Remove ExpressionElement#simplify

src/main/java/kroppeb/stareval/element/ExpressionElement.java

@@ -1,10 +1,4 @@
 package kroppeb.stareval.element;
 
 public interface ExpressionElement extends Element {
-	@Override
-	String toString();
-
-	default ExpressionElement simplify() {
-		return this;
-	}
 }

src/main/java/kroppeb/stareval/element/tree/BinaryExpressionElement.java

@@ -18,11 +18,4 @@ public BinaryExpressionElement(BinaryOp op, ExpressionElement left, ExpressionEl
 	public String toString() {
 		return "BinaryExpr{ {" + this.left + "} " + this.op + " {" + this.right + "} }";
 	}
-
-	@Override
-	public ExpressionElement simplify() {
-		this.left = this.left.simplify();
-		this.right = this.right.simplify();
-		return this;
-	}
 }

src/main/java/kroppeb/stareval/element/tree/FunctionCall.java

@@ -17,13 +17,4 @@ public FunctionCall(String id, List<ExpressionElement> args) {
 	public String toString() {
 		return "FunctionCall{" + this.id + " {" + this.args + "} }";
 	}
-
-	@Override
-	public ExpressionElement simplify() {
-		for (int i = 0; i < this.args.size(); i++) {
-			this.args.set(i, this.args.get(i).simplify());
-		}
-
-		return this;
-	}
 }

src/main/java/kroppeb/stareval/element/tree/UnaryExpressionElement.java

@@ -16,10 +16,4 @@ public UnaryExpressionElement(UnaryOp op, ExpressionElement inner) {
 	public String toString() {
 		return "UnaryExpr{" + this.op + " {" + this.inner + "} }";
 	}
-
-	@Override
-	public ExpressionElement simplify() {
-		this.inner = this.inner.simplify();
-		return this;
-	}
 }

src/test/java/kroppeb/stareval/parser/ParserTest.java

@@ -1,5 +1,6 @@
 package kroppeb.stareval.parser;
 
+import kroppeb.stareval.element.Element;
 import kroppeb.stareval.exception.ParseException;
 import kroppeb.stareval.element.ExpressionElement;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -37,8 +38,8 @@ void checkIfInvalidExpressionsDontParse(String input) {
 	@ParameterizedTest
 	@CsvFileSource(resources = "/fullyEquivalent.csv", delimiter = ';')
 	void checkOrderOfOperationsParse(String input1, String input2) throws ParseException {
-		ExpressionElement exp1 = parse(input1);
-		ExpressionElement exp2 = parse(input2);
-		assertEquals(exp1.simplify().toString(), exp2.simplify().toString());
+		Element exp1 = parse(input1);
+		Element exp2 = parse(input2);
+		assertEquals(exp1.toString(), exp2.toString());
 	}
 }