first commit

java/expression/Square.java

@@ -0,0 +1,51 @@
+package expression;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.List;
+
+/**
+ * @author Doschennikov Nikita (me@fymio.us)
+ */
+public class Square extends AbstractExpression {
+    private final AbstractExpression operand;
+
+    public Square(AbstractExpression operand) {
+        this.operand = operand;
+    }
+
+    private static int squareInt(int n) {
+        if (n == Integer.MIN_VALUE) throw new OverflowException("square");
+        int result = n * n;
+        // overflow check: result / n should == n (if n != 0)
+        if (n != 0 && result / n != n) throw new OverflowException("square");
+        return result;
+    }
+
+    @Override public int        evaluate(int x)               { return squareInt(operand.evaluate(x)); }
+    @Override public int        evaluate(int x, int y, int z) { return squareInt(operand.evaluate(x,y,z)); }
+    @Override public int        evaluate(List<Integer> vars)  { return squareInt(operand.evaluate(vars)); }
+    @Override public BigInteger evaluateBi(List<BigInteger> vars) { return operand.evaluateBi(vars).pow(2); }
+    @Override public BigDecimal evaluateBd(List<BigDecimal> vars) { return operand.evaluateBd(vars).pow(2); }
+
+    @Override public String toString()     { return "(" + operand + ")²"; }
+
+    @Override
+    public String toMiniString() {
+        String s = operand.toMiniString();
+        boolean needParens = operand instanceof AbstractBinaryOperation
+                || operand instanceof Cbrt
+                || operand instanceof Sqrt
+                || (s.startsWith("-") && (s.length() < 2 || !Character.isDigit(s.charAt(1))));
+        return needParens ? "(" + s + ")²" : s + "²";
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof Square)) return false;
+        return operand.equals(((Square) obj).operand);
+    }
+
+    @Override public int hashCode() { return operand.hashCode() ^ 0x53515232; }
+}