(#1513) Cleanup types and simplify some code

src/main/java/org/cactoos/iterable/IterableOf.java

@@ -24,7 +24,6 @@
 package org.cactoos.iterable;
 
 import java.util.Iterator;
-import java.util.List;
 import org.cactoos.Scalar;
 import org.cactoos.func.FallbackFrom;
 import org.cactoos.iterator.IteratorOf;
@@ -46,7 +45,6 @@
  * @since 0.12
  * @checkstyle ClassDataAbstractionCouplingCheck (550 lines)
  */
-@SuppressWarnings("PMD.OnlyOneConstructorShouldDoInitialization")
 public final class IterableOf<X> implements Iterable<X> {
 
     /**
@@ -63,14 +61,6 @@ public IterableOf(final X... items) {
         this(() -> new IteratorOf<>(items));
     }
 
-    /**
-     * Ctor.
-     * @param list The list
-     */
-    public IterableOf(final List<? extends X> list) {
-        this(list::iterator);
-    }
-
     /**
      * Ctor.
      * @param list The list

src/main/java/org/cactoos/iterable/Joined.java

@@ -44,24 +44,15 @@ public Joined(final Iterable<? extends T>... items) {
         this(new IterableOf<>(items));
     }
 
-    /**
-     * Ctor.
-     * @param items Items to concatenate
-     * @since 0.21
-     */
-    public Joined(final Iterator<Iterable<? extends T>> items) {
-        this(new IterableOf<>(items));
-    }
-
     /**
      * Ctor.
      * @param item First item
      * @param items Iterable
      * @since 0.32
      */
     @SuppressWarnings("unchecked")
-    public Joined(final T item, final Iterable<T> items) {
-        super(new Joined<>(new IterableOf<>(item), items));
+    public Joined(final T item, final Iterable<? extends T> items) {
+        this(new IterableOf<>(new IterableOf<>(item), items));
     }
 
     /**
@@ -72,10 +63,9 @@ public Joined(final Iterable<Iterable<? extends T>> items) {
         super(
             new IterableOf<>(
                 () -> new org.cactoos.iterator.Joined<>(
-                    new Mapped<>(Iterable::iterator, items)
+                    new Mapped<Iterator<? extends T>>(Iterable::iterator, items)
                 )
             )
         );
     }
-
 }

src/main/java/org/cactoos/iterable/Sticky.java

@@ -23,8 +23,7 @@
  */
 package org.cactoos.iterable;
 
-import java.util.Collection;
-import java.util.LinkedList;
+import org.cactoos.list.ListOf;
 import org.cactoos.scalar.Mapped;
 
 /**
@@ -50,19 +49,13 @@ public Sticky(final X... src) {
      * Ctor.
      * @param iterable The iterable
      */
-    public Sticky(final Iterable<X> iterable) {
+    public Sticky(final Iterable<? extends X> iterable) {
         super(
-            new IterableOf<>(
+            new IterableOf<X>(
                 new Mapped<>(
                     Iterable::iterator,
-                    new org.cactoos.scalar.Sticky<Iterable<X>>(
-                        () -> {
-                            final Collection<X> temp = new LinkedList<>();
-                            for (final X item : iterable) {
-                                temp.add(item);
-                            }
-                            return temp;
-                        }
+                    new org.cactoos.scalar.Sticky<>(
+                        () -> new ListOf<>(iterable)
                     )
                 )
             )

src/main/java/org/cactoos/iterator/Joined.java

@@ -25,7 +25,7 @@
 
 import java.util.Collections;
 import java.util.Iterator;
-import org.cactoos.list.ListOf;
+import org.cactoos.iterable.IterableOf;
 
 /**
  * A few Iterators joined together.
@@ -40,27 +40,38 @@ public final class Joined<T> implements Iterator<T> {
     /**
      * Iterators.
      */
-    private final Iterator<Iterator<T>> iters;
+    private final Iterator<Iterator<? extends T>> iters;
 
     /**
      * Current traversal iterator.
      */
-    private Iterator<T> current;
+    private Iterator<? extends T> current;
 
     /**
      * Ctor.
      * @param items Items to concatenate
      */
     @SafeVarargs
-    public Joined(final Iterator<T>... items) {
-        this(new ListOf<>(items));
+    public Joined(final Iterator<? extends T>... items) {
+        this(new IterableOf<>(items));
+    }
+
+    /**
+     * Ctor.
+     * @param item First item
+     * @param items Iterable
+     * @since 0.49
+     */
+    @SuppressWarnings("unchecked")
+    public Joined(final T item, final Iterator<? extends T> items) {
+        this(new IterableOf<>(new IteratorOf<>(item), items));
     }
 
     /**
      * Ctor.
      * @param items Items to concatenate
      */
-    public Joined(final Iterable<Iterator<T>> items) {
+    public Joined(final Iterable<Iterator<? extends T>> items) {
         this.iters = items.iterator();
         this.current = Collections.emptyIterator();
     }

src/main/java/org/cactoos/map/MapOf.java

@@ -144,16 +144,11 @@ public <Z> MapOf(
      * @param list List of the entries
      * @since 0.12
      */
-    @SuppressWarnings("unchecked")
     public MapOf(
         final Map<? extends X, ? extends Y> src,
         final Iterable<Map.Entry<? extends X, ? extends Y>> list
     ) {
-        this(
-            new Joined<>(
-                src.entrySet(), list
-            )
-        );
+        this(new Joined<Map.Entry<? extends X, ? extends Y>>(src.entrySet(), list));
     }
 
     /**

src/main/java/org/cactoos/scalar/MultiplicationOf.java

@@ -81,7 +81,7 @@ public MultiplicationOf(final Iterable<? extends Number> src) {
             return new Folded<>(
                 BigDecimal.ONE,
                 (mtn, value) -> mtn.multiply(value, MathContext.DECIMAL128),
-                    new Mapped<>(
+                    new Mapped<BigDecimal>(
                         number -> BigDecimal.valueOf(number.doubleValue()),
                         src
                     )

src/main/java/org/cactoos/scalar/PropertiesOf.java

@@ -100,12 +100,10 @@ public PropertiesOf(final Map.Entry<?, ?>... entries) {
     public PropertiesOf(final Iterable<Map.Entry<?, ?>> entries) {
         this(
             new MapOf<>(
-                new Mapped<>(
-                    input -> new MapEntry<>(
-                        input.getKey().toString(), input.getValue().toString()
-                    ),
-                    entries
-                )
+                input -> new MapEntry<>(
+                    input.getKey().toString(), input.getValue().toString()
+                ),
+                entries
             )
         );
     }

src/main/java/org/cactoos/scalar/SumOf.java

@@ -50,13 +50,6 @@
  *
  * @since 0.9
  */
-@SuppressWarnings(
-    {
-        "PMD.CallSuperInConstructor",
-        "PMD.OnlyOneConstructorShouldDoInitialization",
-        "PMD.ConstructorOnlyInitializesOrCallOtherConstructors"
-    }
-)
 public final class SumOf extends NumberEnvelope {
 
     /**
@@ -108,7 +101,7 @@ public SumOf(final Iterable<? extends Number> src) {
         super(() -> new Folded<>(
             BigDecimal.ZERO,
             (sum, value) -> sum.add(value, MathContext.DECIMAL128),
-            new Mapped<>(
+            new Mapped<BigDecimal>(
                 number -> BigDecimal.valueOf(number.doubleValue()),
                 src
             )).value().doubleValue()

src/main/java/org/cactoos/scalar/SumOfDouble.java

@@ -42,25 +42,14 @@
  *
  * @since 0.30
  */
-public final class SumOfDouble implements Scalar<Double> {
-
-    /**
-     * Varargs of Scalar to sum up values from.
-     */
-    private final Scalar<Double>[] scalars;
-
+public final class SumOfDouble extends ScalarEnvelope<Double> {
     /**
      * Ctor.
      * @param src Varargs of Scalar to sum up values from
      * @since 0.30
      */
     @SafeVarargs
     public SumOfDouble(final Scalar<Double>... src) {
-        this.scalars = src;
-    }
-
-    @Override
-    public Double value() {
-        return new SumOfScalar(this.scalars).value().doubleValue();
+        super(new Mapped<>(Number::doubleValue, new SumOfScalar(src)));
     }
 }

src/main/java/org/cactoos/scalar/SumOfFloat.java

@@ -42,25 +42,14 @@
  *
  * @since 0.30
  */
-public final class SumOfFloat implements Scalar<Float> {
-
-    /**
-     * Varargs of Scalar to sum up values from.
-     */
-    private final Scalar<Float>[] scalars;
-
+public final class SumOfFloat extends ScalarEnvelope<Float> {
     /**
      * Ctor.
      * @param src Varargs of Scalar to sum up values from
      * @since 0.30
      */
     @SafeVarargs
     public SumOfFloat(final Scalar<Float>... src) {
-        this.scalars = src;
-    }
-
-    @Override
-    public Float value() {
-        return new SumOfScalar(this.scalars).value().floatValue();
+        super(new Mapped<>(Number::floatValue, new SumOfScalar(src)));
     }
 }

src/main/java/org/cactoos/scalar/SumOfInt.java

@@ -43,25 +43,14 @@
  *
  * @since 0.30
  */
-public final class SumOfInt implements Scalar<Integer> {
-
-    /**
-     * Varargs of Scalar to sum up values from.
-     */
-    private final Scalar<Integer>[] scalars;
-
+public final class SumOfInt extends ScalarEnvelope<Integer> {
     /**
      * Ctor.
      * @param src Varargs of Scalar to sum up values from
      * @since 0.30
      */
     @SafeVarargs
     public SumOfInt(final Scalar<Integer>... src) {
-        this.scalars = src;
-    }
-
-    @Override
-    public Integer value() {
-        return new SumOfScalar(this.scalars).value().intValue();
+        super(new Mapped<>(Number::intValue, new SumOfScalar(src)));
     }
 }

src/main/java/org/cactoos/scalar/SumOfLong.java

@@ -42,25 +42,14 @@
  *
  * @since 0.30
  */
-public final class SumOfLong implements Scalar<Long> {
-
-    /**
-     * Varargs of Scalar to sum up values from.
-     */
-    private final Scalar<Long>[] scalars;
-
+public final class SumOfLong extends ScalarEnvelope<Long> {
     /**
      * Ctor.
      * @param src Varargs of Scalar to sum up values from
      * @since 0.30
      */
     @SafeVarargs
     public SumOfLong(final Scalar<Long>... src) {
-        this.scalars = src;
-    }
-
-    @Override
-    public Long value() {
-        return new SumOfScalar(this.scalars).value().longValue();
+        super(new Mapped<>(Number::longValue, new SumOfScalar(src)));
     }
 }

src/main/java/org/cactoos/scalar/SumOfScalar.java

@@ -23,10 +23,8 @@
  */
 package org.cactoos.scalar;
 
-import java.util.stream.Collectors;
 import org.cactoos.Scalar;
-import org.cactoos.iterable.IterableOf;
-import org.cactoos.list.ListOf;
+import org.cactoos.iterable.Mapped;
 
 /**
  * Make a scalar which is sum of scalar's values.
@@ -40,33 +38,14 @@
  *
  * @since 0.30
  */
-final class SumOfScalar implements Scalar<SumOf> {
-
-    /**
-     * Varargs of Scalar to sum up values from.
-     */
-    private final Scalar<? extends Number>[] scalars;
-
+final class SumOfScalar extends ScalarEnvelope<Number> {
     /**
      * Ctor.
      * @param src Varargs of Scalar to sum up values from
      * @since 0.30
      */
     @SafeVarargs
     SumOfScalar(final Scalar<? extends Number>... src) {
-        this.scalars = src;
-    }
-
-    @Override
-    public SumOf value() {
-        return new SumOf(
-            new IterableOf<>(
-                new ListOf<>(this.scalars)
-                    .stream()
-                    .map(
-                        scalar -> new Unchecked<>(scalar).value()
-                    ).collect(Collectors.toList())
-            )
-        );
+        super(() -> new SumOf(new Mapped<>(Scalar::value, src)));
     }
 }

src/test/java/org/cactoos/func/ChainedTest.java

@@ -51,7 +51,7 @@ void withoutIterable() throws Exception {
                     new Mapped<>(
                         new Chained<>(
                             input -> input.concat("1"),
-                            input -> input.concat("2")
+                            (String input) -> input.concat("2")
                         ),
                         new IterableOf<>("public", "final", "class")
                     )