From 72de605659f196ebc5f856e7de43d676f2272c8e Mon Sep 17 00:00:00 2001
From: Riccardo Azzolini <riccardo4096@gmail.com>
Date: Sat, 6 Oct 2018 10:31:34 +0200
Subject: [PATCH] Define FunctionVisitor and corresponding accept method

---
 .../it/cavallium/warppi/math/Function.java    |  9 ++++
 .../warppi/math/FunctionVisitor.java          | 41 +++++++++++++++++++
 .../warppi/math/functions/Division.java       |  6 +++
 .../warppi/math/functions/EmptyNumber.java    |  6 +++
 .../warppi/math/functions/Expression.java     |  6 +++
 .../cavallium/warppi/math/functions/Joke.java |  6 +++
 .../warppi/math/functions/Logarithm.java      |  6 +++
 .../warppi/math/functions/Multiplication.java | 10 +++--
 .../warppi/math/functions/Negative.java       | 10 +++--
 .../warppi/math/functions/Number.java         |  6 +++
 .../warppi/math/functions/Power.java          |  6 +++
 .../cavallium/warppi/math/functions/Root.java |  6 +++
 .../warppi/math/functions/RootSquare.java     |  6 +++
 .../warppi/math/functions/Subtraction.java    | 10 +++--
 .../cavallium/warppi/math/functions/Sum.java  |  9 ++--
 .../warppi/math/functions/SumSubtraction.java | 10 +++--
 .../warppi/math/functions/Undefined.java      |  6 +++
 .../warppi/math/functions/Variable.java       |  6 +++
 .../math/functions/equations/Equation.java    |  6 +++
 .../functions/equations/EquationsSystem.java  |  6 +++
 .../equations/EquationsSystemPart.java        |  6 +++
 .../functions/trigonometry/ArcCosine.java     |  6 +++
 .../math/functions/trigonometry/ArcSine.java  |  6 +++
 .../functions/trigonometry/ArcTangent.java    |  6 +++
 .../math/functions/trigonometry/Cosine.java   |  6 +++
 .../math/functions/trigonometry/Sine.java     |  6 +++
 .../math/functions/trigonometry/Tangent.java  |  6 +++
 27 files changed, 199 insertions(+), 20 deletions(-)
 create mode 100644 core/src/main/java/it/cavallium/warppi/math/FunctionVisitor.java

diff --git a/core/src/main/java/it/cavallium/warppi/math/Function.java b/core/src/main/java/it/cavallium/warppi/math/Function.java
index 43bfdc32..9a72fb64 100644
--- a/core/src/main/java/it/cavallium/warppi/math/Function.java
+++ b/core/src/main/java/it/cavallium/warppi/math/Function.java
@@ -80,4 +80,13 @@ public interface Function {
 	 * @throws Error
 	 */
 	ObjectArrayList<Block> toBlock(MathContext context) throws Error;
+
+	/**
+	 * Accepts a <code>FunctionVisitor</code> by calling the correct overload of <code>visit</code>.
+	 *
+	 * @param visitor The visitor to be accepted.
+	 * @param <T> The return type of the <code>visit</code> method.
+	 * @return The value returned by <code>visit</code>.
+	 */
+	<T> T accept(FunctionVisitor<T> visitor);
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/FunctionVisitor.java b/core/src/main/java/it/cavallium/warppi/math/FunctionVisitor.java
new file mode 100644
index 00000000..34a5eebf
--- /dev/null
+++ b/core/src/main/java/it/cavallium/warppi/math/FunctionVisitor.java
@@ -0,0 +1,41 @@
+package it.cavallium.warppi.math;
+
+import it.cavallium.warppi.math.functions.*;
+import it.cavallium.warppi.math.functions.Number;
+import it.cavallium.warppi.math.functions.equations.Equation;
+import it.cavallium.warppi.math.functions.equations.EquationsSystem;
+import it.cavallium.warppi.math.functions.equations.EquationsSystemPart;
+import it.cavallium.warppi.math.functions.trigonometry.*;
+
+/**
+ * Executes a different overload of a method for each <code>Function</code> implementation.
+ *
+ * @param <T> The return type of all <code>visit</code> method overloads.
+ */
+public interface FunctionVisitor<T> {
+    T visit(ArcCosine arcCosine);
+    T visit(ArcSine arcSine);
+    T visit(ArcTangent arcTangent);
+    T visit(Cosine cosine);
+    T visit(Division division);
+    T visit(EmptyNumber emptyNumber);
+    T visit(Equation equation);
+    T visit(EquationsSystem equationsSystem);
+    T visit(EquationsSystemPart equationsSystemPart);
+    T visit(Expression expression);
+    T visit(Joke joke);
+    T visit(Logarithm logarithm);
+    T visit(Multiplication multiplication);
+    T visit(Negative negative);
+    T visit(Number number);
+    T visit(Power power);
+    T visit(Root root);
+    T visit(RootSquare rootSquare);
+    T visit(Sine sine);
+    T visit(Subtraction subtraction);
+    T visit(SumSubtraction sumSubtraction);
+    T visit(Sum sum);
+    T visit(Tangent tangent);
+    T visit(Undefined undefined);
+    T visit(Variable variable);
+}
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Division.java b/core/src/main/java/it/cavallium/warppi/math/functions/Division.java
index 5a052d81..6baeeabc 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Division.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Division.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockDivision;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -59,4 +60,9 @@ public class Division extends FunctionOperator {
 		result.add(bd);
 		return result;
 	}
+
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
 }
\ No newline at end of file
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/EmptyNumber.java b/core/src/main/java/it/cavallium/warppi/math/functions/EmptyNumber.java
index 7b0327f0..656446c8 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/EmptyNumber.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/EmptyNumber.java
@@ -2,6 +2,7 @@ package it.cavallium.warppi.math.functions;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.rules.Rule;
 import it.cavallium.warppi.util.Error;
@@ -56,4 +57,9 @@ public class EmptyNumber implements Function {
 		return null;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Expression.java b/core/src/main/java/it/cavallium/warppi/math/functions/Expression.java
index 3a9cc844..72aabb89 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Expression.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Expression.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockParenthesis;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.functions.trigonometry.ArcCosine;
 import it.cavallium.warppi.math.functions.trigonometry.ArcSine;
@@ -582,6 +583,11 @@ public class Expression extends FunctionSingle {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 	@Override
 	public String toString() {
 		String s = "(";
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Joke.java b/core/src/main/java/it/cavallium/warppi/math/functions/Joke.java
index 37b4de44..8065ee6a 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Joke.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Joke.java
@@ -2,6 +2,7 @@ package it.cavallium.warppi.math.functions;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.rules.Rule;
 import it.cavallium.warppi.util.Error;
@@ -61,4 +62,9 @@ public class Joke implements Function {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Logarithm.java b/core/src/main/java/it/cavallium/warppi/math/functions/Logarithm.java
index d4db8775..04bcd65b 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Logarithm.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Logarithm.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockLogarithm;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -55,4 +56,9 @@ public class Logarithm extends FunctionOperator {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Multiplication.java b/core/src/main/java/it/cavallium/warppi/math/functions/Multiplication.java
index b1d24858..6e632af4 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Multiplication.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Multiplication.java
@@ -3,10 +3,7 @@ package it.cavallium.warppi.math.functions;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
 import it.cavallium.warppi.gui.expression.blocks.BlockParenthesis;
-import it.cavallium.warppi.math.Function;
-import it.cavallium.warppi.math.FunctionOperator;
-import it.cavallium.warppi.math.MathContext;
-import it.cavallium.warppi.math.MathematicalSymbols;
+import it.cavallium.warppi.math.*;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
@@ -87,6 +84,11 @@ public class Multiplication extends FunctionOperator {
 		}
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 	public boolean isNegative() {
 		return parameter1.equals(new Number(getMathContext(), -1)) || parameter2.equals(new Number(getMathContext(), -1));
 	}
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Negative.java b/core/src/main/java/it/cavallium/warppi/math/functions/Negative.java
index f963b976..a6733547 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Negative.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Negative.java
@@ -3,10 +3,7 @@ package it.cavallium.warppi.math.functions;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
 import it.cavallium.warppi.gui.expression.blocks.BlockParenthesis;
-import it.cavallium.warppi.math.Function;
-import it.cavallium.warppi.math.FunctionSingle;
-import it.cavallium.warppi.math.MathContext;
-import it.cavallium.warppi.math.MathematicalSymbols;
+import it.cavallium.warppi.math.*;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
@@ -52,4 +49,9 @@ public class Negative extends FunctionSingle {
 		return blocks;
 		// throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
+
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Number.java b/core/src/main/java/it/cavallium/warppi/math/functions/Number.java
index dbeb3d9b..a6398d2a 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Number.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Number.java
@@ -4,6 +4,7 @@ import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.util.LinkedList;
 
+import it.cavallium.warppi.math.FunctionVisitor;
 import org.nevec.rjm.BigDecimalMath;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
@@ -273,6 +274,11 @@ public class Number implements Function {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 	@Override
 	public Function setParameter(final int index, final Function var) throws IndexOutOfBoundsException {
 		throw new IndexOutOfBoundsException();
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Power.java b/core/src/main/java/it/cavallium/warppi/math/functions/Power.java
index 58aec371..15940748 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Power.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Power.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockPower;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -50,4 +51,9 @@ public class Power extends FunctionOperator {
 		result.add(bp);
 		return result;
 	}
+
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Root.java b/core/src/main/java/it/cavallium/warppi/math/functions/Root.java
index 25b118a4..0ab1d6f6 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Root.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Root.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
@@ -39,4 +40,9 @@ public class Root extends FunctionOperator {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/RootSquare.java b/core/src/main/java/it/cavallium/warppi/math/functions/RootSquare.java
index 30a7351a..2a1afa2f 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/RootSquare.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/RootSquare.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockSquareRoot;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -48,4 +49,9 @@ public class RootSquare extends FunctionOperator {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Subtraction.java b/core/src/main/java/it/cavallium/warppi/math/functions/Subtraction.java
index daa0a77f..452fbfc4 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Subtraction.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Subtraction.java
@@ -2,10 +2,7 @@ package it.cavallium.warppi.math.functions;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
-import it.cavallium.warppi.math.Function;
-import it.cavallium.warppi.math.FunctionOperator;
-import it.cavallium.warppi.math.MathContext;
-import it.cavallium.warppi.math.MathematicalSymbols;
+import it.cavallium.warppi.math.*;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
@@ -43,4 +40,9 @@ public class Subtraction extends FunctionOperator {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
\ No newline at end of file
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Sum.java b/core/src/main/java/it/cavallium/warppi/math/functions/Sum.java
index 3bcff91c..36ff3814 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Sum.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Sum.java
@@ -2,10 +2,7 @@ package it.cavallium.warppi.math.functions;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
-import it.cavallium.warppi.math.Function;
-import it.cavallium.warppi.math.FunctionOperator;
-import it.cavallium.warppi.math.MathContext;
-import it.cavallium.warppi.math.MathematicalSymbols;
+import it.cavallium.warppi.math.*;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
@@ -47,4 +44,8 @@ public class Sum extends FunctionOperator {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/SumSubtraction.java b/core/src/main/java/it/cavallium/warppi/math/functions/SumSubtraction.java
index ef5a7e47..35d04df9 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/SumSubtraction.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/SumSubtraction.java
@@ -2,10 +2,7 @@ package it.cavallium.warppi.math.functions;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
-import it.cavallium.warppi.math.Function;
-import it.cavallium.warppi.math.FunctionOperator;
-import it.cavallium.warppi.math.MathContext;
-import it.cavallium.warppi.math.MathematicalSymbols;
+import it.cavallium.warppi.math.*;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
 
@@ -43,4 +40,9 @@ public class SumSubtraction extends FunctionOperator {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Undefined.java b/core/src/main/java/it/cavallium/warppi/math/functions/Undefined.java
index 38ecd971..93d74f38 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Undefined.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Undefined.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockUndefined;
 import it.cavallium.warppi.math.Function;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.rules.Rule;
 import it.cavallium.warppi.util.Error;
@@ -58,6 +59,11 @@ public class Undefined implements Function {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 	@Override
 	public String toString() {
 		return "UNDEFINED";
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/Variable.java b/core/src/main/java/it/cavallium/warppi/math/functions/Variable.java
index 119f8631..885992f7 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/Variable.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/Variable.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.gui.expression.blocks.BlockChar;
 import it.cavallium.warppi.math.Function;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.rules.Rule;
 import it.cavallium.warppi.util.Error;
@@ -130,4 +131,9 @@ public class Variable implements Function {
 		result.add(new BlockChar(getChar()));
 		return result;
 	}
+
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/equations/Equation.java b/core/src/main/java/it/cavallium/warppi/math/functions/equations/Equation.java
index 8fbd50bf..7232a69c 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/equations/Equation.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/equations/Equation.java
@@ -7,6 +7,7 @@ import java.util.Set;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionOperator;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.math.solver.SolveMethod;
 import it.cavallium.warppi.util.Error;
@@ -68,4 +69,9 @@ public class Equation extends FunctionOperator {
 		return null;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
\ No newline at end of file
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystem.java b/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystem.java
index 16d238b3..a79c2bda 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystem.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystem.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.equations;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionDynamic;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -46,4 +47,9 @@ public class EquationsSystem extends FunctionDynamic {
 		return null;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystemPart.java b/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystemPart.java
index 0d18fc46..e6670fb3 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystemPart.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/equations/EquationsSystemPart.java
@@ -2,6 +2,7 @@ package it.cavallium.warppi.math.functions.equations;
 
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -34,4 +35,9 @@ public class EquationsSystemPart extends FunctionSingle {
 		return null;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcCosine.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcCosine.java
index 46b244a8..ed722ba8 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcCosine.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcCosine.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.trigonometry;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
@@ -38,4 +39,9 @@ public class ArcCosine extends FunctionSingle {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcSine.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcSine.java
index 87e0cb2d..8989c5a3 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcSine.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcSine.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.trigonometry;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
@@ -38,4 +39,9 @@ public class ArcSine extends FunctionSingle {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcTangent.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcTangent.java
index b37af1ea..0064b546 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcTangent.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/ArcTangent.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.trigonometry;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
@@ -38,4 +39,9 @@ public class ArcTangent extends FunctionSingle {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Cosine.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Cosine.java
index 4ed7ddd3..d00c65c6 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Cosine.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Cosine.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.trigonometry;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.cavallium.warppi.util.Errors;
@@ -38,4 +39,9 @@ public class Cosine extends FunctionSingle {
 		throw new Error(Errors.NOT_IMPLEMENTED, "Unknown function " + getClass().getSimpleName());
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Sine.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Sine.java
index 2fcda089..b1c99ffa 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Sine.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Sine.java
@@ -5,6 +5,7 @@ import it.cavallium.warppi.gui.expression.blocks.BlockContainer;
 import it.cavallium.warppi.gui.expression.blocks.BlockSine;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -51,4 +52,9 @@ public class Sine extends FunctionSingle {
 		return result;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }
diff --git a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Tangent.java b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Tangent.java
index d9cca7cc..c224fb89 100644
--- a/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Tangent.java
+++ b/core/src/main/java/it/cavallium/warppi/math/functions/trigonometry/Tangent.java
@@ -3,6 +3,7 @@ package it.cavallium.warppi.math.functions.trigonometry;
 import it.cavallium.warppi.gui.expression.blocks.Block;
 import it.cavallium.warppi.math.Function;
 import it.cavallium.warppi.math.FunctionSingle;
+import it.cavallium.warppi.math.FunctionVisitor;
 import it.cavallium.warppi.math.MathContext;
 import it.cavallium.warppi.util.Error;
 import it.unimi.dsi.fastutil.objects.ObjectArrayList;
@@ -37,4 +38,9 @@ public class Tangent extends FunctionSingle {
 		return null;
 	}
 
+	@Override
+	public <T> T accept(FunctionVisitor<T> visitor) {
+		return visitor.visit(this);
+	}
+
 }