feat: update structure

cs2030s/labs/Lab5/Test5.java

@@ -0,0 +1,55 @@
+import java.io.PrintStream;
+import java.io.ByteArrayOutputStream;
+
+public class Test5 {
+  public static void main(String[] args) {
+    CS2030STest we = new CS2030STest();
+    
+    cs2030s.fp.Immutator<cs2030s.fp.Actually<Integer>,Integer> half = new cs2030s.fp.Immutator<>() {
+      public cs2030s.fp.Actually<Integer> invoke(Integer p) {
+        if (p%2 == 0) {
+          return cs2030s.fp.Actually.<Integer>ok(p/2);
+        } else {
+          return cs2030s.fp.Actually.<Integer>err(new Exception("odd number"));
+        }
+      }
+    };
+    cs2030s.fp.Immutator<cs2030s.fp.Actually<Integer>,Integer> inc = new cs2030s.fp.Immutator<>() {
+      public cs2030s.fp.Actually<Integer> invoke(Integer p) {
+        return cs2030s.fp.Actually.<Integer>ok(p+1);
+      }
+    };
+    cs2030s.fp.Immutator<cs2030s.fp.Actually<Integer>,Integer> make = new cs2030s.fp.Immutator<>() {
+      public cs2030s.fp.Actually<Integer> invoke(Integer p) {
+        return cs2030s.fp.Actually.<Integer>ok(p);
+      }
+    };
+    cs2030s.fp.Constant<Integer> zero = new cs2030s.fp.Constant<>() {
+      public Integer init() {
+        return 0;
+      }
+    };
+    
+    we.expect(
+      "make.invoke(0).next(inc).next(inc).next(half)",
+      make.invoke(0).next(inc).next(inc).next(half).toString(),
+      "<1>"
+    );
+    we.expect(
+      "make.invoke(0).next(inc).next(half).next(inc)",
+      make.invoke(0).next(inc).next(half).next(inc).toString(),
+      "[java.lang.Exception] odd number"
+    );
+    
+    we.expect(
+      "make.invoke(0).next(inc).next(inc).next(half).except(zero)",
+      make.invoke(0).next(inc).next(inc).next(half).except(zero).toString(),
+      "1"
+    );
+    we.expect(
+      "make.invoke(0).next(inc).next(half).next(inc).except(zero)",
+      make.invoke(0).next(inc).next(half).next(inc).except(zero).toString(),
+      "0"
+    );
+  }
+}