create whitespace tokenizer

src/Phpml/Tokenization/Tokenizer.php

@@ -0,0 +1,15 @@
+<?php
+
+declare (strict_types = 1);
+
+namespace Phpml\Tokenization;
+
+interface Tokenizer
+{
+    /**
+     * @param string $text
+     * 
+     * @return array
+     */
+    public function tokenize(string $text): array;
+}

src/Phpml/Tokenization/WhitespaceTokenizer.php

@@ -0,0 +1,18 @@
+<?php
+
+declare (strict_types = 1);
+
+namespace Phpml\Tokenization;
+
+class WhitespaceTokenizer implements Tokenizer
+{
+    /**
+     * @param string $text
+     *
+     * @return array
+     */
+    public function tokenize(string $text): array
+    {
+        return preg_split('/[\pZ\pC]+/u', $text, -1, PREG_SPLIT_NO_EMPTY);
+    }
+}

tests/Phpml/Tokenization/WhitespaceTokenizerTest.php

@@ -0,0 +1,40 @@
+<?php
+
+declare (strict_types = 1);
+
+namespace tests\Tokenization;
+
+use Phpml\Tokenization\WhitespaceTokenizer;
+
+class WhitespaceTokenizerTest extends \PHPUnit_Framework_TestCase
+{
+    public function testTokenizationOnAscii()
+    {
+        $tokenizer = new WhitespaceTokenizer();
+
+        $text = 'Lorem ipsum dolor sit amet, consectetur   adipiscing elit.
+                 Cras consectetur, dui et lobortis auctor. 
+                 Nulla vitae  congue lorem.';
+
+        $tokens = ['Lorem', 'ipsum', 'dolor', 'sit', 'amet,', 'consectetur', 'adipiscing', 'elit.',
+                 'Cras', 'consectetur,', 'dui', 'et', 'lobortis', 'auctor.',
+                 'Nulla', 'vitae', 'congue', 'lorem.', ];
+
+        $this->assertEquals($tokens, $tokenizer->tokenize($text));
+    }
+
+    public function testTokenizationOnUtf8()
+    {
+        $tokenizer = new WhitespaceTokenizer();
+
+        $text = '鋍鞎 鳼 鞮鞢騉 袟袘觕, 炟砏 蒮 謺貙蹖 偢偣唲 蒛 箷箯緷 鑴鱱爧 覮轀,
+                 剆坲 煘煓瑐 鬐鶤鶐 飹勫嫢 銪 餀 枲柊氠 鍎鞚韕 焲犈,
+                 殍涾烰 齞齝囃 蹅輶 鄜, 孻憵 擙樲橚 藒襓謥 岯岪弨 蒮 廞徲 孻憵懥 趡趛踠 槏';
+
+        $tokens = ['鋍鞎', '鳼', '鞮鞢騉', '袟袘觕,', '炟砏', '蒮', '謺貙蹖', '偢偣唲', '蒛', '箷箯緷', '鑴鱱爧', '覮轀,',
+                  '剆坲', '煘煓瑐', '鬐鶤鶐', '飹勫嫢', '銪', '餀', '枲柊氠', '鍎鞚韕', '焲犈,',
+                  '殍涾烰', '齞齝囃', '蹅輶', '鄜,', '孻憵', '擙樲橚', '藒襓謥', '岯岪弨', '蒮', '廞徲', '孻憵懥', '趡趛踠', '槏', ];
+
+        $this->assertEquals($tokens, $tokenizer->tokenize($text));
+    }
+}