feat: update structure

cs2030s/labs/Lab6/Lab6.java

@@ -0,0 +1,162 @@
+import cs2030s.fp.*;
+import java.util.Scanner;
+
+class Lab6 {
+  public static void main(String[] args) {
+    // Create a scanner to read from standard input.
+    Scanner sc = new Scanner(System.in);
+
+    // Read a single integer from the test file
+    // and then run the appropriate test case
+    switch (sc.nextInt()) {
+      case 1:
+        test1();
+        break;
+      case 2:
+        test2();
+        break;
+      case 3:
+        test3();
+        break;
+      case 4:
+        test4();
+        break;
+      case 5:
+        test5();
+        break;
+    }
+  }
+  
+  public static void test1() {
+    Lazy<Integer> mod1 = Lazy.from(2030);
+    System.out.println(mod1.toString());
+    
+    Lazy<String> mod2 = Lazy.from(() -> "CS2030S");
+    System.out.println(mod2.toString());
+    
+    Lazy<String> hello = Lazy.from(() -> {
+      System.out.println("world!");
+      return "hello";
+    });
+    System.out.println(hello.get().toString());
+    System.out.println(hello.get().toString());
+  }
+  
+  public static void test2() {
+    Memo<Integer> mod1 = Memo.from(2030);
+    System.out.println(mod1.toString());
+    
+    Memo<String> mod2 = Memo.from(() -> "CS2030S");
+    System.out.println(mod2.toString());
+    System.out.println(mod2.get());
+    System.out.println(mod2.toString());
+    
+    Memo<String> hello = Memo.from(() -> {
+      System.out.println("world!");
+      return "hello";
+    });
+    System.out.println(hello.get().toString());
+    System.out.println(hello.get().toString());
+  }
+  
+  public static void test3() {
+    Constant<String> password = () -> "123456";
+    Lazy<String> lazy = Lazy.from(password);
+    System.out.println(lazy.toString());
+    System.out.println(lazy.transform(str -> str.substring(0, 1)).toString());
+    
+    Memo<String> memo = Memo.from(password);
+    System.out.println(memo.toString());
+    System.out.println(memo.transform(str -> str.substring(0, 1)).toString());
+    System.out.println(memo.transform(str -> str.substring(0, 1)).get().toString());
+    System.out.println(memo.toString());
+    
+    Immutator<Integer, String> len = str -> {
+      System.out.println("length");
+      return str.length();
+    };
+    Lazy<Integer> lazyLen = lazy.transform(len);
+    System.out.println(lazyLen.toString());
+    System.out.println(lazyLen.get());
+    System.out.println(lazyLen.get());
+    
+    Memo<Integer> step1 = Memo.from(1010);
+    Memo<Integer> step2 = step1.transform(i -> i * 2);
+    Memo<Integer> step3 = step2.next(i -> Memo.from(i + 10));
+    System.out.println(step1.toString());
+    System.out.println(step2.toString());
+    System.out.println(step3.toString());
+    System.out.println(step3.get());
+    System.out.println(step2.toString());
+    System.out.println(step1.toString());
+    
+    Memo<Integer> noErr = Memo.from(0);
+    Memo<Integer> err = noErr.transform(x -> 1/x);
+    try {
+      System.out.println(err.get());
+    } catch(ArithmeticException ae) {
+      System.out.println(ae.getMessage());
+    }
+  }
+  
+  public static void test4() {
+    Combiner<String, Integer, Integer> concat = (x, y) -> {
+      System.out.println("combine");
+      return x.toString() + y.toString();
+    };
+    
+    Memo<Integer> twenty, thirty, modInt;
+    twenty = Memo.from(() -> 20);
+    thirty = Memo.from(() -> 30);
+    modInt = twenty.combine(thirty, (x, y) -> x * 100 + y);
+    Memo<String> modStr = twenty.combine(thirty, concat);
+    
+    System.out.println(twenty.toString());
+    System.out.println(thirty.toString());
+    System.out.println(modInt.toString());
+    System.out.println(modStr.toString());
+    System.out.println(modStr.get().toString());
+    System.out.println(twenty.toString());
+    System.out.println(thirty.toString());
+    System.out.println(modInt.toString());
+    
+    Combiner<String, Integer, Double> comb = (x, y) -> x.toString() + " + " + y.toString();
+    Memo<String> s = modInt.combine(Memo.from(0.1), comb);
+    System.out.println(s.toString());
+    System.out.println(s.get());
+    System.out.println(modInt.toString());
+    
+    Memo<Integer> x1 = Memo.from(1);
+    for (int i = 0; i < 10; i ++) {
+      final Memo<Integer> y1 = x1; // final just to ensure it is unchanged
+      final int j = i;
+      x1 = Memo.from(() -> { System.out.println(j); return y1.get() + y1.get(); });
+    }
+    System.out.println(x1.get());
+  }
+  
+  public static void test5() {
+    Constant<Boolean> t = new Constant<>() {
+      public Boolean init() {
+        return true;
+      }
+    };
+    Constant<Boolean> f = new Constant<>() {
+      public Boolean init() {
+        String res = "";
+        for (int i=0; i<100000; i++) {
+          res += i;
+        }
+        return false;
+      }
+    };
+    Cond cond = new And(new Or(new Bool(t), new Bool(f)), new Not(new Not(new Bool(t))));
+    
+    System.out.println(cond.toString());
+    System.out.println(cond.neg().toString());
+    System.out.println(cond.neg().neg().toString());
+    System.out.println(cond.eval());
+    System.out.println(cond.neg().toString());
+    System.out.println(cond.neg().neg().toString());
+  }
+}