String convert class added

Currently with one method: splitFormatString

Converts a string to a string with separater characters based on a
format string

www/lib/CoreLibs/Convert/Strings.php

@@ -0,0 +1,81 @@
+<?php
+
+/*
+ * string convert and transform functions
+ */
+
+declare(strict_types=1);
+
+namespace CoreLibs\Convert;
+
+class Strings
+{
+	/**
+	 * split format a string base on a split format string
+	 * split format string is eg
+	 * 4-4-4 that means 4 characters DASH 4 characters DASH 4 characters
+	 * So a string in the format of
+	 * ABCD1234EFGH will be ABCD-1234-EFGH
+	 * Note a string LONGER then the maxium will be attached with the LAST
+	 * split character. In above exmaple
+	 * ABCD1234EFGHTOOLONG will be ABCD-1234-EFGH-TOOLONG
+	 *
+	 * @param  string $value            string value to split
+	 * @param  string $split_format     split format
+	 * @param  string $split_characters list of charcters with which we split
+	 *                                  if not set uses dash ('-')
+	 * @return string                   split formatted string or original value if not chnaged
+	 */
+	public static function splitFormatString(
+		string $value,
+		string $split_format,
+		string $split_charcters = '-'
+	): string {
+		// abort if split format is empty
+		if (empty($split_format)) {
+			return $value;
+		}
+		$split_list = preg_split(
+			// allowed split characters
+			"/([" . $split_charcters . "]{1})/",
+			$split_format,
+			-1,
+			PREG_SPLIT_DELIM_CAPTURE
+		);
+		// if this is false, or only one array, abort split
+		if (!is_array($split_list) || count($split_list) == 1) {
+			return $value;
+		}
+		$out = '';
+		$pos = 0;
+		$last_split = '';
+		foreach ($split_list as $offset) {
+			if (is_numeric($offset)) {
+				$_part = substr($value, $pos, (int)$offset);
+				if (empty($_part)) {
+					break;
+				}
+				$out .= $_part;
+				$pos += (int)$offset;
+			} else {
+				$out .= $offset;
+				$last_split = $offset;
+			}
+		}
+		if (!empty($out) && $pos < strlen($value)) {
+			$out .= $last_split . substr($value, $pos);
+		}
+		// if last is not alphanumeric remove, remove
+		if (!strcspn(substr($out, -1, 1), $split_charcters)) {
+			$out = substr($out, 0, -1);
+		}
+		// overwrite only if out is set
+		if (!empty($out)) {
+			return $out;
+		} else {
+			return $value;
+		}
+	}
+}
+
+// __END__