

@@ -0,0 +1,33 @@
+package org.jcodegen.java;
+
+abstract class IncrementDecrement<T extends IncrementDecrement<T>> extends Expression<T>  {
+
+    private final String operation;
+    private final String variable;
+    private final IncDecPosition position;
+
+    IncrementDecrement(String operation, String variable, IncDecPosition position, int indentationLevel) {
+        super(variable, indentationLevel);
+        this.operation = operation;
+        this.variable = variable;
+        this.position = position;
+    }
+
+
+    @Override
+    public String toString() {
+        final StringBuilder buf = new StringBuilder();
+
+        startExpression(buf);
+
+        if (position.equals(IncDecPosition.BEFORE))
+            buf.append(operation);
+        buf.append(variable);
+        if (position.equals(IncDecPosition.AFTER))
+            buf.append(operation);
+
+        endExpression(buf);
+
+        return buf.toString();
+    }
+}