initial commit

java/base/ExtendedRandom.java

@@ -0,0 +1,89 @@
+package base;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+/**
+ * @author Georgiy Korneev (kgeorgiy@kgeorgiy.info)
+ */
+public final class ExtendedRandom {
+    public static final String ENGLISH = "abcdefghijklmnopqrstuvwxyz";
+    public static final String RUSSIAN = "абвгдеежзийклмнопрстуфхцчшщъыьэюя";
+    public static final String GREEK = "αβγŋδεζηθικλμνξοπρτυφχψω";
+    @SuppressWarnings("StaticMethodOnlyUsedInOneClass")
+    public static final String SPACES = " \t\n\u000B\u2029\f";
+
+    private final Random random;
+
+    public ExtendedRandom(final Random random) {
+        this.random = random;
+    }
+
+    public ExtendedRandom(final Class<?> owner) {
+        this(new Random(7912736473497634913L + owner.getName().hashCode()));
+    }
+
+    public String randomString(final String chars) {
+        return randomChar(chars) + (random.nextBoolean() ? "" : randomString(chars));
+    }
+
+    public char randomChar(final String chars) {
+        return chars.charAt(nextInt(chars.length()));
+    }
+
+    public String randomString(final String chars, final int length) {
+        final StringBuilder string = new StringBuilder();
+        for (int i = 0; i < length; i++) {
+            string.append(randomChar(chars));
+        }
+        return string.toString();
+    }
+
+    public String randomString(final String chars, final int minLength, final int maxLength) {
+        return randomString(chars, nextInt(minLength, maxLength));
+    }
+
+    public boolean nextBoolean() {
+        return random.nextBoolean();
+    }
+
+    public int nextInt() {
+        return random.nextInt();
+    }
+
+    public int nextInt(final int min, final int max) {
+        return nextInt(max - min + 1) + min;
+    }
+
+    public int nextInt(final int n) {
+        return random.nextInt(n);
+    }
+
+    @SafeVarargs
+    public final <T> T randomItem(final T... items) {
+        return items[nextInt(items.length)];
+    }
+
+    public <T> T randomItem(final List<T> items) {
+        return items.get(nextInt(items.size()));
+    }
+
+    public Random getRandom() {
+        return random;
+    }
+
+    public  <T> List<T> random(final int list, final Function<ExtendedRandom, T> generator) {
+        return Stream.generate(() -> generator.apply(this)).limit(list).toList();
+    }
+
+    public double nextDouble() {
+        return random.nextDouble();
+    }
+
+    public <E> void shuffle(final List<E> all) {
+        Collections.shuffle(all, random);
+    }
+}