lab8 current progress

2022-10-29 15:18:10 +08:00
parent 921d8a9398
commit bde57516df
16 changed files with 1672 additions and 0 deletions
--- a/Lab8/Test2.java
+++ b/Lab8/Test2.java
@@ -0,0 +1,87 @@
+import cs2030s.fp.InfiniteList;
+import cs2030s.fp.Constant;
+import cs2030s.fp.Immutator;
+import java.util.ArrayList;
+import java.util.List;
+
+class Test2 {
+  public static void main(String[] args) {
+
+    CS2030STest i = new CS2030STest();
+    i.expectReturn(
+        "InfiniteList.generate(() -> 1).map(x -> x * 2).toString()",
+        () -> InfiniteList.generate(() -> 1).map(x -> x * 2).toString(), 
+        "[? ?]");
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).toString()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).toString(), 
+        "[? ?]");
+
+    i.expectReturn(
+        "InfiniteList.generate(() -> 1).map(x -> x * 2).head()",
+        () -> InfiniteList.generate(() -> 1).map(x -> x * 2).head(), 2);
+    i.expectReturn(
+        "InfiniteList.generate(() -> 1).map(x -> x * 2).tail().head()",
+        () -> InfiniteList.generate(() -> 1).map(x -> x * 2).tail().head(), 2);
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).head()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).head(), 2);
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).tail().head()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).tail().head(), 4);
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).map(x -> x - 1).head()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).map(x -> x - 1).head(), 1);
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).map(x -> x - 1).tail().head()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x * 2).map(x -> x - 1).tail().head(), 3);
+    i.expectReturn(
+        "InfiniteList.iterate(1, x -> x + 1).map(x -> x % 2 == 0 ? null : x).tail().head()",
+        () -> InfiniteList.iterate(1, x -> x + 1).map(x -> x % 2 == 0 ? null : x).tail().head(),
+        null);
+
+    List<Integer> doublerHistory = new ArrayList<>();
+    List<Integer> generateHistory = new ArrayList<>();
+    Constant<Integer> generator = () -> { 
+      generateHistory.add(1); 
+      return 1; 
+    };
+    Immutator<Integer, Integer> doubler = x -> { 
+      doublerHistory.add(x); 
+      return x * 2; 
+    };
+
+    i.expect("InfiniteList.generate(() -> 1).map(x -> x * 2).tail().head()\n" +
+        " ..returns 2",
+        () -> InfiniteList.generate(generator).map(doubler).tail().head(), 2);
+    i.expect(" ..causes two evals of () -> 1",
+        generateHistory, List.of(1, 1));
+    i.expect(" ..causes two evals of x -> x * 2",
+        doublerHistory, List.of(1, 1));
+
+    generateHistory.retainAll(List.of());
+    doublerHistory.retainAll(List.of());
+    InfiniteList<Integer> ones = InfiniteList.generate(generator);
+    InfiniteList<Integer> twos = ones.map(doubler);
+    twos.tail().head();
+    i.expect("InfiniteList<Integer> ones = InfiniteList.generate(() -> 1)\n" + 
+        "InfiniteList<Integer> twos = ones.map(x -> x * 2)\n" + 
+        "After twos.tail().head()\n" +
+        " ..ones.toString() returns [<1> [<1> ?]]",
+        () -> ones.toString(), "[<1> [<1> ?]]");
+    i.expect(" ..twos.toString() returns [<2> [<2> ?]]",
+        () -> twos.toString(), "[<2> [<2> ?]]");
+    twos.head();
+    i.expect(" ..calling twos.head() again\n" + 
+        " ....causes zero evaluation of () -> 1",
+        generateHistory, List.of(1, 1));
+    i.expect(" ....causes zero evaluation of x -> x * 2",
+        doublerHistory, List.of(1, 1));
+    twos.tail().head();
+    i.expect(" ..calling twos.tail().head() again\n" +
+        " ....causes zero evaluation of () -> 1",
+        generateHistory, List.of(1, 1));
+    i.expect(" ....causes zero evaluation of x -> x * 2",
+        doublerHistory, List.of(1, 1));
+  }
+}