php-kilo/src/Row.php

<?php declare(strict_types=1);

namespace Kilo;

/**
 * @property-read int size
 * @property-read int rsize
 */
class Row {
	use MagicProperties;

	public string $chars = '';
	public string $render = '';

	// This feels dirty...
	private Editor $parent;

	public array $hl = [];

	public static function new(Editor $parent, string $chars): self
	{
		$self = new self();
		$self->chars = $chars;
		$self->parent = $parent;

		return $self;
	}

	private function __construct() {}

	public function __get(string $name)
	{
		switch ($name)
		{
			case 'size':
				return strlen($this->chars);

			case 'rsize':
				return strlen($this->render);

			default:
				return NULL;
		}
	}

	public function __toString(): string
	{
		return $this->chars . "\n";
	}

	public function insertChar(int $at, string $c): void
	{
		if ($at < 0 || $at > $this->size)
		{
			$at = $this->size;
		}

		// Safely insert into arbitrary position in the existing string
		$this->chars = substr($this->chars, 0, $at) . $c . substr($this->chars, $at);
		$this->update();

		$this->parent->dirty++;
	}

	public function appendString(string $s): void
	{
		$this->chars .= $s;
		$this->update();

		$this->parent->dirty++;
	}

	public function deleteChar(int $at): void
	{
		if ($at < 0 || $at >= $this->size)
		{
			return;
		}

		$this->chars = substr_replace($this->chars, '', $at, 1);
		$this->update();

		$this->parent->dirty++;
	}

	public function update(): void
	{
		$idx = 0;

		for ($i = 0; $i < $this->size; $i++)
		{
			if ($this->chars[$i] === "\t")
			{
				$this->render[$idx++] = ' ';
				while ($idx % KILO_TAB_STOP !== 0)
				{
					$this->render[$idx++] = ' ';
				}
			}
			else
			{
				$this->render[$idx++] = $this->chars[$i];
			}
		}

		$this->updateSyntax();
	}

	// ------------------------------------------------------------------------
	// ! Syntax Highlighting
	// ------------------------------------------------------------------------

	protected function updateSyntax(): void
	{
		$this->hl = array_fill(0, $this->rsize, Highlight::NORMAL);

		$keywords1 = $this->parent->syntax->keywords1;
		$keywords2 = $this->parent->syntax->keywords2;

		$scs = $this->parent->syntax->singleLineCommentStart;

		$prevSep = TRUE;
		$inString = '';

		$i = 0;

		while ($i < $this->rsize)
		{
			$char = $this->render[$i];
			$prevHl = ($i > 0) ? $this->hl[$i - 1] : Highlight::NORMAL;

			if ($this->parent->syntax === NULL)
			{
				return;
			}

			// Single-line comments
			if ($scs !== '' && empty($inString) && substr($this->render, $i, strlen($scs)) === $scs)// strncmp($char, $scs, strlen($scs)) === 0)
			{
				array_replace_range($this->hl, $i, $this->rsize - $i, Highlight::COMMENT);
				break;
			}

			// String/Char literals
			if ($this->parent->syntax->flags & Syntax::HIGHLIGHT_STRINGS)
			{
				if ($inString !== '')
				{
					$this->hl[$i] = Highlight::STRING;

					// Check for escaped character
					if ($char === '\\' && $i+1 < $this->rsize)
					{
						$this->hl[$i + 1] = Highlight::STRING;
						$i += 2;
						continue;
					}

					if ($char === $inString)
					{
						$inString = '';
					}
					$i++;
					$prevSep = 1;
					continue;
				}

				if ( $char === '""' || $char === '\'')
				{
					$inString = $char;
					$this->hl[$i] = Highlight::STRING;
					$i++;
					continue;
				}
			}

			// Numbers, including decimal points
			if ($this->parent->syntax->flags & Syntax::HIGHLIGHT_NUMBERS)
			{
				if (
					($char === '.' && $prevHl === Highlight::NUMBER) ||
					(($prevSep || $prevHl === Highlight::NUMBER) && is_digit($char))
				)
				{
					$this->hl[$i] = Highlight::NUMBER;
					$i++;
					$prevSep = FALSE;
					continue;
				}
			}

			// Keywords
			if ($prevSep)
			{
				foreach ($keywords1 as $k)
				{
					$klen = strlen($k);
					$nextCharOffset = $i + $klen;
					$isEndOfLine = $nextCharOffset >= $this->rsize;
					$nextChar = ($isEndOfLine) ? "\0" : $this->render[$nextCharOffset];

					if (substr($this->render, $i, $klen) === $k && is_separator($nextChar))
					{
						array_replace_range($this->hl, $i, $klen, Highlight::KEYWORD1);
						$i += $klen - 1;
						break;
					}
				}

				foreach ($keywords2 as $k)
				{
					$klen = strlen($k);
					$nextCharOffset = $i + $klen;
					$isEndOfLine = $nextCharOffset >= $this->rsize;
					$nextChar = ($isEndOfLine) ? "\0" : $this->render[$nextCharOffset];

					if (substr($this->render, $i, $klen) === $k && is_separator($nextChar))
					{
						array_replace_range($this->hl, $i, $klen, Highlight::KEYWORD2);
						$i += $klen - 1;
						break;
					}
				}
			}

			$prevSep = is_separator($char);
			$i++;
		}
	}
}