TP1 exercice 4.2

src/main/java/Formula.java

 public interface Formula {
+
+    public String asString();
+    public double asValue();
 }

src/main/java/Product.java

-public class Product {
+import java.util.Arrays;
+
+public class Product implements Formula {
+
+    private Formula[] formules;
+    public Product(Formula formule1, Formula formule2){
+        formules = new Formula[2];
+        formules[0] = formule1;
+        formules[1] = formule2;
+
+    }
+    public Product(Formula[] formules){
+        this.formules = Arrays.copyOf(formules, formules.length);
+    }
+
+    public double asValue(){
+        double result = 0;
+        for (Formula formule: formules) {
+            if (result == 0){
+                result = formule.asValue();
+            }else{
+                result*=formule.asValue();
+            }
+
+        }
+        return result;
+    }
+
+    public String asString() {
+        String result = "(";
+        for (int i=0;i<formules.length;i++) {
+            if (i!=0){
+                result+="*";
+            }
+            result += formules[i].asString();
+        }
+        return result+")";
+    }
 }

src/main/java/Sum.java

-public class Sum {
+import java.util.Arrays;
+
+public class Sum implements Formula{
+
+    private Formula[] formules;
+    public Sum(Formula formule1, Formula formule2){
+        formules = new Formula[2];
+        formules[0] = formule1;
+        formules[1] = formule2;
+
+    }
+    public Sum(Formula[] formules){
+        this.formules = Arrays.copyOf(formules, formules.length);
+    }
+
+    public double asValue(){
+        double result = 0;
+        for (Formula formule: formules) {
+            result += formule.asValue();
+        }
+        return result;
+    }
+
+    public String asString() {
+        String result = "(";
+        for (int i=0;i<formules.length;i++) {
+            if (i!=0){
+                result+="+";
+            }
+            result += formules[i].asString();
+        }
+        return result+")";
+    }
 }

src/main/java/Variable.java

-public class Variable {
+public class Variable implements Formula{
+
+    private String name;
+    private double value;
+
+    public Variable(String name, double value){
+        this.name = name;
+        this.value = value;
+    }
+
+    public void set(double value){
+        this.value = value;
+    }
+    public double asValue() {
+        return this.value;
+    }
+
+    public String asString(){
+        return this.name;
+    }
+
 }

src/test/java/FormulaTest.java

+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.*;
+
+public class FormulaTest {
+
+    @Test
+    void testFormula2() {
+        Variable x = new Variable("x", 2.5);
+        Variable y = new Variable("y", 4);
+        Formula formula = new Sum(x, new Product(y, new Sum(x, y)));
+        assertThat(formula.asString()).isEqualTo("(x+(y*(x+y)))");
+        assertThat(formula.asValue()).isEqualTo(28.5);
+        x.set(5);
+        assertThat(formula.asValue()).isEqualTo(41.0);
+    }
+    @Test
+    void testFormulaEnsemble() {
+        Variable x = new Variable("x", 2.5);
+        Variable y = new Variable("y", 4);
+        Variable z = new Variable("z", 1.5);
+        Formula formule1 = new Sum(x,y);
+        Formula formule2 = new Product(x,z);
+        Formula[] formules = new Formula[]{formule1, y, formule2};
+        Formula sumformules = new Sum(formules);
+        Formula proformules = new Product(formules);
+        assertThat(sumformules.asString()).isEqualTo("((x+y)+y+(x*z))");
+        assertThat(proformules.asString()).isEqualTo("((x+y)*y*(x*z))");
+        assertThat(sumformules.asValue()).isEqualTo(14.25);
+        assertThat(proformules.asValue()).isEqualTo(97.5);
+    }
+}