public Word[] GetContentsOfNthEntry(int n, GameMemory zorkFile)
{
int entrySize = GetEntrySizeInBytes(n, zorkFile);
// I have been assuming that the above call will return 4, since that
// is how many bytes are in a word entry. But it think this size
// allows there to be arbitrary entries after all the words, and they might
// be of up to this size.
// Two questions:
// 1. How do I know that we are in the size-regulated, has words-in-order
// part of the dictionary?
// 2. How do I know the size of the entries that are after the words,
// in the arbitrary-sized part of the table?
int entrySizeInWords = entrySize / 2;
Word[] retval = new Word[entrySizeInWords];
WordAddress ptrStartOfEntry = GetOffSetOfNthEntry(n, zorkFile);
for(int i = 0; i < entrySizeInWords; i++)
{
WordAddress here = new WordAddress(ptrStartOfEntry.Value + (i * 2));
retval[i] = zorkFile.ReadWord(here);
}
return retval;
}
private static string Print3ZcharsFromWord(Word word)
{
int test1 = Bits.FetchBits(BitNumber.Bit14, BitSize.Size5, word);
int test2 = Bits.FetchBits(BitNumber.Bit9, BitSize.Size5, word);
int test3 = Bits.FetchBits(BitNumber.Bit4, BitSize.Size5, word);
string str1 = Convert.ToString(test1, 2);
string str2 = Convert.ToString(test2, 2);
string str3 = Convert.ToString(test3, 2);
List<Zchar> chars = new List<Zchar>
{
new Zchar(test1),
new Zchar(test2),
new Zchar(test3)
};
return Zchar.PrintFromZchar(chars);
}
public void ZeroIsNotATerminalWord()
{
Word nonTerminal = new Word(0);
Assert.False(nonTerminal.IsTerminal());
}
public void WordAllOnesIsTerminal()
{
Word terminal = new Word(~0);
Assert.True(terminal.IsTerminal());
}
public void SettingOnlyTerminalBitMakesTerminalWord()
{
Word onlyTerminalBitSet = new Word(0x1000);
Assert.True(onlyTerminalBitSet.IsTerminal());
}
public void WriteWord(WordAddress wordAddress, Word toWrite)
{
short bytes = toWrite.Value;
byte high = (byte)((bytes >> 8) & 0xFF);
byte low = (byte)(bytes & 0xFF);
this.WriteByte(Bits.AddressOfHighByte(wordAddress), high);
this.WriteByte(Bits.AddressOfLowByte(wordAddress), low);
}
public static IEnumerable<Zchar> ReadWordAsZchars(Word word)
{
Zchar low = new Zchar(Bits.FetchBits(BitNumber.Bit14, BitSize.Size5, word));
Zchar mid = new Zchar(Bits.FetchBits(BitNumber.Bit9, BitSize.Size5, word));
Zchar high = new Zchar(Bits.FetchBits(BitNumber.Bit4, BitSize.Size5, word));
return new Zchar[] { low, mid, high };
}
public static string PrintWordAsZchars(Word word)
{
return Zchar.PrintFromZchar(ReadWordAsZchars(word));
}
private static void TestBitTwiddling()
{
int myWord = 0xBEEF;
int otherWord = 0xF000;
Word negativeOne = new Word(0xFFFF);
Word everyOther = new Word(0 + 2 + 8 + 32 + 128 + 512);
Console.WriteLine(Print3ZcharsFromWord(negativeOne));
Console.WriteLine(Print3ZcharsFromWord(everyOther));
Word word = new Word(myWord);
Word theOtherWord = new Word(otherWord);
string firstBinary = Convert.ToString(myWord, 2);
string otherWords = Convert.ToString(otherWord, 2);
var toPrint = Bits.FetchBits(BitNumber.Bit15, BitSize.Size4, word);
var otherToPrint = Bits.FetchBits(BitNumber.Bit15, BitSize.Size4, theOtherWord);
string binary = Convert.ToString(toPrint, 2);
string secondBinary = Convert.ToString(otherToPrint, 2);
Console.WriteLine($"{binary} obtained from {firstBinary}");
Console.WriteLine($"{secondBinary} obtained from {otherWords}");
}
public static int FetchBits(BitNumber high, BitSize length, Word word)
{
int mask = ~(-1 << length.Size);
int retval = (word.Value >> (high.Value - length.Size + 1)) & mask;
return retval;
}
