[U] Sugar: subarray functions

Author: hykilpikonna

src/main/java/org/hydev/mcpm/utils/Sugar.java

@@ -0,0 +1,57 @@
+package org.hydev.mcpm.utils;
+
+import java.util.Arrays;
+
+/**
+ * Syntax sugar that java lacks
+ *
+ * @author Azalea (https://github.com/hykilpikonna)
+ * @since 2022-10-30
+ */
+public class Sugar
+{
+    /**
+     * Subarray, behaves exactly like python's arr[start:end]
+     *
+     * @param arr Array
+     * @param start Start (inclusive, negative numbers means (len - n))
+     * @param end End (non-inclusive, negative numbers means (len - n))
+     * @return Subarray
+     * @param <T> Type of the array
+     */
+    public static <T> T[] sub(T[] arr, int start, int end)
+    {
+        if (start < 0) start = arr.length + start;
+        if (start < 0) start = 0;
+        if (end < 0) end = arr.length + end;
+        if (end < 0) end = 0;
+        if (start > end) start = end;
+        return Arrays.copyOfRange(arr, start, end);
+    }
+
+    /**
+     * Subarray from start, behaves exactly like python's arr[start:]
+     *
+     * @param arr Array
+     * @param start Start (inclusive, negative numbers means (len - n))
+     * @return Subarray
+     * @param <T> Type of the array
+     */
+    public static <T> T[] subFrom(T[] arr, int start)
+    {
+        return sub(arr, start, arr.length);
+    }
+
+    /**
+     * Subarray to end, behaves exactly like python's arr[:end]
+     *
+     * @param arr Array
+     * @param end End (non-inclusive, negative numbers means (len - n))
+     * @return Subarray
+     * @param <T> Type of the array
+     */
+    public static <T> T[] subTo(T[] arr, int end)
+    {
+        return sub(arr, 0, end);
+    }
+}