wip

src/main/java/jef/DbSet.java

@@ -31,6 +31,11 @@ public class DbSet<T extends SerializableObject> implements Queryable<T> {
         return new SelectExpression(List.of(DatabaseSelectAllExpression.INSTANCE), new TableExpression(table), "");
     }
 
+    @Override
+    public DBSet<T> clone() {
+        return this;
+    }
+
     @Override
     public String toString() {
         return "SELECT * FROM `" + table + "`";

src/main/java/jef/Queryable.java

@@ -20,6 +20,8 @@ public interface Queryable<T extends Serializable> {
 
     Expression getExpression();
 
+    Queryable<T> clone();
+
     String toString();
 
     //stream functions
@@ -165,27 +167,27 @@ public interface Queryable<T extends Serializable> {
 //    }
 //
 //    default long count() {
-//        return 0;
+//        return new CountOp<>(this).execute();
 //    }
 //
-//    default boolean anyMatch(SerializablePredicate<? super T> SerializablePredicate) {
+//    default boolean anyMatch(SerializablePredicate<? super T> predicate) {
-//        return false;
+//        return filter(predicate).count() > 0;
 //    }
 //
-//    default boolean allMatch(SerializablePredicate<? super T> SerializablePredicate) {
+//    default boolean allMatch(SerializablePredicate<? super T> predicate) {
-//        return false;
+//        return filter(predicate).count() == clone().count();
 //    }
 //
-//    default boolean noneMatch(SerializablePredicate<? super T> SerializablePredicate) {
+//    default boolean noneMatch(SerializablePredicate<? super T> predicate) {
-//        return false;
+//        return filter(predicate).count() == 0;
 //    }
-//
+
 //    default Optional<T> findFirst() {
-//        return Optional.empty();
+//        return limit();
 //    }
 //
 //    default Optional<T> findAny() {
-//        return Optional.empty();
+//        return findFirst();
 //    }
     //</editor-fold>
 }

src/main/java/jef/QueryableProxy.java

@@ -24,6 +24,11 @@ public class QueryableProxy<T extends Serializable> implements Queryable<T> {
         return delegate.getExpression();
     }
 
+    @Override
+    public Queryable<T> clone() {
+        return new QueryableProxy<>(delegate.clone());
+    }
+
     @Override
     public Iterator<T> iterator() {
         return delegate.iterator();

src/main/java/jef/operations/CountOp.java

@@ -0,0 +1,36 @@
+package jef.operations;
+
+import jef.Queryable;
+import jef.expressions.Expression;
+import jef.expressions.SelectExpression;
+import jef.expressions.selectable.DatabaseFunctionExpression;
+
+import java.io.Serializable;
+import java.util.List;
+
+public class CountOp<T extends Serializable> implements Operation<T> {
+    private final Queryable<T> queryable;
+
+    public CountOp(Queryable<T> queryable) {
+        this.queryable = queryable;
+    }
+
+    @Override
+    public String getTableAlias() {
+        return String.valueOf((char) (queryable.getTableAlias().charAt(0) + (char) 1));
+    }
+
+    @Override
+    public Expression getExpression() {
+        return new SelectExpression(List.of(new DatabaseFunctionExpression("count(*)")), queryable.getExpression(), getTableAlias());
+    }
+
+//    @Override
+//    public CountOp<T> clone() {
+//        return new CountOp<>(queryable.clone());
+//    }
+
+    public long execute() {
+        return 0;//TODO implement when sql execution part is ready
+    }
+}

src/main/java/jef/operations/FilterOp.java

@@ -16,12 +16,11 @@ import jef.serializable.SerializablePredicate;
 
 import java.io.Serializable;
 import java.util.List;
-import java.util.function.Predicate;
 
 public class FilterOp<T extends Serializable> implements Queryable<T>, Operation<T> {
 
     private final Queryable<T> queryable;
-    private final Predicate<? super T> predicate;
+    private final SerializablePredicate<? super T> predicate;
     private final Expression predicateExpr;
 //    private final Expression finalExpr;
 
@@ -55,6 +54,11 @@ public class FilterOp<T extends Serializable> implements Queryable<T>, Operation
         return new WhereExpression(new SelectExpression(List.of(DatabaseSelectAllExpression.INSTANCE), queryable.getExpression(), getTableAlias()), predicateExpr);
     }
 
+    @Override
+    public FilterOp<T> clone() {
+        return new FilterOp<>(queryable, predicate);
+    }
+
     @Override
     public String toString() {
         return getExpression().toString();

src/main/java/jef/operations/LimitOp.java

@@ -30,6 +30,11 @@ public class LimitOp<T extends Serializable> implements Queryable<T> {
         return new LimitExpression(new SelectExpression(List.of(DatabaseSelectAllExpression.INSTANCE), queryable.getExpression(), getTableAlias()), start, count);
     }
 
+    @Override
+    public LimitOp<T> clone() {
+        return new LimitOp<>(queryable.clone(), start, count);
+    }
+
     @Override
     public String toString() {
         return getExpression().toString();