net.mograsim.logic.core/src/net/mograsim/logic/core/types/BitVector.java

   1 package net.mograsim.logic.core.types;
   2
   3 import static java.lang.String.format;
   4
   5 import java.util.Arrays;
   6 import java.util.Iterator;
   7 import java.util.NoSuchElementException;
   8 import java.util.Objects;
   9 import java.util.RandomAccess;
  10 import java.util.function.BinaryOperator;
  11 import java.util.function.UnaryOperator;
  12
  13 /**
  14  * Immutable class representing a {@link Bit}Vector
  15  *
  16  *
  17  * @author Christian Femers
  18  *
  19  */
  20 public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit>, RandomAccess
  21 {
  22         private final Bit[] bits;
  23
  24         private BitVector(Bit[] bits)
  25         {
  26                 for (Bit bit : bits)
  27                         if (bit == null)
  28                                 throw new NullPointerException();
  29                 this.bits = Objects.requireNonNull(bits);
  30         }
  31
  32         public static BitVector of(Bit... bits)
  33         {
  34                 return new BitVector(bits.clone());
  35         }
  36
  37         public static BitVector of(Bit bit, int length)
  38         {
  39                 return new BitVector(bit.makeArray(length));
  40         }
  41
  42         public BitVectorMutator mutator()
  43         {
  44                 return BitVectorMutator.of(this);
  45         }
  46
  47         public Bit getBit(int bitIndex)
  48         {
  49                 return bits[bitIndex];
  50         }
  51
  52         public Bit[] getBits()
  53         {
  54                 return bits.clone();
  55         }
  56
  57         @Override
  58         public BitVector join(BitVector t)
  59         {
  60                 checkCompatibility(t);
  61                 return new BitVector(binOp(bits.clone(), t.bits, Bit::join));
  62         }
  63
  64         @Override
  65         public BitVector and(BitVector t)
  66         {
  67                 checkCompatibility(t);
  68                 return new BitVector(binOp(bits.clone(), t.bits, Bit::and));
  69         }
  70
  71         @Override
  72         public BitVector or(BitVector t)
  73         {
  74                 checkCompatibility(t);
  75                 return new BitVector(binOp(bits.clone(), t.bits, Bit::or));
  76         }
  77
  78         @Override
  79         public BitVector xor(BitVector t)
  80         {
  81                 checkCompatibility(t);
  82                 return new BitVector(binOp(bits.clone(), t.bits, Bit::xor));
  83         }
  84
  85         @Override
  86         public BitVector not()
  87         {
  88                 return new BitVector(unOp(bits.clone(), Bit::not));
  89         }
  90
  91         public int length()
  92         {
  93                 return bits.length;
  94         }
  95
  96         public BitVector concat(BitVector other)
  97         {
  98                 Bit[] newBits = Arrays.copyOf(bits, length() + other.length());
  99                 System.arraycopy(other.bits, 0, newBits, length(), other.length());
 100                 return new BitVector(newBits);
 101         }
 102
 103         public BitVector subVector(int start)
 104         {
 105                 return new BitVector(Arrays.copyOfRange(bits, start, length()));
 106         }
 107
 108         public BitVector subVector(int start, int end)
 109         {
 110                 return new BitVector(Arrays.copyOfRange(bits, start, end));
 111         }
 112
 113         private void checkCompatibility(BitVector bv)
 114         {
 115                 if (length() != bv.length())
 116                         throw new IllegalArgumentException(format("BitVector length does not match: %d and %d", length(), bv.length()));
 117         }
 118
 119         static Bit[] binOp(Bit[] dest, Bit[] second, BinaryOperator<Bit> op)
 120         {
 121                 if (dest == null)
 122                         return second.clone();
 123                 for (int i = 0; i < dest.length; i++)
 124                 {
 125                         dest[i] = op.apply(dest[i], second[i]);
 126                 }
 127                 return dest;
 128         }
 129
 130         static Bit[] unOp(Bit[] dest, UnaryOperator<Bit> op)
 131         {
 132                 if (dest == null)
 133                         return null;
 134                 for (int i = 0; i < dest.length; i++)
 135                 {
 136                         dest[i] = op.apply(dest[i]);
 137                 }
 138                 return dest;
 139         }
 140
 141         /**
 142          * Class for comfortable and efficient manipulation of {@link BitVector}s, similar to {@link StringBuilder}
 143          *
 144          * @author Christian Femers
 145          */
 146         public static final class BitVectorMutator implements LogicType<BitVectorMutator, BitVector>
 147         {
 148                 private Bit[] bits;
 149
 150                 private BitVectorMutator(Bit[] bits)
 151                 {
 152                         this.bits = bits;
 153                 }
 154
 155                 static BitVectorMutator of(BitVector bv)
 156                 {
 157                         return new BitVectorMutator(bv.getBits());
 158                 }
 159
 160                 /**
 161                  * Returns a new mutator of the specified length, <b>with all bits set to <code>null</code></b>. Use with care!
 162                  */
 163                 public static BitVectorMutator ofLength(int length)
 164                 {
 165                         return new BitVectorMutator(new Bit[length]);
 166                 }
 167
 168                 /**
 169                  * Returns an empty mutator which has no bits set and will simply copy the values from the first binary operation performed.
 170                  */
 171                 public static BitVectorMutator empty()
 172                 {
 173                         return new BitVectorMutator(null);
 174                 }
 175
 176                 /**
 177                  * Produces the resulting, immutable {@link BitVector}<br>
 178                  *
 179                  * @throws IllegalStateException if the mutator is (still) empty
 180                  */
 181                 public BitVector toBitVector()
 182                 {
 183                         if (bits == null)
 184                                 throw new IllegalStateException("cannot create a BitVector from an empty mutator");
 185                         return new BitVector(bits);
 186                 }
 187
 188                 @Override
 189                 public BitVectorMutator join(BitVector t)
 190                 {
 191                         checkCompatibility(t);
 192                         bits = binOp(bits, t.bits, Bit::join);
 193                         return this;
 194                 }
 195
 196                 @Override
 197                 public BitVectorMutator and(BitVector t)
 198                 {
 199                         checkCompatibility(t);
 200                         bits = binOp(bits, t.bits, Bit::and);
 201                         return this;
 202                 }
 203
 204                 @Override
 205                 public BitVectorMutator or(BitVector t)
 206                 {
 207                         checkCompatibility(t);
 208                         bits = binOp(bits, t.bits, Bit::or);
 209                         return this;
 210                 }
 211
 212                 @Override
 213                 public BitVectorMutator xor(BitVector t)
 214                 {
 215                         checkCompatibility(t);
 216                         bits = binOp(bits, t.bits, Bit::xor);
 217                         return this;
 218                 }
 219
 220                 @Override
 221                 public BitVectorMutator not()
 222                 {
 223                         unOp(bits, Bit::not);
 224                         return this;
 225                 }
 226
 227                 public void setBit(int bitIndex, Bit bit)
 228                 {
 229                         bits[bitIndex] = bit;
 230                 }
 231
 232                 public Bit getBit(int bitIndex)
 233                 {
 234                         return bits[bitIndex];
 235                 }
 236
 237                 public int length()
 238                 {
 239                         return bits.length;
 240                 }
 241
 242                 private void checkCompatibility(BitVector bv)
 243                 {
 244                         if (bits != null && bits.length != bv.length())
 245                                 throw new IllegalArgumentException(format("BitVector length does not match: %d and %d", bits.length, bv.length()));
 246                 }
 247         }
 248
 249         /**
 250          * @see Arrays#hashCode(Object[])
 251          */
 252         @Override
 253         public int hashCode()
 254         {
 255                 return Arrays.hashCode(bits);
 256         }
 257
 258         /**
 259          * Does test for equality of values/content
 260          *
 261          * @see Object#equals(Object)
 262          */
 263         @Override
 264         public boolean equals(Object obj)
 265         {
 266                 if (this == obj)
 267                         return true;
 268                 if (!(obj instanceof BitVector))
 269                         return false;
 270                 BitVector other = (BitVector) obj;
 271                 return Arrays.equals(bits, other.bits);
 272         }
 273
 274         /**
 275          * Does test for equality of values/content, shifting the other BitVector by <code>offset</code> to the right.<br>
 276          * Therefore <code>offset + other.length() <= this.length()</code> needs to be true.
 277          *
 278          * @throws ArrayIndexOutOfBoundsException if <code>offset + other.length() > this.length()</code>
 279          *
 280          * @see Object#equals(Object)
 281          */
 282         public boolean equalsWithOffset(BitVector other, int offset)
 283         {
 284                 if (other == null)
 285                         return false;
 286                 return Arrays.equals(bits, offset, offset + other.length(), other.bits, 0, other.length());
 287         }
 288
 289         /**
 290          * All {@link Bit}s symbols concatenated together
 291          *
 292          * @see #parse(String)
 293          */
 294         @Override
 295         public String toString()
 296         {
 297                 StringBuilder sb = new StringBuilder(bits.length);
 298                 for (Bit bit : bits)
 299                         sb.append(bit);
 300                 return sb.toString();
 301         }
 302
 303         /**
 304          * Parses a String containing solely {@link Bit} symbols
 305          *
 306          * @see #toString()
 307          */
 308         public static BitVector parse(String s)
 309         {
 310                 Bit[] values = new Bit[s.length()];
 311                 for (int i = 0; i < s.length(); i++)
 312                 {
 313                         values[i] = Bit.parse(s, i);
 314                 }
 315                 return new BitVector(values);
 316         }
 317
 318         @Override
 319         public Iterator<Bit> iterator()
 320         {
 321                 return new Iterator<>()
 322                 {
 323                         private int pos = 0;
 324
 325                         @Override
 326                         public Bit next()
 327                         {
 328                                 if (!hasNext())
 329                                         throw new NoSuchElementException();
 330                                 return getBit(pos++);
 331                         }
 332
 333                         @Override
 334                         public boolean hasNext()
 335                         {
 336                                 return pos != length();
 337                         }
 338                 };
 339         }
 340 }