Added parsers, did a bit of testing, switched to java8

4 files changed, 859 insertions, 190 deletions

diff --git a/src/jcgp/backend/function/BitwiseLogic.java b/src/jcgp/backend/function/BitwiseLogic.java
index 5d47ff7..14f4488 100644
--- a/src/jcgp/backend/function/BitwiseLogic.java
+++ b/src/jcgp/backend/function/BitwiseLogic.java
@@ -1,6 +1,5 @@
 package jcgp.backend.function;
 
-import jcgp.backend.exceptions.InvalidArgumentsException;
 import jcgp.backend.population.Connection;
 
 public class BitwiseLogic extends FunctionSet {
@@ -8,26 +7,155 @@ public class BitwiseLogic extends FunctionSet {
 	public BitwiseLogic() {
 		name = "32-bit Logic";
 		functionList = new Function[]{
+				new ConstantZero(),
+				new ConstantOne(),
+				new WireA(),
+				new WireB(),
+				new NotA(),
+				new NotB(),
 				new And(),
-				new Or(),
-				new Not(),
-				new Xor(),
-				new Nand(),
+				new AndNotA(),
+				new AndNotB(),
 				new Nor(),
-				new Xnor()};
+				new Xor(),
+				new Xnor(),
+				new Or(),
+				new OrNotA(),
+				new OrNotB(),
+				new Nand()};
+		
+		// TODO muxes
 		
 		enableAll();
 	}
+	
+	public static class ConstantZero extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			return new Long(0);
+		}
+
+		@Override
+		public int getArity() {
+			return 0;
+		}
+
+		@Override
+		public String getName() {
+			return "0";
+		}
+	}
+	
+	public static class ConstantOne extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			return new Long(Long.MAX_VALUE);
+		}
+
+		@Override
+		public int getArity() {
+			return 0;
+		}
+
+		@Override
+		public String getName() {
+			return "1";
+		}
+	}
+	
+	public static class WireA extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				return ((Long) connections[0].getValue()).longValue();
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Wire A";
+		}
+	}
+	
+	public static class WireB extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				return ((Long) connections[1].getValue()).longValue();
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Wire B";
+		}
+	}
+	
+	public static class NotA extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				return ~((Long) connections[0].getValue()).longValue();
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Not A";
+		}
+	}
+	
+	public static class NotB extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				return ~((Long) connections[1].getValue()).longValue();
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
 
+		@Override
+		public String getName() {
+			return "Not B";
+		}
+	}
+	
 	public static class And extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 & arg2;
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 & arg2;
 				
 				return result;
 			}
@@ -40,20 +168,20 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "AND";
+			return "And";
 		}
 	}
 	
-	public static class Or extends Function {
+	public static class AndNotA extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 | arg2;
-
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = ~arg1 & arg2;
+				
 				return result;
 			}
 		}
@@ -65,43 +193,69 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "OR";
+			return "And !A";
 		}
 	}
-
-	public static class Not extends Function {
+	
+	public static class AndNotB extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 1) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int result = ~arg1;
-
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 & ~arg2;
+				
 				return result;
 			}
 		}
 
 		@Override
 		public int getArity() {
-			return 1;
+			return 2;
 		}
 
 		@Override
 		public String getName() {
-			return "NOT";
+			return "And !B";
 		}
 	}
+	
+	public static class Nor extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 | arg2;
 
+				return ~result;
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Nor";
+		}
+	}
+	
 	public static class Xor extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 ^ arg2;
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 ^ arg2;
 
 				return result;
 			}
@@ -114,19 +268,19 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "XOR";
+			return "Xor";
 		}
 	}
-
-	public static class Nand extends Function {
+	
+	public static class Xnor extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 & arg2;
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 ^ arg2;
 
 				return ~result;
 			}
@@ -139,21 +293,71 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "NAND";
+			return "Xnor";
 		}
 	}
+	
+	public static class Or extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 | arg2;
 
-	public static class Nor extends Function {
+				return result;
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Or";
+		}
+	}
+	
+	public static class OrNotA extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 | arg2;
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = ~arg1 | arg2;
 
-				return ~result;
+				return result;
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Or !A";
+		}
+	}
+	
+	public static class OrNotB extends Function {
+		@Override
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 | ~arg2;
+
+				return result;
 			}
 		}
 
@@ -164,19 +368,19 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "NOR";
+			return "Or !B";
 		}
 	}
 
-	public static class Xnor extends Function {
+	public static class Nand extends Function {
 		@Override
-		public Object run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new InvalidArgumentsException("Not enough connections were given.");
+		public Long run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
 			} else {
-				int arg1 = ((int) connections[0].getValue());
-				int arg2 = ((int) connections[1].getValue());
-				int result = arg1 ^ arg2;
+				Long arg1 = ((Long) connections[0].getValue());
+				Long arg2 = ((Long) connections[1].getValue());
+				Long result = arg1 & arg2;
 
 				return ~result;
 			}
@@ -189,10 +393,7 @@ public class BitwiseLogic extends FunctionSet {
 
 		@Override
 		public String getName() {
-			return "XNOR";
+			return "Nand";
 		}
 	}
-
-	
-	
 }
diff --git a/src/jcgp/backend/function/DoubleArithmetic.java b/src/jcgp/backend/function/DoubleArithmetic.java
new file mode 100644
index 0000000..ce4826f
--- /dev/null
+++ b/src/jcgp/backend/function/DoubleArithmetic.java
@@ -0,0 +1,589 @@
+package jcgp.backend.function;
+
+import jcgp.backend.population.Connection;
+
+public class DoubleArithmetic extends FunctionSet {
+	
+	public final static double DIVISION_LIMIT = 0.0001;
+	
+	public DoubleArithmetic() {
+		name = "Double Arithmetic";
+		functionList = new Function[]{
+				new Absolute(),
+				new SquareRoot(),
+				new Reciprocal(),
+				new Sine(),
+				new Cosine(),
+				new Tangent(),
+				new Exponential(),
+				new HyperbolicSine(),
+				new HyperbolicCosine(),
+				new HyperbolicTangent(),
+				new NaturalLog(),
+				new LogBaseTen(),
+				new SineAB(),
+				new CosineAB(),
+				new Hypotenuse(),
+				new Power(),
+				new Addition(),
+				new Subtraction(),
+				new Multiplication(),
+				new Division()};
+		
+		enableAll();
+	}
+	
+	/**
+	 * Absolute returns the positive value of input 0.
+	 * 
+	 * @see Math.abs()
+	 */
+	public static class Absolute extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.abs(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Absolute";
+		}
+	}
+	
+	/**
+	 * Protected square root function, returns the square root of the absolute
+	 * value of input 0.
+	 * 
+	 * @see Math.abs(), Math.sqrt()
+	 */
+	public static class SquareRoot extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.sqrt(Math.abs(in0));
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Square root";
+		}
+	}
+	
+	/**
+	 * Protected reciprocal function, returns (1 / input 0). If input 0 is less than
+	 * {@link DoubleArithmetic.}DIVISION_LIMIT, this returns it unchanged.
+	 *
+	 */
+	public static class Reciprocal extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return in0 < DIVISION_LIMIT ? in0 : (1 / in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Reciprocal";
+		}
+	}
+	
+	/**
+	 * Sine function, in radians.
+	 *
+	 * @see Math.sin()
+	 */
+	public static class Sine extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.sin(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Sin";
+		}
+	}
+	
+	/**
+	 * Cosine function, in radians.
+	 *
+	 * @see Math.cos()
+	 */
+	public static class Cosine extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.cos(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Cos";
+		}
+	}
+	
+	/**
+	 * Protected tangent function, in radians. Returns the tangent of input 0.
+	 * If input 0 is less than {@link DoubleArithmetic.}DIVISION_LIMIT, 
+	 * this returns it unchanged.
+	 *
+	 * @see Math.tan()
+	 */
+	public static class Tangent extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return in0 < DIVISION_LIMIT ? in0 : Math.tan(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Tan";
+		}
+	}
+	
+	/**
+	 * Exponential function. Returns the exponential of input 0.
+	 *
+	 * @see Math.exp()
+	 */
+	public static class Exponential extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.exp(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Exp";
+		}
+	}
+	
+	/**
+	 * Returns the hyperbolic sine of input 0.
+	 *
+	 * @see Math.sinh()
+	 */
+	public static class HyperbolicSine extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.sinh(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Sinh";
+		}
+	}
+	
+	/**
+	 * Returns the hyperbolic cosine of input 0.
+	 *
+	 * @see Math.cosh()
+	 */
+	public static class HyperbolicCosine extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.cosh(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Cosh";
+		}
+	}
+	
+	/**
+	 * Returns the hyperbolic tangent of input 0.
+	 *
+	 * @see Math.tanh()
+	 */
+	public static class HyperbolicTangent extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return Math.tanh(in0);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Tanh";
+		}
+	}
+	
+	/**
+	 * Protected natural log function. Returns the natural log of the absolute
+	 * value of input 0. If input 0 is less than {@link DoubleArithmetic.}DIVISION_LIMIT, 
+	 * this returns it unchanged.
+	 *
+	 * @see Math.log(), Math.abs()
+	 */
+	public static class NaturalLog extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return in0 < DIVISION_LIMIT ? in0 : Math.log(Math.abs(in0));
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Ln";
+		}
+	}
+	
+	/**
+	 * Protected log base 10 function. Returns the log to base 10 the absolute
+	 * value of input 0. If input 0 is less than {@link DoubleArithmetic.}DIVISION_LIMIT, 
+	 * this returns it unchanged.
+	 *
+	 * @see Math.log10(), Math.abs()
+	 */
+	public static class LogBaseTen extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				return in0 < DIVISION_LIMIT ? in0 : Math.log10(Math.abs(in0));
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 1;
+		}
+
+		@Override
+		public String getName() {
+			return "Log";
+		}
+	}
+	
+	/**
+	 * Sine of sum. Returns the sine of the sum of inputs 0 and 1.
+	 *
+	 * @see Math.sin()
+	 */
+	public static class SineAB extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return Math.sin(in0 + in1);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Sin(a+b)";
+		}
+	}
+	
+	/**
+	 * Cosine of sum. Returns the cosine of the sum of inputs 0 and 1.
+	 *
+	 * @see Math.cos()
+	 */
+	public static class CosineAB extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return Math.cos(in0 + in1);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Cos(a+b)";
+		}
+	}
+	
+	/**
+	 * Hypotenuse function. Returns the square root of input 0 squared
+	 * plus input 1 squared.
+	 *
+	 * @see Math.hypot()
+	 */
+	public static class Hypotenuse extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return Math.hypot(in0, in1);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Hypotenuse";
+		}
+	}
+	
+	/**
+	 * Power function. Returns the absolute value of input 0 to the power of input 1.
+	 *
+	 * @see Math.abs(), Math.pow
+	 */
+	public static class Power extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return Math.pow(Math.abs(in0), in1);
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Power";
+		}
+	}
+	
+	/**
+	 * Addition returns the sum of inputs 0 and 1.
+	 *
+	 */
+	public static class Addition extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return in0 + in1;
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Addition";
+		}
+	}
+
+	/**
+	 * Subtraction returns the difference between inputs 0 and 1.
+	 *
+	 */
+	public static class Subtraction extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return in0 - in1;
+			}
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Subtraction";
+		}
+	}
+
+	/**
+	 * Multiplication returns the product of inputs 0 and 1.
+	 *
+	 */
+	public static class Multiplication extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+				return in0 * in1;
+			} 
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Multiplication";
+		}
+	}
+
+	/**
+	 * Protected division, returns the quotient of input 0 (the dividend) and input 1 (the divisor).
+	 * If the divisor is less than {@link DoubleArithmetic.}DIVISION_LIMIT, this returns the it unchanged.
+	 *
+	 */
+	public static class Division extends Function {
+		@Override
+		public Double run(Connection... connections) {
+			if (connections.length < getArity()) {
+				throw new IllegalArgumentException(getName() + " received " + connections.length + " connections but arity is " + getArity() + ".");
+			} else {
+				Double in0 = ((Double) connections[0].getValue());
+				Double in1 = ((Double) connections[1].getValue());
+
+				return in1 < DIVISION_LIMIT ? in0 : (in0 / in1);
+			} 
+		}
+
+		@Override
+		public int getArity() {
+			return 2;
+		}
+
+		@Override
+		public String getName() {
+			return "Division";
+		}
+	}
+}
diff --git a/src/jcgp/backend/function/FunctionSet.java b/src/jcgp/backend/function/FunctionSet.java
index 78801fc..1712b51 100644
--- a/src/jcgp/backend/function/FunctionSet.java
+++ b/src/jcgp/backend/function/FunctionSet.java
@@ -51,6 +51,7 @@ public abstract class FunctionSet {
 					int function = iterator.next();
 					if (function == index) {
 						iterator.remove();
+						break;
 					}
 				}
 			} else {
diff --git a/src/jcgp/backend/function/IntegerArithmetic.java b/src/jcgp/backend/function/IntegerArithmetic.java
deleted file mode 100644
index 9bb02b5..0000000
--- a/src/jcgp/backend/function/IntegerArithmetic.java
+++ /dev/null
@@ -1,122 +0,0 @@
-package jcgp.backend.function;
-
-import jcgp.backend.population.Connection;
-
-public class IntegerArithmetic extends FunctionSet {
-	
-	public IntegerArithmetic() {
-		name = "Integer Arithmetic";
-		functionList = new Function[]{
-				new Addition(),
-				new Subtraction(),
-				new Multiplication(),
-				new Division()};
-		
-		enableAll();
-	}
-	
-	public static class Addition extends Function {
-		@Override
-		public Integer run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new IllegalArgumentException("Not enough connections were given.");
-			} else {
-				Integer arg1 = ((Integer) connections[0].getValue());
-				Integer arg2 = ((Integer) connections[1].getValue());
-				Integer result = arg1 + arg2;
-
-				return result;
-			}
-		}
-
-		@Override
-		public int getArity() {
-			return 2;
-		}
-
-		@Override
-		public String getName() {
-			return "Addition";
-		}
-	}
-
-	public static class Subtraction extends Function {
-		@Override
-		public Integer run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new IllegalArgumentException("Not enough connections were given.");
-			} else {
-				Integer arg1 = ((Integer) connections[0].getValue());
-				Integer arg2 = ((Integer) connections[1].getValue());
-				Integer result = arg1 - arg2;
-
-				return result;
-			}
-		}
-
-		@Override
-		public int getArity() {
-			return 2;
-		}
-
-		@Override
-		public String getName() {
-			return "Subtraction";
-		}
-	}
-
-	public static class Multiplication extends Function {
-		@Override
-		public Integer run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new IllegalArgumentException("Not enough connections were given.");
-			} else {
-				Integer arg1 = ((Integer) connections[0].getValue());
-				Integer arg2 = ((Integer) connections[1].getValue());
-				Integer result = arg1 * arg2;
-				return result;
-			} 
-		}
-
-		@Override
-		public int getArity() {
-			return 2;
-		}
-
-		@Override
-		public String getName() {
-			return "Multiplication";
-		}
-	}
-
-	public static class Division extends Function {
-		@Override
-		public Integer run(Connection... connections) {
-			if (connections.length < 2) {
-				throw new IllegalArgumentException("Not enough connections were given.");
-			} else {
-				Integer arg1 = ((Integer) connections[0].getValue());
-				Integer arg2 = ((Integer) connections[1].getValue());
-				Integer result;
-				if (arg2 == 0) {
-					result = 0;
-				} else {
-					result = arg1 / arg2;
-				}
-
-				return result;
-			} 
-		}
-
-		@Override
-		public int getArity() {
-			return 2;
-		}
-
-		@Override
-		public String getName() {
-			return "Division";
-		}
-	}
-	
-}