miken32 · May 10, 2017 23:54
diff --git a/BlockCheck.class.php b/BlockCheck.class.php
 <?php
 /**
 * BlockCheck 1.0
 *
 * Copyright (C) 2017 Michael Newton
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @package BlockCheck
 * @author Michael Newton <miken32>
 * @copyright 2017 Michael Newton
 * @license https://opensource.org/licenses/GPL-3.0 GPLv3
 * @version 1.0
 * @see http://stackoverflow.com/a/43010755/1255289
 */

 namespace Miken32;

 /**
 * BlockCheck
 *
 * A utility class to check whether or not strings are part of
 * a Unicode character block.
 *
 * Can be used statically or not. Sample usage:
 * ```
 * <?php
 * use Miken32\BlockCheck as BC;
 * if (BC::isValid("🜈🝮🝤", BC::ALCHEMICAL_SYMBOLS)) {
 *     echo "Valid characters\n";
 * } else {
 *     echo "Invalid characters\n";
 * }
 *
 * $myChecker = new BC("BASIC_LATIN");
 * $test = "Meet me at the café.";
 * if ($myChecker->check($test)) {
 *     echo "Valid characters\n";
 * } else {
 *     echo "Invalid characters\n";
 * }
 * $myChecker->addBlock(BC::LATIN_1_SUPPLEMENT);
 * if ($myChecker->check($test)) {
 *     echo "Valid characters\n";
 * } else {
 *     echo "Invalid characters\n";
 * }
 * ```
 */
 class BlockCheck
 {
    const ADLAM = [0x1E900, 0x1E95F];
    const AEGEAN_NUMBERS = [0x10100, 0x1013F];
    const AHOM = [0x11700, 0x1173F];
    const ALCHEMICAL_SYMBOLS = [0x1F700, 0x1F77F];
    const ALPHABETIC_PRESENTATION_FORMS = [0xFB00, 0xFB4F];
    const ANATOLIAN_HIEROGLYPHS = [0x14400, 0x1467F];
    const ANCIENT_GREEK_MUSICAL_NOTATION = [0x1D200, 0x1D24F];
    const ANCIENT_GREEK_NUMBERS = [0x10140, 0x1018F];
    const ANCIENT_SYMBOLS = [0x10190, 0x101CF];
    const ARABIC = [0x0600, 0x06FF];
    const ARABIC_EXTENDED_A = [0x08A0, 0x08FF];
    const ARABIC_MATHEMATICAL_ALPHABETIC_SYMBOLS = [0x1EE00, 0x1EEFF];
    const ARABIC_PRESENTATION_FORMS_A = [0xFB50, 0xFDFF];
    const ARABIC_PRESENTATION_FORMS_B = [0xFE70, 0xFEFF];
    const ARABIC_SUPPLEMENT = [0x0750, 0x077F];
    const ARMENIAN = [0x0530, 0x058F];
    const ARROWS = [0x2190, 0x21FF];
    const AVESTAN = [0x10B00, 0x10B3F];
    const BALINESE = [0x1B00, 0x1B7F];
    const BAMUM = [0xA6A0, 0xA6FF];
    const BAMUM_SUPPLEMENT = [0x16800, 0x16A3F];
    const BASIC_LATIN = [0x0000, 0x007F];
    const BASSA_VAH = [0x16AD0, 0x16AFF];
    const BATAK = [0x1BC0, 0x1BFF];
    const BENGALI = [0x0980, 0x09FF];
    const BHAIKSUKI = [0x11C00, 0x11C6F];
    const BLOCK_ELEMENTS = [0x2580, 0x259F];
    const BOPOMOFO = [0x3100, 0x312F];
    const BOPOMOFO_EXTENDED = [0x31A0, 0x31BF];
    const BOX_DRAWING = [0x2500, 0x257F];
    const BRAHMI = [0x11000, 0x1107F];
    const BRAILLE_PATTERNS = [0x2800, 0x28FF];
    const BUGINESE = [0x1A00, 0x1A1F];
    const BUHID = [0x1740, 0x175F];
    const BYZANTINE_MUSICAL_SYMBOLS = [0x1D000, 0x1D0FF];
    const CARIAN = [0x102A0, 0x102DF];
    const CAUCASIAN_ALBANIAN = [0x10530, 0x1056F];
    const CHAKMA = [0x11100, 0x1114F];
    const CHAM = [0xAA00, 0xAA5F];
    const CHEROKEE = [0x13A0, 0x13FF];
    const CHEROKEE_SUPPLEMENT = [0xAB70, 0xABBF];
    const CJK_COMPATIBILITY = [0x3300, 0x33FF];
    const CJK_COMPATIBILITY_FORMS = [0xFE30, 0xFE4F];
    const CJK_COMPATIBILITY_IDEOGRAPHS = [0xF900, 0xFAFF];
    const CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT = [0x2F800, 0x2FA1F];
    const CJK_RADICALS_SUPPLEMENT = [0x2E80, 0x2EFF];
    const CJK_STROKES = [0x31C0, 0x31EF];
    const CJK_SYMBOLS_AND_PUNCTUATION = [0x3000, 0x303F];
    const CJK_UNIFIED_IDEOGRAPHS = [0x4E00, 0x9FFF];
    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A = [0x3400, 0x4DBF];
    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B = [0x20000, 0x2A6DF];
    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C = [0x2A700, 0x2B73F];
    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D = [0x2B740, 0x2B81F];
    const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E = [0x2B820, 0x2CEAF];
    const COMBINING_DIACRITICAL_MARKS = [0x0300, 0x036F];
    const COMBINING_DIACRITICAL_MARKS_EXTENDED = [0x1AB0, 0x1AFF];
    const COMBINING_DIACRITICAL_MARKS_FOR_SYMBOLS = [0x20D0, 0x20FF];
    const COMBINING_DIACRITICAL_MARKS_SUPPLEMENT = [0x1DC0, 0x1DFF];
    const COMBINING_HALF_MARKS = [0xFE20, 0xFE2F];
    const COMMON_INDIC_NUMBER_FORMS = [0xA830, 0xA83F];
    const CONTROL_PICTURES = [0x2400, 0x243F];
    const COPTIC = [0x2C80, 0x2CFF];
    const COPTIC_EPACT_NUMBERS = [0x102E0, 0x102FF];
    const COUNTING_ROD_NUMERALS = [0x1D360, 0x1D37F];
    const CUNEIFORM = [0x12000, 0x123FF];
    const CUNEIFORM_NUMBERS_AND_PUNCTUATION = [0x12400, 0x1247F];
    const CURRENCY_SYMBOLS = [0x20A0, 0x20CF];
    const CYPRIOT_SYLLABARY = [0x10800, 0x1083F];
    const CYRILLIC = [0x0400, 0x04FF];
    const CYRILLIC_EXTENDED_A = [0x2DE0, 0x2DFF];
    const CYRILLIC_EXTENDED_B = [0xA640, 0xA69F];
    const CYRILLIC_EXTENDED_C = [0x1C80, 0x1C8F];
    const CYRILLIC_SUPPLEMENT = [0x0500, 0x052F];
    const DESERET = [0x10400, 0x1044F];
    const DEVANAGARI = [0x0900, 0x097F];
    const DEVANAGARI_EXTENDED = [0xA8E0, 0xA8FF];
    const DINGBATS = [0x2700, 0x27BF];
    const DOMINO_TILES = [0x1F030, 0x1F09F];
    const DUPLOYAN = [0x1BC00, 0x1BC9F];
    const EARLY_DYNASTIC_CUNEIFORM = [0x12480, 0x1254F];
    const EGYPTIAN_HIEROGLYPHS = [0x13000, 0x1342F];
    const ELBASAN = [0x10500, 0x1052F];
    const EMOTICONS = [0x1F600, 0x1F64F];
    const ENCLOSED_ALPHANUMERICS = [0x2460, 0x24FF];
    const ENCLOSED_ALPHANUMERIC_SUPPLEMENT = [0x1F100, 0x1F1FF];
    const ENCLOSED_CJK_LETTERS_AND_MONTHS = [0x3200, 0x32FF];
    const ENCLOSED_IDEOGRAPHIC_SUPPLEMENT = [0x1F200, 0x1F2FF];
    const ETHIOPIC = [0x1200, 0x137F];
    const ETHIOPIC_EXTENDED = [0x2D80, 0x2DDF];
    const ETHIOPIC_EXTENDED_A = [0xAB00, 0xAB2F];
    const ETHIOPIC_SUPPLEMENT = [0x1380, 0x139F];
    const GENERAL_PUNCTUATION = [0x2000, 0x206F];
    const GEOMETRIC_SHAPES = [0x25A0, 0x25FF];
    const GEOMETRIC_SHAPES_EXTENDED = [0x1F780, 0x1F7FF];
    const GEORGIAN = [0x10A0, 0x10FF];
    const GEORGIAN_SUPPLEMENT = [0x2D00, 0x2D2F];
    const GLAGOLITIC = [0x2C00, 0x2C5F];
    const GLAGOLITIC_SUPPLEMENT = [0x1E000, 0x1E02F];
    const GOTHIC = [0x10330, 0x1034F];
    const GRANTHA = [0x11300, 0x1137F];
    const GREEK_AND_COPTIC = [0x0370, 0x03FF];
    const GREEK_EXTENDED = [0x1F00, 0x1FFF];
    const GUJARATI = [0x0A80, 0x0AFF];
    const GURMUKHI = [0x0A00, 0x0A7F];
    const HALFWIDTH_AND_FULLWIDTH_FORMS = [0xFF00, 0xFFEF];
    const HANGUL_COMPATIBILITY_JAMO = [0x3130, 0x318F];
    const HANGUL_JAMO = [0x1100, 0x11FF];
    const HANGUL_JAMO_EXTENDED_A = [0xA960, 0xA97F];
    const HANGUL_JAMO_EXTENDED_B = [0xD7B0, 0xD7FF];
    const HANGUL_SYLLABLES = [0xAC00, 0xD7AF];
    const HANUNOO = [0x1720, 0x173F];
    const HATRAN = [0x108E0, 0x108FF];
    const HEBREW = [0x0590, 0x05FF];
    const HIGH_PRIVATE_USE_SURROGATES = [0xDB80, 0xDBFF];
    const HIGH_SURROGATES = [0xD800, 0xDB7F];
    const HIRAGANA = [0x3040, 0x309F];
    const IDEOGRAPHIC_DESCRIPTION_CHARACTERS = [0x2FF0, 0x2FFF];
    const IDEOGRAPHIC_SYMBOLS_AND_PUNCTUATION = [0x16FE0, 0x16FFF];
    const IMPERIAL_ARAMAIC = [0x10840, 0x1085F];
    const INSCRIPTIONAL_PAHLAVI = [0x10B60, 0x10B7F];
    const INSCRIPTIONAL_PARTHIAN = [0x10B40, 0x10B5F];
    const IPA_EXTENSIONS = [0x0250, 0x02AF];
    const JAVANESE = [0xA980, 0xA9DF];
    const KAITHI = [0x11080, 0x110CF];
    const KANA_SUPPLEMENT = [0x1B000, 0x1B0FF];
    const KANBUN = [0x3190, 0x319F];
    const KANGXI_RADICALS = [0x2F00, 0x2FDF];
    const KANNADA = [0x0C80, 0x0CFF];
    const KATAKANA = [0x30A0, 0x30FF];
    const KATAKANA_PHONETIC_EXTENSIONS = [0x31F0, 0x31FF];
    const KAYAH_LI = [0xA900, 0xA92F];
    const KHAROSHTHI = [0x10A00, 0x10A5F];
    const KHMER = [0x1780, 0x17FF];
    const KHMER_SYMBOLS = [0x19E0, 0x19FF];
    const KHOJKI = [0x11200, 0x1124F];
    const KHUDAWADI = [0x112B0, 0x112FF];
    const LAO = [0x0E80, 0x0EFF];
    const LATIN_1_SUPPLEMENT = [0x0080, 0x00FF];
    const LATIN_EXTENDED_A = [0x0100, 0x017F];
    const LATIN_EXTENDED_ADDITIONAL = [0x1E00, 0x1EFF];
    const LATIN_EXTENDED_B = [0x0180, 0x024F];
    const LATIN_EXTENDED_C = [0x2C60, 0x2C7F];
    const LATIN_EXTENDED_D = [0xA720, 0xA7FF];
    const LATIN_EXTENDED_E = [0xAB30, 0xAB6F];
    const LEPCHA = [0x1C00, 0x1C4F];
    const LETTERLIKE_SYMBOLS = [0x2100, 0x214F];
    const LIMBU = [0x1900, 0x194F];
    const LINEAR_A = [0x10600, 0x1077F];
    const LINEAR_B_IDEOGRAMS = [0x10080, 0x100FF];
    const LINEAR_B_SYLLABARY = [0x10000, 0x1007F];
    const LISU = [0xA4D0, 0xA4FF];
    const LOW_SURROGATES = [0xDC00, 0xDFFF];
    const LYCIAN = [0x10280, 0x1029F];
    const LYDIAN = [0x10920, 0x1093F];
    const MAHAJANI = [0x11150, 0x1117F];
    const MAHJONG_TILES = [0x1F000, 0x1F02F];
    const MALAYALAM = [0x0D00, 0x0D7F];
    const MANDAIC = [0x0840, 0x085F];
    const MANICHAEAN = [0x10AC0, 0x10AFF];
    const MARCHEN = [0x11C70, 0x11CBF];
    const MATHEMATICAL_ALPHANUMERIC_SYMBOLS = [0x1D400, 0x1D7FF];
    const MATHEMATICAL_OPERATORS = [0x2200, 0x22FF];
    const MEETEI_MAYEK = [0xABC0, 0xABFF];
    const MEETEI_MAYEK_EXTENSIONS = [0xAAE0, 0xAAFF];
    const MENDE_KIKAKUI = [0x1E800, 0x1E8DF];
    const MEROITIC_CURSIVE = [0x109A0, 0x109FF];
    const MEROITIC_HIEROGLYPHS = [0x10980, 0x1099F];
    const MIAO = [0x16F00, 0x16F9F];
    const MISCELLANEOUS_MATHEMATICAL_SYMBOLS_A = [0x27C0, 0x27EF];
    const MISCELLANEOUS_MATHEMATICAL_SYMBOLS_B = [0x2980, 0x29FF];
    const MISCELLANEOUS_SYMBOLS = [0x2600, 0x26FF];
    const MISCELLANEOUS_SYMBOLS_AND_ARROWS = [0x2B00, 0x2BFF];
    const MISCELLANEOUS_SYMBOLS_AND_PICTOGRAPHS = [0x1F300, 0x1F5FF];
    const MISCELLANEOUS_TECHNICAL = [0x2300, 0x23FF];
    const MODI = [0x11600, 0x1165F];
    const MODIFIER_TONE_LETTERS = [0xA700, 0xA71F];
    const MONGOLIAN = [0x1800, 0x18AF];
    const MONGOLIAN_SUPPLEMENT = [0x11660, 0x1167F];
    const MRO = [0x16A40, 0x16A6F];
    const MULTANI = [0x11280, 0x112AF];
    const MUSICAL_SYMBOLS = [0x1D100, 0x1D1FF];
    const MYANMAR = [0x1000, 0x109F];
    const MYANMAR_EXTENDED_A = [0xAA60, 0xAA7F];
    const MYANMAR_EXTENDED_B = [0xA9E0, 0xA9FF];
    const NABATAEAN = [0x10880, 0x108AF];
    const NEWA = [0x11400, 0x1147F];
    const NEW_TAI_LUE = [0x1980, 0x19DF];
    const NKO = [0x07C0, 0x07FF];
    const NUMBER_FORMS = [0x2150, 0x218F];
    const OGHAM = [0x1680, 0x169F];
    const OLD_HUNGARIAN = [0x10C80, 0x10CFF];
    const OLD_ITALIC = [0x10300, 0x1032F];
    const OLD_NORTH_ARABIAN = [0x10A80, 0x10A9F];
    const OLD_PERMIC = [0x10350, 0x1037F];
    const OLD_PERSIAN = [0x103A0, 0x103DF];
    const OLD_SOUTH_ARABIAN = [0x10A60, 0x10A7F];
    const OLD_TURKIC = [0x10C00, 0x10C4F];
    const OL_CHIKI = [0x1C50, 0x1C7F];
    const OPTICAL_CHARACTER_RECOGNITION = [0x2440, 0x245F];
    const ORIYA = [0x0B00, 0x0B7F];
    const ORNAMENTAL_DINGBATS = [0x1F650, 0x1F67F];
    const OSAGE = [0x104B0, 0x104FF];
    const OSMANYA = [0x10480, 0x104AF];
    const PAHAWH_HMONG = [0x16B00, 0x16B8F];
    const PALMYRENE = [0x10860, 0x1087F];
    const PAU_CIN_HAU = [0x11AC0, 0x11AFF];
    const PHAGS_PA = [0xA840, 0xA87F];
    const PHAISTOS_DISC = [0x101D0, 0x101FF];
    const PHOENICIAN = [0x10900, 0x1091F];
    const PHONETIC_EXTENSIONS = [0x1D00, 0x1D7F];
    const PHONETIC_EXTENSIONS_SUPPLEMENT = [0x1D80, 0x1DBF];
    const PLAYING_CARDS = [0x1F0A0, 0x1F0FF];
    const PRIVATE_USE_AREA = [0xE000, 0xF8FF];
    const PSALTER_PAHLAVI = [0x10B80, 0x10BAF];
    const REJANG = [0xA930, 0xA95F];
    const RUMI_NUMERAL_SYMBOLS = [0x10E60, 0x10E7F];
    const RUNIC = [0x16A0, 0x16FF];
    const SAMARITAN = [0x0800, 0x083F];
    const SAURASHTRA = [0xA880, 0xA8DF];
    const SHARADA = [0x11180, 0x111DF];
    const SHAVIAN = [0x10450, 0x1047F];
    const SHORTHAND_FORMAT_CONTROLS = [0x1BCA0, 0x1BCAF];
    const SIDDHAM = [0x11580, 0x115FF];
    const SINHALA = [0x0D80, 0x0DFF];
    const SINHALA_ARCHAIC_NUMBERS = [0x111E0, 0x111FF];
    const SMALL_FORM_VARIANTS = [0xFE50, 0xFE6F];
    const SORA_SOMPENG = [0x110D0, 0x110FF];
    const SPACING_MODIFIER_LETTERS = [0x02B0, 0x02FF];
    const SPECIALS = [0xFFF0, 0xFFFF];
    const SUNDANESE = [0x1B80, 0x1BBF];
    const SUNDANESE_SUPPLEMENT = [0x1CC0, 0x1CCF];
    const SUPERSCRIPTS_AND_SUBSCRIPTS = [0x2070, 0x209F];
    const SUPPLEMENTAL_ARROWS_A = [0x27F0, 0x27FF];
    const SUPPLEMENTAL_ARROWS_B = [0x2900, 0x297F];
    const SUPPLEMENTAL_ARROWS_C = [0x1F800, 0x1F8FF];
    const SUPPLEMENTAL_MATHEMATICAL_OPERATORS = [0x2A00, 0x2AFF];
    const SUPPLEMENTAL_PUNCTUATION = [0x2E00, 0x2E7F];
    const SUPPLEMENTAL_SYMBOLS_AND_PICTOGRAPHS = [0x1F900, 0x1F9FF];
    const SUPPLEMENTARY_PRIVATE_USE_AREA_A = [0xF0000, 0xFFFFF];
    const SUPPLEMENTARY_PRIVATE_USE_AREA_B = [0x100000, 0x10FFFF];
    const SUTTON_SIGNWRITING = [0x1D800, 0x1DAAF];
    const SYLOTI_NAGRI = [0xA800, 0xA82F];
    const SYRIAC = [0x0700, 0x074F];
    const TAGALOG = [0x1700, 0x171F];
    const TAGBANWA = [0x1760, 0x177F];
    const TAGS = [0xE0000, 0xE007F];
    const TAI_LE = [0x1950, 0x197F];
    const TAI_THAM = [0x1A20, 0x1AAF];
    const TAI_VIET = [0xAA80, 0xAADF];
    const TAI_XUAN_JING_SYMBOLS = [0x1D300, 0x1D35F];
    const TAKRI = [0x11680, 0x116CF];
    const TAMIL = [0x0B80, 0x0BFF];
    const TANGUT = [0x17000, 0x187FF];
    const TANGUT_COMPONENTS = [0x18800, 0x18AFF];
    const TELUGU = [0x0C00, 0x0C7F];
    const THAANA = [0x0780, 0x07BF];
    const THAI = [0x0E00, 0x0E7F];
    const TIBETAN = [0x0F00, 0x0FFF];
    const TIFINAGH = [0x2D30, 0x2D7F];
    const TIRHUTA = [0x11480, 0x114DF];
    const TRANSPORT_AND_MAP_SYMBOLS = [0x1F680, 0x1F6FF];
    const UGARITIC = [0x10380, 0x1039F];
    const UNIFIED_CANADIAN_ABORIGINAL_SYLLABICS = [0x1400, 0x167F];
    const UNIFIED_CANADIAN_ABORIGINAL_SYLLABICS_EXTENDED = [0x18B0, 0x18FF];
    const VAI = [0xA500, 0xA63F];
    const VARIATION_SELECTORS = [0xFE00, 0xFE0F];
    const VARIATION_SELECTORS_SUPPLEMENT = [0xE0100, 0xE01EF];
    const VEDIC_EXTENSIONS = [0x1CD0, 0x1CFF];
    const VERTICAL_FORMS = [0xFE10, 0xFE1F];
    const WARANG_CITI = [0x118A0, 0x118FF];
    const YIJING_HEXAGRAM_SYMBOLS = [0x4DC0, 0x4DFF];
    const YI_RADICALS = [0xA490, 0xA4CF];
    const YI_SYLLABLES = [0xA000, 0xA48F];

    /** @var string $block The Unicode character block to check against */
    private $blocks = [];

    /**
     * Ojbect constructor
     *
     * Can be passed one or more of the following:
     * * a constant defining a Unicode character block
     * * a string containing the name of a constant
     * * an array containing start and end code points in numeric form
     *
     * @param string|int[] ...$blocks The block(s) to check against
     * @return void
     * @throws \Exception if an invalid block is passed
     */
    public function __construct(...$blocks)
    {
        foreach ($blocks as $block) {
            if (is_string($block) && defined("self::$block")) {
                $this->blocks[] = constant("self::$block");
            } elseif (!is_array($block) || $block[1] < $block[0]) {
                throw new \Exception("Bad character range passed!");
            } else {
                $this->blocks[] = $block;
            }
        }
    }

    /**
     * Adds a block to the existing list
     *
     * @param string|int[] $block The block to add (see constructor for details)
     * @return void
     * @throws \Exception if an invalid block is passed
     */
    public function addBlock($block)
    {
        if (is_string($block) && defined("self::$block")) {
            $this->blocks[] = constant("self::$block");
        } elseif (!is_array($block) || $block[1] < $block[0]) {
            throw new \Exception("Bad character range passed!");
        } else {
            $this->blocks[] = $block;
        }
    }

    /**
     * Checks if the given string is composed only of characters in the defined block(s)
     *
     * @param string $string The string to check
     * @return boolean
     */
    public function check($string)
    {
        if (empty($string)) {
            return true;
        }
        $pattern = "/^[";
        foreach ($this->blocks as $block) {
            $st = dechex($block[0]);
            $fi = dechex($block[1]);
            // note double braces to get literal braces in expression
            $pattern .= "\x{{$st}}-\x{{$fi}}";
        }
        $pattern .= "]*$/u";
        return (boolean)preg_match($pattern, $string);
    }

    /**
     * Static method to check if the string is composed only of characters in a block
     *
     * @param string $string The string to check
     * @param string|int[] $block The block to check against (see constructor for details)
     * @return boolean
     * @throws \Exception if an invalid block is passed
     */
    public static function isValid($string, $block)
    {
        if (empty($string)) {
            return true;
        } elseif (is_string($block) && defined("self::$block")) {
            $block = constant("self::$block");
        } elseif (!is_array($block) || $block[1] < $block[0]) {
            throw new Exception("Bad character range passed!");
        }
        $st = dechex($block[0]);
        $fi = dechex($block[1]);
        // note double braces to get literal braces in expression
        $pattern = "/^[\x{{$st}}-\x{{$fi}}]*$/u";
        return (boolean)preg_match($pattern, $string);
    }
 }
	<?php
	/**
	* BlockCheck 1.0
	*
	* Copyright (C) 2017 Michael Newton
	*
	* This program is free software: you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation, either version 3 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*
	* @package BlockCheck
	* @author Michael Newton <miken32>
	* @copyright 2017 Michael Newton
	* @license https://opensource.org/licenses/GPL-3.0 GPLv3
	* @version 1.0
	* @see http://stackoverflow.com/a/43010755/1255289
	*/

	namespace Miken32;

	/**
	* BlockCheck
	*
	* A utility class to check whether or not strings are part of
	* a Unicode character block.
	*
	* Can be used statically or not. Sample usage:
	* ```
	* <?php
	* use Miken32\BlockCheck as BC;
	* if (BC::isValid("🜈🝮🝤", BC::ALCHEMICAL_SYMBOLS)) {
	* echo "Valid characters\n";
	* } else {
	* echo "Invalid characters\n";
	* }
	*
	* $myChecker = new BC("BASIC_LATIN");
	* $test = "Meet me at the café.";
	* if ($myChecker->check($test)) {
	* echo "Valid characters\n";
	* } else {
	* echo "Invalid characters\n";
	* }
	* $myChecker->addBlock(BC::LATIN_1_SUPPLEMENT);
	* if ($myChecker->check($test)) {
	* echo "Valid characters\n";
	* } else {
	* echo "Invalid characters\n";
	* }
	* ```
	*/
	class BlockCheck
	{
	const ADLAM = [0x1E900, 0x1E95F];
	const AEGEAN_NUMBERS = [0x10100, 0x1013F];
	const AHOM = [0x11700, 0x1173F];
	const ALCHEMICAL_SYMBOLS = [0x1F700, 0x1F77F];
	const ALPHABETIC_PRESENTATION_FORMS = [0xFB00, 0xFB4F];
	const ANATOLIAN_HIEROGLYPHS = [0x14400, 0x1467F];
	const ANCIENT_GREEK_MUSICAL_NOTATION = [0x1D200, 0x1D24F];
	const ANCIENT_GREEK_NUMBERS = [0x10140, 0x1018F];
	const ANCIENT_SYMBOLS = [0x10190, 0x101CF];
	const ARABIC = [0x0600, 0x06FF];
	const ARABIC_EXTENDED_A = [0x08A0, 0x08FF];
	const ARABIC_MATHEMATICAL_ALPHABETIC_SYMBOLS = [0x1EE00, 0x1EEFF];
	const ARABIC_PRESENTATION_FORMS_A = [0xFB50, 0xFDFF];
	const ARABIC_PRESENTATION_FORMS_B = [0xFE70, 0xFEFF];
	const ARABIC_SUPPLEMENT = [0x0750, 0x077F];
	const ARMENIAN = [0x0530, 0x058F];
	const ARROWS = [0x2190, 0x21FF];
	const AVESTAN = [0x10B00, 0x10B3F];
	const BALINESE = [0x1B00, 0x1B7F];
	const BAMUM = [0xA6A0, 0xA6FF];
	const BAMUM_SUPPLEMENT = [0x16800, 0x16A3F];
	const BASIC_LATIN = [0x0000, 0x007F];
	const BASSA_VAH = [0x16AD0, 0x16AFF];
	const BATAK = [0x1BC0, 0x1BFF];
	const BENGALI = [0x0980, 0x09FF];
	const BHAIKSUKI = [0x11C00, 0x11C6F];
	const BLOCK_ELEMENTS = [0x2580, 0x259F];
	const BOPOMOFO = [0x3100, 0x312F];
	const BOPOMOFO_EXTENDED = [0x31A0, 0x31BF];
	const BOX_DRAWING = [0x2500, 0x257F];
	const BRAHMI = [0x11000, 0x1107F];
	const BRAILLE_PATTERNS = [0x2800, 0x28FF];
	const BUGINESE = [0x1A00, 0x1A1F];
	const BUHID = [0x1740, 0x175F];
	const BYZANTINE_MUSICAL_SYMBOLS = [0x1D000, 0x1D0FF];
	const CARIAN = [0x102A0, 0x102DF];
	const CAUCASIAN_ALBANIAN = [0x10530, 0x1056F];
	const CHAKMA = [0x11100, 0x1114F];
	const CHAM = [0xAA00, 0xAA5F];
	const CHEROKEE = [0x13A0, 0x13FF];
	const CHEROKEE_SUPPLEMENT = [0xAB70, 0xABBF];
	const CJK_COMPATIBILITY = [0x3300, 0x33FF];
	const CJK_COMPATIBILITY_FORMS = [0xFE30, 0xFE4F];
	const CJK_COMPATIBILITY_IDEOGRAPHS = [0xF900, 0xFAFF];
	const CJK_COMPATIBILITY_IDEOGRAPHS_SUPPLEMENT = [0x2F800, 0x2FA1F];
	const CJK_RADICALS_SUPPLEMENT = [0x2E80, 0x2EFF];
	const CJK_STROKES = [0x31C0, 0x31EF];
	const CJK_SYMBOLS_AND_PUNCTUATION = [0x3000, 0x303F];
	const CJK_UNIFIED_IDEOGRAPHS = [0x4E00, 0x9FFF];
	const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A = [0x3400, 0x4DBF];
	const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B = [0x20000, 0x2A6DF];
	const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_C = [0x2A700, 0x2B73F];
	const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_D = [0x2B740, 0x2B81F];
	const CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E = [0x2B820, 0x2CEAF];
	const COMBINING_DIACRITICAL_MARKS = [0x0300, 0x036F];
	const COMBINING_DIACRITICAL_MARKS_EXTENDED = [0x1AB0, 0x1AFF];
	const COMBINING_DIACRITICAL_MARKS_FOR_SYMBOLS = [0x20D0, 0x20FF];
	const COMBINING_DIACRITICAL_MARKS_SUPPLEMENT = [0x1DC0, 0x1DFF];
	const COMBINING_HALF_MARKS = [0xFE20, 0xFE2F];
	const COMMON_INDIC_NUMBER_FORMS = [0xA830, 0xA83F];
	const CONTROL_PICTURES = [0x2400, 0x243F];
	const COPTIC = [0x2C80, 0x2CFF];
	const COPTIC_EPACT_NUMBERS = [0x102E0, 0x102FF];
	const COUNTING_ROD_NUMERALS = [0x1D360, 0x1D37F];
	const CUNEIFORM = [0x12000, 0x123FF];
	const CUNEIFORM_NUMBERS_AND_PUNCTUATION = [0x12400, 0x1247F];
	const CURRENCY_SYMBOLS = [0x20A0, 0x20CF];
	const CYPRIOT_SYLLABARY = [0x10800, 0x1083F];
	const CYRILLIC = [0x0400, 0x04FF];
	const CYRILLIC_EXTENDED_A = [0x2DE0, 0x2DFF];
	const CYRILLIC_EXTENDED_B = [0xA640, 0xA69F];
	const CYRILLIC_EXTENDED_C = [0x1C80, 0x1C8F];
	const CYRILLIC_SUPPLEMENT = [0x0500, 0x052F];
	const DESERET = [0x10400, 0x1044F];
	const DEVANAGARI = [0x0900, 0x097F];
	const DEVANAGARI_EXTENDED = [0xA8E0, 0xA8FF];
	const DINGBATS = [0x2700, 0x27BF];
	const DOMINO_TILES = [0x1F030, 0x1F09F];
	const DUPLOYAN = [0x1BC00, 0x1BC9F];
	const EARLY_DYNASTIC_CUNEIFORM = [0x12480, 0x1254F];
	const EGYPTIAN_HIEROGLYPHS = [0x13000, 0x1342F];
	const ELBASAN = [0x10500, 0x1052F];
	const EMOTICONS = [0x1F600, 0x1F64F];
	const ENCLOSED_ALPHANUMERICS = [0x2460, 0x24FF];
	const ENCLOSED_ALPHANUMERIC_SUPPLEMENT = [0x1F100, 0x1F1FF];
	const ENCLOSED_CJK_LETTERS_AND_MONTHS = [0x3200, 0x32FF];
	const ENCLOSED_IDEOGRAPHIC_SUPPLEMENT = [0x1F200, 0x1F2FF];
	const ETHIOPIC = [0x1200, 0x137F];
	const ETHIOPIC_EXTENDED = [0x2D80, 0x2DDF];
	const ETHIOPIC_EXTENDED_A = [0xAB00, 0xAB2F];
	const ETHIOPIC_SUPPLEMENT = [0x1380, 0x139F];
	const GENERAL_PUNCTUATION = [0x2000, 0x206F];
	const GEOMETRIC_SHAPES = [0x25A0, 0x25FF];
	const GEOMETRIC_SHAPES_EXTENDED = [0x1F780, 0x1F7FF];
	const GEORGIAN = [0x10A0, 0x10FF];
	const GEORGIAN_SUPPLEMENT = [0x2D00, 0x2D2F];
	const GLAGOLITIC = [0x2C00, 0x2C5F];
	const GLAGOLITIC_SUPPLEMENT = [0x1E000, 0x1E02F];
	const GOTHIC = [0x10330, 0x1034F];
	const GRANTHA = [0x11300, 0x1137F];
	const GREEK_AND_COPTIC = [0x0370, 0x03FF];
	const GREEK_EXTENDED = [0x1F00, 0x1FFF];
	const GUJARATI = [0x0A80, 0x0AFF];
	const GURMUKHI = [0x0A00, 0x0A7F];
	const HALFWIDTH_AND_FULLWIDTH_FORMS = [0xFF00, 0xFFEF];
	const HANGUL_COMPATIBILITY_JAMO = [0x3130, 0x318F];
	const HANGUL_JAMO = [0x1100, 0x11FF];
	const HANGUL_JAMO_EXTENDED_A = [0xA960, 0xA97F];
	const HANGUL_JAMO_EXTENDED_B = [0xD7B0, 0xD7FF];
	const HANGUL_SYLLABLES = [0xAC00, 0xD7AF];
	const HANUNOO = [0x1720, 0x173F];
	const HATRAN = [0x108E0, 0x108FF];
	const HEBREW = [0x0590, 0x05FF];
	const HIGH_PRIVATE_USE_SURROGATES = [0xDB80, 0xDBFF];
	const HIGH_SURROGATES = [0xD800, 0xDB7F];
	const HIRAGANA = [0x3040, 0x309F];
	const IDEOGRAPHIC_DESCRIPTION_CHARACTERS = [0x2FF0, 0x2FFF];
	const IDEOGRAPHIC_SYMBOLS_AND_PUNCTUATION = [0x16FE0, 0x16FFF];
	const IMPERIAL_ARAMAIC = [0x10840, 0x1085F];
	const INSCRIPTIONAL_PAHLAVI = [0x10B60, 0x10B7F];
	const INSCRIPTIONAL_PARTHIAN = [0x10B40, 0x10B5F];
	const IPA_EXTENSIONS = [0x0250, 0x02AF];
	const JAVANESE = [0xA980, 0xA9DF];
	const KAITHI = [0x11080, 0x110CF];
	const KANA_SUPPLEMENT = [0x1B000, 0x1B0FF];
	const KANBUN = [0x3190, 0x319F];
	const KANGXI_RADICALS = [0x2F00, 0x2FDF];
	const KANNADA = [0x0C80, 0x0CFF];
	const KATAKANA = [0x30A0, 0x30FF];
	const KATAKANA_PHONETIC_EXTENSIONS = [0x31F0, 0x31FF];
	const KAYAH_LI = [0xA900, 0xA92F];
	const KHAROSHTHI = [0x10A00, 0x10A5F];
	const KHMER = [0x1780, 0x17FF];
	const KHMER_SYMBOLS = [0x19E0, 0x19FF];
	const KHOJKI = [0x11200, 0x1124F];
	const KHUDAWADI = [0x112B0, 0x112FF];
	const LAO = [0x0E80, 0x0EFF];
	const LATIN_1_SUPPLEMENT = [0x0080, 0x00FF];
	const LATIN_EXTENDED_A = [0x0100, 0x017F];
	const LATIN_EXTENDED_ADDITIONAL = [0x1E00, 0x1EFF];
	const LATIN_EXTENDED_B = [0x0180, 0x024F];
	const LATIN_EXTENDED_C = [0x2C60, 0x2C7F];
	const LATIN_EXTENDED_D = [0xA720, 0xA7FF];
	const LATIN_EXTENDED_E = [0xAB30, 0xAB6F];
	const LEPCHA = [0x1C00, 0x1C4F];
	const LETTERLIKE_SYMBOLS = [0x2100, 0x214F];
	const LIMBU = [0x1900, 0x194F];
	const LINEAR_A = [0x10600, 0x1077F];
	const LINEAR_B_IDEOGRAMS = [0x10080, 0x100FF];
	const LINEAR_B_SYLLABARY = [0x10000, 0x1007F];
	const LISU = [0xA4D0, 0xA4FF];
	const LOW_SURROGATES = [0xDC00, 0xDFFF];
	const LYCIAN = [0x10280, 0x1029F];
	const LYDIAN = [0x10920, 0x1093F];
	const MAHAJANI = [0x11150, 0x1117F];
	const MAHJONG_TILES = [0x1F000, 0x1F02F];
	const MALAYALAM = [0x0D00, 0x0D7F];
	const MANDAIC = [0x0840, 0x085F];
	const MANICHAEAN = [0x10AC0, 0x10AFF];
	const MARCHEN = [0x11C70, 0x11CBF];
	const MATHEMATICAL_ALPHANUMERIC_SYMBOLS = [0x1D400, 0x1D7FF];
	const MATHEMATICAL_OPERATORS = [0x2200, 0x22FF];
	const MEETEI_MAYEK = [0xABC0, 0xABFF];
	const MEETEI_MAYEK_EXTENSIONS = [0xAAE0, 0xAAFF];
	const MENDE_KIKAKUI = [0x1E800, 0x1E8DF];
	const MEROITIC_CURSIVE = [0x109A0, 0x109FF];
	const MEROITIC_HIEROGLYPHS = [0x10980, 0x1099F];
	const MIAO = [0x16F00, 0x16F9F];
	const MISCELLANEOUS_MATHEMATICAL_SYMBOLS_A = [0x27C0, 0x27EF];
	const MISCELLANEOUS_MATHEMATICAL_SYMBOLS_B = [0x2980, 0x29FF];
	const MISCELLANEOUS_SYMBOLS = [0x2600, 0x26FF];
	const MISCELLANEOUS_SYMBOLS_AND_ARROWS = [0x2B00, 0x2BFF];
	const MISCELLANEOUS_SYMBOLS_AND_PICTOGRAPHS = [0x1F300, 0x1F5FF];
	const MISCELLANEOUS_TECHNICAL = [0x2300, 0x23FF];
	const MODI = [0x11600, 0x1165F];
	const MODIFIER_TONE_LETTERS = [0xA700, 0xA71F];
	const MONGOLIAN = [0x1800, 0x18AF];
	const MONGOLIAN_SUPPLEMENT = [0x11660, 0x1167F];
	const MRO = [0x16A40, 0x16A6F];
	const MULTANI = [0x11280, 0x112AF];
	const MUSICAL_SYMBOLS = [0x1D100, 0x1D1FF];
	const MYANMAR = [0x1000, 0x109F];
	const MYANMAR_EXTENDED_A = [0xAA60, 0xAA7F];
	const MYANMAR_EXTENDED_B = [0xA9E0, 0xA9FF];
	const NABATAEAN = [0x10880, 0x108AF];
	const NEWA = [0x11400, 0x1147F];
	const NEW_TAI_LUE = [0x1980, 0x19DF];
	const NKO = [0x07C0, 0x07FF];
	const NUMBER_FORMS = [0x2150, 0x218F];
	const OGHAM = [0x1680, 0x169F];
	const OLD_HUNGARIAN = [0x10C80, 0x10CFF];
	const OLD_ITALIC = [0x10300, 0x1032F];
	const OLD_NORTH_ARABIAN = [0x10A80, 0x10A9F];
	const OLD_PERMIC = [0x10350, 0x1037F];
	const OLD_PERSIAN = [0x103A0, 0x103DF];
	const OLD_SOUTH_ARABIAN = [0x10A60, 0x10A7F];
	const OLD_TURKIC = [0x10C00, 0x10C4F];
	const OL_CHIKI = [0x1C50, 0x1C7F];
	const OPTICAL_CHARACTER_RECOGNITION = [0x2440, 0x245F];
	const ORIYA = [0x0B00, 0x0B7F];
	const ORNAMENTAL_DINGBATS = [0x1F650, 0x1F67F];
	const OSAGE = [0x104B0, 0x104FF];
	const OSMANYA = [0x10480, 0x104AF];
	const PAHAWH_HMONG = [0x16B00, 0x16B8F];
	const PALMYRENE = [0x10860, 0x1087F];
	const PAU_CIN_HAU = [0x11AC0, 0x11AFF];
	const PHAGS_PA = [0xA840, 0xA87F];
	const PHAISTOS_DISC = [0x101D0, 0x101FF];
	const PHOENICIAN = [0x10900, 0x1091F];
	const PHONETIC_EXTENSIONS = [0x1D00, 0x1D7F];
	const PHONETIC_EXTENSIONS_SUPPLEMENT = [0x1D80, 0x1DBF];
	const PLAYING_CARDS = [0x1F0A0, 0x1F0FF];
	const PRIVATE_USE_AREA = [0xE000, 0xF8FF];
	const PSALTER_PAHLAVI = [0x10B80, 0x10BAF];
	const REJANG = [0xA930, 0xA95F];
	const RUMI_NUMERAL_SYMBOLS = [0x10E60, 0x10E7F];
	const RUNIC = [0x16A0, 0x16FF];
	const SAMARITAN = [0x0800, 0x083F];
	const SAURASHTRA = [0xA880, 0xA8DF];
	const SHARADA = [0x11180, 0x111DF];
	const SHAVIAN = [0x10450, 0x1047F];
	const SHORTHAND_FORMAT_CONTROLS = [0x1BCA0, 0x1BCAF];
	const SIDDHAM = [0x11580, 0x115FF];
	const SINHALA = [0x0D80, 0x0DFF];
	const SINHALA_ARCHAIC_NUMBERS = [0x111E0, 0x111FF];
	const SMALL_FORM_VARIANTS = [0xFE50, 0xFE6F];
	const SORA_SOMPENG = [0x110D0, 0x110FF];
	const SPACING_MODIFIER_LETTERS = [0x02B0, 0x02FF];
	const SPECIALS = [0xFFF0, 0xFFFF];
	const SUNDANESE = [0x1B80, 0x1BBF];
	const SUNDANESE_SUPPLEMENT = [0x1CC0, 0x1CCF];
	const SUPERSCRIPTS_AND_SUBSCRIPTS = [0x2070, 0x209F];
	const SUPPLEMENTAL_ARROWS_A = [0x27F0, 0x27FF];
	const SUPPLEMENTAL_ARROWS_B = [0x2900, 0x297F];
	const SUPPLEMENTAL_ARROWS_C = [0x1F800, 0x1F8FF];
	const SUPPLEMENTAL_MATHEMATICAL_OPERATORS = [0x2A00, 0x2AFF];
	const SUPPLEMENTAL_PUNCTUATION = [0x2E00, 0x2E7F];
	const SUPPLEMENTAL_SYMBOLS_AND_PICTOGRAPHS = [0x1F900, 0x1F9FF];
	const SUPPLEMENTARY_PRIVATE_USE_AREA_A = [0xF0000, 0xFFFFF];
	const SUPPLEMENTARY_PRIVATE_USE_AREA_B = [0x100000, 0x10FFFF];
	const SUTTON_SIGNWRITING = [0x1D800, 0x1DAAF];
	const SYLOTI_NAGRI = [0xA800, 0xA82F];
	const SYRIAC = [0x0700, 0x074F];
	const TAGALOG = [0x1700, 0x171F];
	const TAGBANWA = [0x1760, 0x177F];
	const TAGS = [0xE0000, 0xE007F];
	const TAI_LE = [0x1950, 0x197F];
	const TAI_THAM = [0x1A20, 0x1AAF];
	const TAI_VIET = [0xAA80, 0xAADF];
	const TAI_XUAN_JING_SYMBOLS = [0x1D300, 0x1D35F];
	const TAKRI = [0x11680, 0x116CF];
	const TAMIL = [0x0B80, 0x0BFF];
	const TANGUT = [0x17000, 0x187FF];
	const TANGUT_COMPONENTS = [0x18800, 0x18AFF];
	const TELUGU = [0x0C00, 0x0C7F];
	const THAANA = [0x0780, 0x07BF];
	const THAI = [0x0E00, 0x0E7F];
	const TIBETAN = [0x0F00, 0x0FFF];
	const TIFINAGH = [0x2D30, 0x2D7F];
	const TIRHUTA = [0x11480, 0x114DF];
	const TRANSPORT_AND_MAP_SYMBOLS = [0x1F680, 0x1F6FF];
	const UGARITIC = [0x10380, 0x1039F];
	const UNIFIED_CANADIAN_ABORIGINAL_SYLLABICS = [0x1400, 0x167F];
	const UNIFIED_CANADIAN_ABORIGINAL_SYLLABICS_EXTENDED = [0x18B0, 0x18FF];
	const VAI = [0xA500, 0xA63F];
	const VARIATION_SELECTORS = [0xFE00, 0xFE0F];
	const VARIATION_SELECTORS_SUPPLEMENT = [0xE0100, 0xE01EF];
	const VEDIC_EXTENSIONS = [0x1CD0, 0x1CFF];
	const VERTICAL_FORMS = [0xFE10, 0xFE1F];
	const WARANG_CITI = [0x118A0, 0x118FF];
	const YIJING_HEXAGRAM_SYMBOLS = [0x4DC0, 0x4DFF];
	const YI_RADICALS = [0xA490, 0xA4CF];
	const YI_SYLLABLES = [0xA000, 0xA48F];

	/** @var string $block The Unicode character block to check against */
	private $blocks = [];

	/**
	* Ojbect constructor
	*
	* Can be passed one or more of the following:
	* * a constant defining a Unicode character block
	* * a string containing the name of a constant
	* * an array containing start and end code points in numeric form
	*
	* @param string\|int[] ...$blocks The block(s) to check against
	* @return void
	* @throws \Exception if an invalid block is passed
	*/
	public function __construct(...$blocks)
	{
	foreach ($blocks as $block) {
	if (is_string($block) && defined("self::$block")) {
	$this->blocks[] = constant("self::$block");
	} elseif (!is_array($block) \|\| $block[1] < $block[0]) {
	throw new \Exception("Bad character range passed!");
	} else {
	$this->blocks[] = $block;
	}
	}
	}

	/**
	* Adds a block to the existing list
	*
	* @param string\|int[] $block The block to add (see constructor for details)
	* @return void
	* @throws \Exception if an invalid block is passed
	*/
	public function addBlock($block)
	{
	if (is_string($block) && defined("self::$block")) {
	$this->blocks[] = constant("self::$block");
	} elseif (!is_array($block) \|\| $block[1] < $block[0]) {
	throw new \Exception("Bad character range passed!");
	} else {
	$this->blocks[] = $block;
	}
	}

	/**
	* Checks if the given string is composed only of characters in the defined block(s)
	*
	* @param string $string The string to check
	* @return boolean
	*/
	public function check($string)
	{
	if (empty($string)) {
	return true;
	}
	$pattern = "/^[";
	foreach ($this->blocks as $block) {
	$st = dechex($block[0]);
	$fi = dechex($block[1]);
	// note double braces to get literal braces in expression
	$pattern .= "\x{{$st}}-\x{{$fi}}";
	}
	$pattern .= "]*$/u";
	return (boolean)preg_match($pattern, $string);
	}

	/**
	* Static method to check if the string is composed only of characters in a block
	*
	* @param string $string The string to check
	* @param string\|int[] $block The block to check against (see constructor for details)
	* @return boolean
	* @throws \Exception if an invalid block is passed
	*/
	public static function isValid($string, $block)
	{
	if (empty($string)) {
	return true;
	} elseif (is_string($block) && defined("self::$block")) {
	$block = constant("self::$block");
	} elseif (!is_array($block) \|\| $block[1] < $block[0]) {
	throw new Exception("Bad character range passed!");
	}
	$st = dechex($block[0]);
	$fi = dechex($block[1]);
	// note double braces to get literal braces in expression
	$pattern = "/^[\x{{$st}}-\x{{$fi}}]*$/u";
	return (boolean)preg_match($pattern, $string);
	}
	}