[Utf8] added Bytes, CodePoints and Graphemes implementations.

Author: Hugo Hamon

src/Symfony/Component/Utf8/Bytes.php

@@ -0,0 +1,206 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Utf8;
+
+use Symfony\Component\Utf8\Exception\InvalidArgumentException;
+
+final class Bytes implements GenericStringInterface, \Countable
+{
+    private $string = '';
+
+    public static function fromString(string $string): self
+    {
+        $bytes = new self();
+        $bytes->string = $string;
+
+        return $bytes;
+    }
+
+    public static function fromCharCode(int ...$codes): self
+    {
+        $string = '';
+        foreach ($codes as $code) {
+            $string.= chr($code);
+        }
+
+        $bytes = new self();
+        $bytes->string = $string;
+
+        return $bytes;
+    }
+
+    public function __toString()
+    {
+        return $this->string;
+    }
+
+    /**
+     * @see \Countable::count
+     */
+    public function count(): int
+    {
+        return strlen($this->string);
+    }
+
+    public function length(): int
+    {
+        return strlen($this->string);
+    }
+
+    public function isEmpty(): bool
+    {
+        return '' === $this->string;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function explode(string $delimiter, int $limit = null): array
+    {
+        if ('' === $delimiter) {
+            throw new InvalidArgumentException('Passing an empty delimiter is not supported by this method. Use getIterator() method instead.');
+        }
+
+        $chunks = array();
+        foreach (explode($delimiter, $this->string, $limit ?: PHP_INT_MAX) as $i => $string) {
+            $chunks[$i] = $chunk = clone $this;
+            $chunk->string = $string;
+        }
+
+        return $chunks;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toLowerCase(): self
+    {
+        $result = clone $this;
+        $result->string = strtolower($this->string);
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toUpperCase(): self
+    {
+        $result = clone $this;
+        $result->string = strtoupper($this->string);
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function substr(int $start = 0, int $length = null): self
+    {
+        $result = clone $this;
+        $result->string = substr($this->string, $start, $length);
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function trim(string $charsList = null): self
+    {
+        $result = clone $this;
+        $result->string = trim($this->string, $charsList ?: " \t\n\r\0\x0B");
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function trimLeft(string $charsList = null): self
+    {
+        $result = clone $this;
+        $result->string = ltrim($this->string, $charsList ?: " \t\n\r\0\x0B");
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function trimRight(string $charsList = null): self
+    {
+        $result = clone $this;
+        $result->string = rtrim($this->string, $charsList ?: " \t\n\r\0\x0B");
+
+        return $result;
+    }
+
+    public function startsWith(string $prefix, int $offset = 0): bool
+    {
+        if ($offset < 0 && PHP_VERSION_ID < 70100) {
+            $offset = strlen($this->string) - abs($offset);
+        }
+
+        return $offset === strpos($this->string, $prefix, $offset);
+    }
+
+    public function endsWith(string $suffix): bool
+    {
+        $suffix = (string) $suffix;
+
+        return substr($this->string, -strlen($suffix)) === $suffix;
+    }
+
+    public function getIterator(int $maxChunkLength = 1): \Generator
+    {
+        if ($maxChunkLength < 1) {
+            throw new InvalidArgumentException('The maximum length of each segment must be greater than zero.');
+        }
+
+        if ('' === $this->string) {
+            yield clone $this;
+        }
+
+        foreach (str_split($this->string, $maxChunkLength) as $key => $char) {
+            $clone = clone $this;
+            $clone->string = $char;
+            yield $key => $clone;
+        }
+    }
+
+    public function append(string $suffix): self
+    {
+        $result = clone $this;
+        $result->string.= $suffix;
+
+        return $result;
+    }
+
+    public function prepend(string $prefix): self
+    {
+        $result = clone $this;
+        $result->string = $prefix.$result->string;
+
+        return $result;
+    }
+
+    public function toCodePoints(): CodePoints
+    {
+        return CodePoints::fromString($this->string);
+    }
+
+    public function toGraphemes(): Graphemes
+    {
+        return Graphemes::fromString($this->string);
+    }
+}