X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;f=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2FBit.java;h=3f25d77e6545e799913ce97b0188cd41db0316a3;hb=fb0f58aee59134ab9178baea80716dc0d62ffd83;hp=b18c5974f9d576442eb2e13256654fbf23dc8f1b;hpb=7f0a08228f5c517aa1aa22453c1b0dd533e4cd04;p=Mograsim.git

diff --git a/era.mi/src/era/mi/logic/Bit.java b/era.mi/src/era/mi/logic/Bit.java
index b18c5974..3f25d77e 100644
--- a/era.mi/src/era/mi/logic/Bit.java
+++ b/era.mi/src/era/mi/logic/Bit.java
@@ -1,62 +1,109 @@
-package era.mi.logic;
-
-
-public enum Bit
-{
-	ONE, ZERO, Z, X;
-	
-	public static Bit and(Bit a, Bit b)
-	{
-		return a.and(b);
-	}
-	
-	public Bit and(Bit other)
-	{
-		if(equals(Bit.ZERO) || other.equals(Bit.ZERO))
-			return Bit.ZERO;
-		else if(equals(other) && equals(Bit.ONE))
-			return Bit.ONE;
-		else
-			return Bit.X;
-	}
-	
-	public static Bit or(Bit a, Bit b)
-	{
-		return a.or(b);
-	}
-	
-	public Bit or(Bit other)
-	{
-		if(equals(Bit.ONE) || other.equals(Bit.ONE))
-			return Bit.ONE;
-		else if(equals(other) && equals(Bit.ZERO))
-			return Bit.ZERO;
-		else
-			return Bit.X;
-	}
-	
-	public static Bit xor(Bit a, Bit b)
-	{
-		return a.xor(b);
-	}
-	
-	public Bit xor(Bit other)
-	{
-		//I'm uncertain how this should behave for cases where one value is neither 1 nor 0.
-		//TODO: Implement xor
-		return Bit.X;
-	}
-	
-	public Bit not()
-	{
-		switch(this)
-		{
-		case ONE:
-			return Bit.ZERO;
-		case ZERO:
-			return Bit.ONE;
-		default:
-			return Bit.X;
-		}
-	}
-}
+package era.mi.logic;
+
+import java.util.Arrays;
+
+public enum Bit
+{
+	ONE, ZERO, Z, X;
+
+	public static Bit and(Bit a, Bit b)
+	{
+		return a.and(b);
+	}
+
+	public Bit and(Bit other)
+	{
+		if (this == ZERO || other == ZERO)
+			return ZERO;
+		else if (this == other && this == ONE)
+			return ONE;
+		else if (this == X || other == X)
+			return X;
+		else
+			return ZERO;
+	}
+
+	public static Bit or(Bit a, Bit b)
+	{
+		return a.or(b);
+	}
+
+	public Bit or(Bit other)
+	{
+		if (this == ONE || other == ONE)
+			return ONE;
+		else if (this == other && this == ZERO)
+			return ZERO;
+		else if (this == X || other == X)
+			return X;
+		else
+			return ZERO;
+	}
+
+	public static Bit xor(Bit a, Bit b)
+	{
+		return a.xor(b);
+	}
+
+	public Bit xor(Bit other)
+	{
+		if(this == X || this == Z || other == X || other == Z)
+			return Bit.X;
+		else
+			return this == other ? ZERO : ONE;
+	}
+
+	public Bit not()
+	{
+		switch (this)
+			{
+			case ONE:
+				return Bit.ZERO;
+			case ZERO:
+				return Bit.ONE;
+			default:
+				return Bit.X;
+			}
+	}
+	
+	public Bit[] makeArray(int length)
+	{
+		Bit[] bits = new Bit[length];
+		Arrays.fill(bits, this);
+		return bits;
+	}
+
+	/**
+	 * Rules for two bits that get directly connected<br>
+	 * <code><table>
+	 * <tbody>
+	 * <tr><td><td>X<td>0<td>1<td>Z</tr>
+	 * <tr><td>X<td>X<td>X<td>X<td>X</tr>
+	 * <tr><td>0<td>X<td>0<td>X<td>0</tr>
+	 * <tr><td>1<td>X<td>X<td>1<td>1</tr>
+	 * <tr><td>Z<td>X<td>0<td>1<td>Z</tr>
+	 * </tbody>
+	 * </table><code>
+	 * 
+	 * @return the result according to the table
+	 * 
+	 * @author Christian Femers
+	 */
+	public Bit combineWith(Bit other)
+	{
+		if (this == other)
+			return this;
+		if (this == X || other == X)
+			return X;
+		if (other == Z)
+			return this;
+		if (this == Z)
+			return other;
+		return X;
+	}
+
+	public static Bit combine(Bit a, Bit b)
+	{
+		return a.combineWith(b);
+	}
+}