feat: change up organisation

2023-04-24 11:02:37 +08:00
parent 13f372ec5a
commit dd56398b7d
378 changed files with 4653 additions and 107 deletions
--- a/labs/cs2030s/MockPE2/Reader.java
+++ b/labs/cs2030s/MockPE2/Reader.java
@@ -0,0 +1,146 @@
+/**
+ * @author A0000000X
+ */
+import java.util.NoSuchElementException;
+import java.util.List;
+import java.util.ArrayList;
+
+abstract class Reader<T> {
+  protected final List<T> inputs;
+  protected Reader(List<T> inputs) {
+    this.inputs = inputs;
+  }
+  protected Reader() {
+    this.inputs = null;
+  }
+    
+  private static final Reader<?> EOF = new EOF();
+  
+  public abstract T read();
+  public abstract Reader<T> consume();
+  public abstract boolean hasNext();
+  public abstract <R> Reader<R> map(Immutator<? extends R, ? super T> f);
+  public abstract Reader<T> flatMap(Immutator<? extends Reader<? extends T>, ? super T> f);
+    
+  @SafeVarargs
+  public static <T> Reader<T> of(T... inputs) {
+    List<T> currInputs = new ArrayList<T>();
+    for (int i=0; i<inputs.length; i++) {
+      currInputs.add(inputs[i]);
+    }
+    return new NonEmpty<>(currInputs);
+  }
+  
+  public static <T> Reader<T> of() {
+    @SuppressWarnings("unchecked")
+    Reader<T> res = (Reader<T>) EOF;
+    return res;
+  }
+  
+  private static class NonEmpty<T> extends Reader<T> {
+    protected NonEmpty(List<T> inputs) {
+      super(inputs);
+    }
+    
+    @Override
+    public T read() {
+      return this.inputs.get(0);
+    }
+    
+    @Override
+    public boolean hasNext() {
+      return true;
+    }
+    
+    @Override
+    public Reader<T> consume() {
+      if (this.inputs.size() == 1) {
+        return Reader.<T>of();
+      }
+      List<T> currInputs = new ArrayList<T>(this.inputs);
+      currInputs.remove(0);
+      return new NonEmpty<>(currInputs);
+    }
+    
+    @Override
+    public <R> Reader<R> map(Immutator<? extends R, ? super T> f) {
+      List<R> currInputs = new ArrayList<R>();
+      for (int i=0; i<this.inputs.size(); i++) {
+        currInputs.add(f.invoke(this.inputs.get(i)));
+      }
+      return new NonEmpty<>(currInputs);
+    }
+    
+    @Override
+    public Reader<T> flatMap(Immutator<? extends Reader<? extends T>, ? super T> f) {
+      Reader<? extends T> tmp = f.invoke(this.inputs.get(0));
+      List<T> currInputs = new ArrayList<T>();
+      for (int i=0; i<tmp.inputs.size(); i++) {
+        currInputs.add(tmp.inputs.get(i));
+      }
+      for (int i=1; i<this.inputs.size(); i++) {
+        currInputs.add(this.inputs.get(i));
+      }
+      return new NonEmpty<>(currInputs);
+    }
+    
+    @Override
+    public String toString() {
+      return "Reader";
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) {
+        return true;
+      }
+      if (!(obj instanceof NonEmpty<?>)) {
+        return false;
+      }
+      return true;
+    }
+  }
+  
+  private static class EOF extends Reader<Object> {
+    @Override
+    public Object read() {
+      throw new NoSuchElementException();
+    }
+    
+    @Override
+    public Reader<Object> consume() {
+      throw new NoSuchElementException();
+    }
+    
+    @Override
+    public boolean hasNext() {
+      return false;
+    }
+    
+    @Override
+    public <R> Reader<R> map(Immutator<? extends R, Object> f) {
+      return Reader.of();
+    }
+    
+    @Override
+    public Reader<Object> flatMap(Immutator<? extends Reader<? extends Object>, ? super Object> f) {
+      return Reader.of();
+    }
+    
+    @Override
+    public String toString() {
+      return "EOF";
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) {
+        return true;
+      }
+      if (!(obj instanceof EOF)) {
+        return false;
+      }
+      return true;
+    }
+  }
+}