Calculator++ core module

calculatorpp-core/src/main/java/org/solovyev/math/units/Unit.java

@@ -0,0 +1,17 @@
+package org.solovyev.math.units;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 4/21/12
+ * Time: 7:54 PM
+ */
+public interface Unit<V> {
+
+    @NotNull
+    V getValue();
+
+    @NotNull
+    UnitType<V> getUnitType();
+}

calculatorpp-core/src/main/java/org/solovyev/math/units/UnitConverter.java

@@ -0,0 +1,42 @@
+package org.solovyev.math.units;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 4/21/12
+ * Time: 7:53 PM
+ */
+public interface UnitConverter<T> {
+
+    boolean isSupported(@NotNull UnitType<?> from, @NotNull UnitType<T> to);
+
+    @NotNull
+    Unit<T> convert(@NotNull Unit<?> from, @NotNull UnitType<T> toType);
+
+    public static class Dummy implements UnitConverter<Object> {
+
+        @NotNull
+        private static final Dummy instance = new Dummy();
+
+        @NotNull
+        public static <T> UnitConverter<T> getInstance() {
+            return (UnitConverter<T>)instance;
+        }
+
+        private Dummy() {
+        }
+
+        @Override
+        public boolean isSupported(@NotNull UnitType<?> from, @NotNull UnitType<Object> to) {
+            return false;
+        }
+
+        @NotNull
+        @Override
+        public Unit<Object> convert(@NotNull Unit<?> from, @NotNull UnitType<Object> toType) {
+            throw new IllegalArgumentException();
+        }
+    }
+
+}

calculatorpp-core/src/main/java/org/solovyev/math/units/UnitImpl.java

@@ -0,0 +1,42 @@
+package org.solovyev.math.units;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 4/21/12
+ * Time: 8:01 PM
+ */
+public class UnitImpl<V> implements Unit<V> {
+
+    @NotNull
+    private V value;
+
+    @NotNull
+    private UnitType<V> unitType;
+
+    private UnitImpl() {
+    }
+
+    @NotNull
+    public static <V> Unit<V> newInstance(@NotNull V value, @NotNull UnitType<V> unitType) {
+        final UnitImpl<V> result = new UnitImpl<V>();
+
+        result.value = value;
+        result.unitType = unitType;
+
+        return result;
+    }
+
+    @NotNull
+    @Override
+    public V getValue() {
+        return this.value;
+    }
+
+    @NotNull
+    @Override
+    public UnitType<V> getUnitType() {
+        return unitType;
+    }
+}

calculatorpp-core/src/main/java/org/solovyev/math/units/UnitType.java

@@ -0,0 +1,16 @@
+package org.solovyev.math.units;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * User: serso
+ * Date: 4/21/12
+ * Time: 7:55 PM
+ */
+public interface UnitType<V> {
+
+    @NotNull
+    Class<V> getUnitValueClass();
+
+    boolean equals(@NotNull Object o);
+}