feat: update structure

cs2030s/labs/Lab5/Test4.java

@@ -0,0 +1,45 @@
+import java.io.PrintStream;
+import java.io.ByteArrayOutputStream;
+
+public class Test4 {
+  public static void main(String[] args) {
+    CS2030STest we = new CS2030STest();
+    
+    cs2030s.fp.Transformer<Integer,Integer> inc = new cs2030s.fp.Transformer<>() {
+      public Integer invoke(Integer p) {
+        return p+1;
+      }
+    };
+    cs2030s.fp.Transformer<Integer,Integer> sqr = new cs2030s.fp.Transformer<>() {
+      public Integer invoke(Integer p) {
+        return p*p;
+      }
+    };
+    
+    cs2030s.fp.Transformer<Integer,Integer> sqrPlusOneA = sqr.before(inc);
+    cs2030s.fp.Transformer<Integer,Integer> sqrPlusOneB = inc.after(sqr);
+    cs2030s.fp.Transformer<Integer,Integer> plusOneSqrA = sqr.after(inc);
+    cs2030s.fp.Transformer<Integer,Integer> plusOneSqrB = inc.before(sqr);
+    
+    we.expect(
+      "sqrPlusOneA.invoke(2)",
+      sqrPlusOneA.invoke(2).toString(),
+      "5"
+    );
+    we.expect(
+      "sqrPlusOneB.invoke(2)",
+      sqrPlusOneA.invoke(2).toString(),
+      "5"
+    );
+    we.expect(
+      "plusOneSqrA.invoke(2)",
+      plusOneSqrA.invoke(2).toString(),
+      "9"
+    );
+    we.expect(
+      "plusOneSqrB.invoke(2)",
+      plusOneSqrB.invoke(2).toString(),
+      "9"
+    );
+  }
+}