return new BitVector(bit.makeArray(length));
}
- public BigInteger getUnsignedValue()
+ public static BitVector from(long value, int bits)
{
- if (!isBinary())
- throw new NumberFormatException("BitVector is non binary: " + toString());
- Bit[] bits = getBits();
- int length = length();
- byte[] bytes = new byte[(length / 8) + 1];
- for (int i = 0; i < length; i++)
- {
- if (Bit.ONE.equals(bits[i]))
- {
- bytes[(i / 8) + 1] |= 1 << (i % 8);
- }
- }
- return new BigInteger(bytes);
+ return from(BigInteger.valueOf(value), bits);
}
- public static BitVector from(BigInteger b, int length)
+ public static BitVector from(BigInteger value, int bits)
{
- int bitLength = b.bitLength();
- int actualLength = Integer.min(bitLength, length);
- Bit[] bits = new Bit[length];
- for (int i = 0; i < actualLength; i++)
- bits[i] = b.testBit(i) ? Bit.ONE : Bit.ZERO;
- if (b.signum() < 0)
- for (int i = actualLength; i < length; i++)
- bits[i] = Bit.ONE;
- else
- for (int i = actualLength; i < length; i++)
- bits[i] = Bit.ZERO;
- return BitVector.of(bits);
+ Bit[] values = new Bit[bits];
+ for (int i = 0; i < bits; i++)
+ values[bits - i - 1] = Bit.of(value.testBit(i));
+ return new BitVector(values);
}
public BitVectorMutator mutator()
return bits.clone();
}
+ /**
+ * Checks if all bits are {@link Bit#isBinary() binary}.
+ *
+ * @see Bit#isBinary()
+ */
public boolean isBinary()
{
for (int i = 0; i < bits.length; i++)
/**
* Returns an empty mutator which has no bits set and will simply copy the values from the first binary operation performed.
+ * <p>
+ * An empty BitVectorMutator <b>must not</b> be converted to BitVector or used to manipulate single bits until at least one two
+ * operand logic operation is performed.
*/
public static BitVectorMutator empty()
{
return new BitVectorMutator(null);
}
+ /**
+ * @see #empty()
+ */
+ public boolean isEmpty()
+ {
+ return bits == null;
+ }
+
/**
* Produces the resulting, immutable {@link BitVector}<br>
*
*/
public void setMSBit(int bitIndex, Bit bit)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot set a bit of an empty mutator");
bits[bitIndex] = bit;
}
*/
public void setLSBit(int bitIndex, Bit bit)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot set a bit of an empty mutator");
bits[bits.length - bitIndex - 1] = bit;
}
*/
public Bit getMSBit(int bitIndex)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot get a bit of an empty mutator");
return bits[bitIndex];
}
*/
public Bit getLSBit(int bitIndex)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot get a bit of an empty mutator");
return bits[bits.length - bitIndex - 1];
}
public int length()
{
+ if (bits == null)
+ throw new IllegalStateException("cannot obtain a length of an empty mutator");
return bits.length;
}
/**
* Does test for equality of values/content, shifting the other BitVector by <code>offset</code> to the right.<br>
- * Therefore <code>offset + other.length() <= this.length()</code> needs to be true.
+ * Therefore <code>offset + other.length() <= this.wdith()</code> needs to be true.
*
* @throws ArrayIndexOutOfBoundsException if <code>offset + other.length() > this.length()</code>
*
return sb.toString();
}
+ /**
+ * Returns the value of the BitVector as BigInteger.
+ *
+ * @throws NumberFormatException if the BitVector is not {@link #isBinary() binary}.
+ */
+ public BigInteger getUnsignedValue()
+ {
+ if (!isBinary())
+ throw new NumberFormatException(this + " is not binary");
+ byte[] bytes = new byte[(bits.length / 8 + (bits.length % 8 == 0 ? 0 : 1)) + 1];
+ for (int i = bits.length - 1; i >= 0; i--)
+ {
+ if (Bit.ONE == bits[bits.length - i - 1])
+ {
+ try
+ {
+ bytes[bytes.length - (i / 8) - 1] |= 1 << (i % 8);
+ }
+ catch (IndexOutOfBoundsException e)
+ {
+ e.printStackTrace();
+ }
+ }
+ }
+ return new BigInteger(bytes);
+ }
+
+ public long getUnsignedValueLong()
+ {
+ return getUnsignedValue().longValue();
+ }
+
+ /**
+ * Returns the value of the BitVector as BigInteger interpreted as a two's complement number.
+ *
+ * @throws NumberFormatException if the BitVector is not {@link #isBinary() binary}.
+ *
+ * @author Daniel Kirschten
+ */
+ public BigInteger getSignedValue()
+ {
+ BigInteger unsignedValue = getUnsignedValue();
+ if (bits[bits.length - 1] == Bit.ZERO)
+ return unsignedValue;
+ return unsignedValue.subtract(BitVector.of(Bit.ONE, bits.length).getUnsignedValue()).subtract(BigInteger.ONE);// TODO speed this up!
+ }
+
+ public long getSignedValueLong()
+ {
+ return getSignedValue().longValue();
+ }
+
/**
* Parses a String containing solely {@link Bit} symbols (MSB first)
*
return new BitVector(values);
}
- public static BitVector of(long value, int bits)
- {
- return of(BigInteger.valueOf(value), bits);
- }
-
- public static BitVector of(BigInteger value, int bits)
+ /**
+ * Changes a single Bit using the given operation. This can be used to set, clear or flip bits.
+ *
+ * @param msbIndex index of the MSB to be changed
+ * @param singleBitOperation the operation to perform on that Bit
+ * @return the resulting, new BitVektor
+ */
+ public BitVector withBitChanged(int msbIndex, UnaryOperator<Bit> singleBitOperation)
{
- Bit[] values = new Bit[bits];
- for (int i = 0; i < bits; i++)
- {
- values[bits - i - 1] = Bit.of(value.testBit(i));
- }
- return new BitVector(values);
+ Bit[] newBits = bits.clone();
+ newBits[msbIndex] = singleBitOperation.apply(newBits[msbIndex]);
+ return new BitVector(newBits);
}
/**
}
};
}
+
+ public BitVector reverse()
+ {
+ int length = length();
+ Bit[] other = new Bit[length];
+ for (int i = 0, j = length - 1; i < length; i++, j--)
+ {
+ other[i] = bits[j];
+ }
+ return new BitVector(other);
+ }
}
projects / Mograsim.git / blobdiff