first commit

java/expression/Const.java

@@ -0,0 +1,84 @@
+package expression;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.List;
+
+/**
+ * @author Doschennikov Nikita (me@fymio.us)
+ */
+public class Const extends AbstractExpression {
+
+    private final int intValue;
+    private final BigInteger biValue;
+    private final BigDecimal bdValue;
+    private final String repr;
+
+    public Const(int value) {
+        this.intValue = value;
+        this.biValue = BigInteger.valueOf(value);
+        this.bdValue = BigDecimal.valueOf(value);
+        this.repr = Integer.toString(value);
+    }
+
+    public Const(BigInteger value) {
+        this.intValue = value.intValueExact();
+        this.biValue = value;
+        this.bdValue = new BigDecimal(value);
+        this.repr = value.toString();
+    }
+
+    public Const(BigDecimal value) {
+        this.bdValue = value;
+        this.biValue = value.toBigIntegerExact();
+        this.intValue = biValue.intValueExact();
+        this.repr = value.toPlainString();
+    }
+
+    @Override
+    public int evaluate(int x) {
+        return intValue;
+    }
+
+    @Override
+    public int evaluate(int x, int y, int z) {
+        return intValue;
+    }
+
+    @Override
+    public int evaluate(List<Integer> vars) {
+        return intValue;
+    }
+
+    @Override
+    public BigInteger evaluateBi(List<BigInteger> vars) {
+        return biValue;
+    }
+
+    @Override
+    public BigDecimal evaluateBd(List<BigDecimal> vars) {
+        return bdValue;
+    }
+
+    @Override
+    public String toString() {
+        return repr;
+    }
+
+    @Override
+    public String toMiniString() {
+        return repr;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof Const)) return false;
+        return repr.equals(((Const) obj).repr);
+    }
+
+    @Override
+    public int hashCode() {
+        return repr.hashCode();
+    }
+}