Cursor::isIndented() - Code Metrics - Inspection of "Cache the current character" - thephpleague/commonmark - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — optimizations ( 75e26b )

by Colin

created 2018-04-11 20:52 UTC

Cursor::isIndented() A

↳ Parent: Cursor

Complexity

Conditions	1
Paths	1

Size

Total Lines	4
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

Metric	Value
dl	0
loc	4
ccs	2
cts	2
cp	1
rs	10
c	0
b	0
f	0
cc	1
eloc	2
nc	1
nop	0
crap	1

<?php

/*
 * This file is part of the league/commonmark package.
 *
 * (c) Colin O'Dell <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace League\CommonMark;

class Cursor
{
    const INDENT_LEVEL = 4;

    /**
     * @var string
     */
    private $line;

    /**
     * @var int
     */
    private $length;

    /**
     * @var int
     *
     * It's possible for this to be 1 char past the end, meaning we've parsed all chars and have
     * reached the end.  In this state, any character-returning method MUST return null.
     */
    private $currentPosition = 0;

    /**
     * @var int
     */
    private $column = 0;

    /**
     * @var int
     */
    private $indent = 0;

    /**
     * @var int
     */
    private $previousPosition = 0;

    /**
     * @var int|null
     */
    private $nextNonSpaceCache;

    /**
     * @var bool
     */
    private $partiallyConsumedTab = false;

    /**
     * @var string
     */
    private $encoding;

    /**
     * @var bool
     */
    private $lineContainsTabs;

    /**
     * @var bool
     */
    private $isMultibyte;

    /**
     * @var int
     */
    private $charCache = [];

    /**
     * @param string $line
     */
    public function __construct($line, $encoding = 'UTF-8')
    {
        $this->line = $line;
        $this->encoding = $encoding;
        $this->length = mb_strlen($line, $this->encoding);
        $this->isMultibyte = $this->length !== strlen($line);
        $this->lineContainsTabs = preg_match('/\t/', $line) > 0;
    }

    /**
     * Returns the position of the next character which is not a space (or tab)
     *
     * @return int
     */
    public function getNextNonSpacePosition()
    {
        if ($this->nextNonSpaceCache !== null) {
            return $this->nextNonSpaceCache;
        }

        $i = $this->currentPosition;
        $cols = $this->column;

        while (($c = $this->getCharacter($i)) !== null) {
            if ($c === ' ') {
                $i++;
                $cols++;
            } elseif ($c === "\t") {
                $i++;
                $cols += (4 - ($cols % 4));
            } else {
                break;
            }
        }

        $nextNonSpace = ($c === null) ? $this->length : $i;
        $this->indent = $cols - $this->column;

        return $this->nextNonSpaceCache = $nextNonSpace;
    }

    /**
     * Returns the next character which isn't a space (or tab)
     *
     * @return string
     */
    public function getNextNonSpaceCharacter()
    {
        return $this->getCharacter($this->getNextNonSpacePosition());
    }

    /**
     * Calculates the current indent (number of spaces after current position)
     *
     * @return int
     */
    public function getIndent()
    {
        if ($this->nextNonSpaceCache === null) {
            $this->getNextNonSpacePosition();
        }

        return $this->indent;
    }

    /**
     * Whether the cursor is indented to INDENT_LEVEL
     *
     * @return bool
     */
    public function isIndented()
    {
        return $this->getIndent() >= self::INDENT_LEVEL;
    }

    /**
     * @param int|null $index
     *
     * @return string|null
     */
    public function getCharacter($index = null)
    {
        if ($index === null) {
            $index = $this->currentPosition;
        }

        if (isset($this->charCache[$index])) {
            return $this->charCache[$index];
        }

        // Index out-of-bounds, or we're at the end
        if ($index < 0 || $index >= $this->length) {
            return;
        }

        return $this->charCache[$index] = mb_substr($this->line, $index, 1, $this->encoding);
    }

    /**
     * Returns the next character (or null, if none) without advancing forwards
     *
     * @param int $offset
     *
     * @return string|null
     */
    public function peek($offset = 1)
    {
        return $this->getCharacter($this->currentPosition + $offset);
    }

    /**
     * Whether the remainder is blank
     *
     * @return bool
     */
    public function isBlank()
    {
        return $this->nextNonSpaceCache === $this->length || $this->getNextNonSpacePosition() === $this->length;
    }

    /**
     * Move the cursor forwards
     */
    public function advance()
    {
        $this->advanceBy(1);
    }

    /**
     * Move the cursor forwards
     *
     * @param int  $characters       Number of characters to advance by
     * @param bool $advanceByColumns Whether to advance by columns instead of spaces
     */
    public function advanceBy($characters, $advanceByColumns = false)
    {
        if ($characters === 0) {
            $this->previousPosition = $this->currentPosition;

            return;
        }

        $this->previousPosition = $this->currentPosition;
        $this->nextNonSpaceCache = null;

        // Optimization to avoid tab handling logic if we have no tabs
        if (!$this->lineContainsTabs || preg_match('/\t/', $nextFewChars = mb_substr($this->line, $this->currentPosition, $characters, $this->encoding)) === 0) {
            $length = min($characters, $this->length - $this->currentPosition);
            $this->partiallyConsumedTab = false;
            $this->currentPosition += $length;
            $this->column += $length;

            return;
        }

        if ($characters === 1 && !empty($nextFewChars)) {
            $asArray = [$nextFewChars];
        } else {
            $asArray = preg_split('//u', $nextFewChars, null, PREG_SPLIT_NO_EMPTY);
        }

        foreach ($asArray as $relPos => $c) {
            if ($c === "\t") {
                $charsToTab = 4 - ($this->column % 4);
                if ($advanceByColumns) {
                    $this->partiallyConsumedTab = $charsToTab > $characters;
                    $charsToAdvance = $charsToTab > $characters ? $characters : $charsToTab;
                    $this->column += $charsToAdvance;
                    $this->currentPosition += $this->partiallyConsumedTab ? 0 : 1;
                    $characters -= $charsToAdvance;
                } else {
                    $this->partiallyConsumedTab = false;
                    $this->column += $charsToTab;
                    $this->currentPosition++;
                    $characters--;
                }
            } else {
                $this->partiallyConsumedTab = false;
                $this->currentPosition++;
                $this->column++;
                $characters--;
            }

            if ($characters <= 0) {
                break;
            }
        }
    }

    /**
     * Advances the cursor by a single space or tab, if present
     *
     * @return bool
     */
    public function advanceBySpaceOrTab()
    {
        $character = $this->getCharacter();

        if ($character === ' ' || $character === "\t") {
            $this->advanceBy(1, true);

            return true;
        }

        return false;
    }

    /**
     * Parse zero or more space/tab characters
     *
     * @return int Number of positions moved
     */
    public function advanceToNextNonSpaceOrTab()
    {
        $newPosition = $this->getNextNonSpacePosition();
        $this->advanceBy($newPosition - $this->currentPosition);
        $this->partiallyConsumedTab = false;

        return $this->currentPosition - $this->previousPosition;
    }

    /**
     * Parse zero or more space characters, including at most one newline.
     *
     * Tab characters are not parsed with this function.
     *
     * @return int Number of positions moved
     */
    public function advanceToNextNonSpaceOrNewline()
    {
        $matches = [];
        preg_match('/^ *(?:\n *)?/', $this->getRemainder(), $matches, PREG_OFFSET_CAPTURE);

        // [0][0] contains the matched text
        // [0][1] contains the index of that match
        $increment = $matches[0][1] + strlen($matches[0][0]);

        if ($increment === 0) {
            return 0;
        }

        $this->advanceBy($increment);

        return $this->currentPosition - $this->previousPosition;
    }

    /**
     * Move the position to the very end of the line
     *
     * @return int The number of characters moved
     */
    public function advanceToEnd()
    {
        $this->previousPosition = $this->currentPosition;
        $this->nextNonSpaceCache = null;

        $this->currentPosition = $this->length;

        return $this->currentPosition - $this->previousPosition;
    }

    /**
     * @return string
     */
    public function getRemainder()
    {
        if ($this->currentPosition >= $this->length) {
            return '';
        }

        $prefix = '';
        $position = $this->currentPosition;
        if ($this->partiallyConsumedTab) {
            $position++;
            $charsToTab = 4 - ($this->column % 4);
            $prefix = str_repeat(' ', $charsToTab);
        }

        return $prefix . mb_substr($this->line, $position, null, $this->encoding);
    }

    /**
     * @return string
     */
    public function getLine()
    {
        return $this->line;
    }

    /**
     * @return bool
     */
    public function isAtEnd()
    {
        return $this->currentPosition >= $this->length;
    }

    /**
     * Try to match a regular expression
     *
     * Returns the matching text and advances to the end of that match
     *
     * @param string $regex
     *
     * @return string|null
     */
    public function match($regex)
    {
        $subject = $this->getRemainder();

        if (!preg_match($regex, $subject, $matches, PREG_OFFSET_CAPTURE)) {
            return;
        }

        // $matches[0][0] contains the matched text
        // $matches[0][1] contains the index of that match

        if ($this->isMultibyte) {
            // PREG_OFFSET_CAPTURE always returns the byte offset, not the char offset, which is annoying
            $offset = mb_strlen(mb_strcut($subject, 0, $matches[0][1], $this->encoding), $this->encoding);
            $matchLength = mb_strlen($matches[0][0], $this->encoding);
        } else {
            $offset = $matches[0][1];
            $matchLength = strlen($matches[0][0]);
        }

        // [0][0] contains the matched text
        // [0][1] contains the index of that match
        $this->advanceBy($offset + $matchLength);

        return $matches[0][0];
    }

    /**
     * Encapsulates the current state of this cursor in case you need to rollback later.
     *
     * WARNING: Do not parse or use the return value for ANYTHING except for
     * passing it back into restoreState(), as the number of values and their
     * contents may change in any future release without warning.
     *
     * @return array
     */
    public function saveState()
    {
        return [
            $this->currentPosition,
            $this->previousPosition,
            $this->nextNonSpaceCache,
            $this->indent,
            $this->column,
            $this->partiallyConsumedTab,
        ];
    }

    /**
     * Restore the cursor to a previous state.
     *
     * Pass in the value previously obtained by calling saveState().
     *
     * @param array $state
     */
    public function restoreState($state)
    {
        list(
            $this->currentPosition,
            $this->previousPosition,
            $this->nextNonSpaceCache,
            $this->indent,
            $this->column,
            $this->partiallyConsumedTab,
          ) = $state;
    }

    /**
     * @return int
     */
    public function getPosition()
    {
        return $this->currentPosition;
    }

    /**
     * @return string
     */
    public function getPreviousText()
    {
        return mb_substr($this->line, $this->previousPosition, $this->currentPosition - $this->previousPosition, $this->encoding);
    }

    /**
     * @return int
     */
    public function getColumn()
    {
        return $this->column;
    }
}


1		<?php
2
3		/*
4		* This file is part of the league/commonmark package.
5		*
6		* (c) Colin O'Dell <[email protected]>
7		*
8		* For the full copyright and license information, please view the LICENSE
9		* file that was distributed with this source code.
10		*/
11
12		namespace League\CommonMark;
13
14		class Cursor
15		{
16		const INDENT_LEVEL = 4;
17
18		/**
19		* @var string
20		*/
21		private $line;
22
23		/**
24		* @var int
25		*/
26		private $length;
27
28		/**
29		* @var int
30		*
31		* It's possible for this to be 1 char past the end, meaning we've parsed all chars and have
32		* reached the end. In this state, any character-returning method MUST return null.
33		*/
34		private $currentPosition = 0;
35
36		/**
37		* @var int
38		*/
39		private $column = 0;
40
41		/**
42		* @var int
43		*/
44		private $indent = 0;
45
46		/**
47		* @var int
48		*/
49		private $previousPosition = 0;
50
51		/**
52		* @var int\|null
53		*/
54		private $nextNonSpaceCache;
55
56		/**
57		* @var bool
58		*/
59		private $partiallyConsumedTab = false;
60
61		/**
62		* @var string
63		*/
64		private $encoding;
65
66		/**
67		* @var bool
68		*/
69		private $lineContainsTabs;
70
71		/**
72		* @var bool
73		*/
74		private $isMultibyte;
75
76		/**
77		* @var int
78		*/
79		private $charCache = [];
80
81		/**
82		* @param string $line
83		*/
84	2391	public function __construct($line, $encoding = 'UTF-8')
85		{
86	2391	$this->line = $line;
87	2391	$this->encoding = $encoding;
88	2391	$this->length = mb_strlen($line, $this->encoding);
89	2391	$this->isMultibyte = $this->length !== strlen($line);
90	2391	$this->lineContainsTabs = preg_match('/\t/', $line) > 0;
91	2391	}
92
93		/**
94		* Returns the position of the next character which is not a space (or tab)
95		*
96		* @return int
97		*/
98	2118	public function getNextNonSpacePosition()
99		{
100	2118	if ($this->nextNonSpaceCache !== null) {
101	1938	return $this->nextNonSpaceCache;
102		}
103
104	2118	$i = $this->currentPosition;
105	2118	$cols = $this->column;
106
107	2118	while (($c = $this->getCharacter($i)) !== null) {
108	2094	if ($c === ' ') {
109	504	$i++;
110	504	$cols++;
111	2066	} elseif ($c === "\t") {
112	36	$i++;
113	36	$cols += (4 - ($cols % 4));
114	12	} else {
115	2052	break;
116		}
117	175	}
118
119	2118	$nextNonSpace = ($c === null) ? $this->length : $i;
120	2118	$this->indent = $cols - $this->column;
121
122	2118	return $this->nextNonSpaceCache = $nextNonSpace;
123		}
124
125		/**
126		* Returns the next character which isn't a space (or tab)
127		*
128		* @return string
129		*/
130	1911	public function getNextNonSpaceCharacter()
131		{
132	1911	return $this->getCharacter($this->getNextNonSpacePosition());
133		}
134
135		/**
136		* Calculates the current indent (number of spaces after current position)
137		*
138		* @return int
139		*/
140	1998	public function getIndent()
141		{
142	1998	if ($this->nextNonSpaceCache === null) {
143	1998	$this->getNextNonSpacePosition();
144	666	}
145
146	1998	return $this->indent;
147		}
148
149		/**
150		* Whether the cursor is indented to INDENT_LEVEL
151		*
152		* @return bool
153		*/
154	1938	public function isIndented()
155		{
156	1938	return $this->getIndent() >= self::INDENT_LEVEL;
157		}
158
159		/**
160		* @param int\|null $index
161		*
162		* @return string\|null
163		*/
164	2172	public function getCharacter($index = null)
165		{
166	2172	if ($index === null) {
167	1689	$index = $this->currentPosition;
168	563	}
169
170	2172	if (isset($this->charCache[$index])) {
171	1956	return $this->charCache[$index];
172		}
173
174		// Index out-of-bounds, or we're at the end
175	2172	if ($index < 0 \|\| $index >= $this->length) {
176	1893	return;
177		}
178
179	2130	return $this->charCache[$index] = mb_substr($this->line, $index, 1, $this->encoding);
180		}
181
182		/**
183		* Returns the next character (or null, if none) without advancing forwards
184		*
185		* @param int $offset
186		*
187		* @return string\|null
188		*/
189	1020	public function peek($offset = 1)
190		{
191	1020	return $this->getCharacter($this->currentPosition + $offset);
192		}
193
194		/**
195		* Whether the remainder is blank
196		*
197		* @return bool
198		*/
199	1956	public function isBlank()
200		{
201	1956	return $this->nextNonSpaceCache === $this->length \|\| $this->getNextNonSpacePosition() === $this->length;
202		}
203
204		/**
205		* Move the cursor forwards
206		*/
207	795	public function advance()
208		{
209	795	$this->advanceBy(1);
210	795	}
211
212		/**
213		* Move the cursor forwards
214		*
215		* @param int $characters Number of characters to advance by
216		* @param bool $advanceByColumns Whether to advance by columns instead of spaces
217		*/
218	2247	public function advanceBy($characters, $advanceByColumns = false)
219		{
220	2247	if ($characters === 0) {
221	1968	$this->previousPosition = $this->currentPosition;
222
223	1968	return;
224		}
225
226	2106	$this->previousPosition = $this->currentPosition;
227	2106	$this->nextNonSpaceCache = null;
228
229		// Optimization to avoid tab handling logic if we have no tabs
230	2106	if (!$this->lineContainsTabs \|\| preg_match('/\t/', $nextFewChars = mb_substr($this->line, $this->currentPosition, $characters, $this->encoding)) === 0) {
231	2094	$length = min($characters, $this->length - $this->currentPosition);
232	2094	$this->partiallyConsumedTab = false;
233	2094	$this->currentPosition += $length;
234	2094	$this->column += $length;
235
236	2094	return;
237		}
238
239	45	if ($characters === 1 && !empty($nextFewChars)) {
240	18	$asArray = [$nextFewChars];
241	6	} else {
242	39	$asArray = preg_split('//u', $nextFewChars, null, PREG_SPLIT_NO_EMPTY);
243		}
244
245	45	foreach ($asArray as $relPos => $c) {
246	45	if ($c === "\t") {
247	45	$charsToTab = 4 - ($this->column % 4);
248	45	if ($advanceByColumns) {
249	33	$this->partiallyConsumedTab = $charsToTab > $characters;
250	33	$charsToAdvance = $charsToTab > $characters ? $characters : $charsToTab;
251	33	$this->column += $charsToAdvance;
252	33	$this->currentPosition += $this->partiallyConsumedTab ? 0 : 1;
253	33	$characters -= $charsToAdvance;
254	11	} else {
255	18	$this->partiallyConsumedTab = false;
256	18	$this->column += $charsToTab;
257	18	$this->currentPosition++;
258	36	$characters--;
259		}
260	15	} else {
261	12	$this->partiallyConsumedTab = false;
262	12	$this->currentPosition++;
263	12	$this->column++;
264	12	$characters--;
265		}
266
267	45	if ($characters <= 0) {
268	45	break;
269		}
270	15	}
271	45	}
272
273		/**
274		* Advances the cursor by a single space or tab, if present
275		*
276		* @return bool
277		*/
278	339	public function advanceBySpaceOrTab()
279		{
280	339	$character = $this->getCharacter();
281
282	339	if ($character === ' ' \|\| $character === "\t") {
283	327	$this->advanceBy(1, true);
284
285	327	return true;
286		}
287
288	249	return false;
289		}
290
291		/**
292		* Parse zero or more space/tab characters
293		*
294		* @return int Number of positions moved
295		*/
296	1848	public function advanceToNextNonSpaceOrTab()
297		{
298	1848	$newPosition = $this->getNextNonSpacePosition();
299	1848	$this->advanceBy($newPosition - $this->currentPosition);
300	1848	$this->partiallyConsumedTab = false;
301
302	1848	return $this->currentPosition - $this->previousPosition;
303		}
304
305		/**
306		* Parse zero or more space characters, including at most one newline.
307		*
308		* Tab characters are not parsed with this function.
309		*
310		* @return int Number of positions moved
311		*/
312	441	public function advanceToNextNonSpaceOrNewline()
313		{
314	441	$matches = [];
315	441	preg_match('/^ (?:\n )?/', $this->getRemainder(), $matches, PREG_OFFSET_CAPTURE);
316
317		// [0][0] contains the matched text
318		// [0][1] contains the index of that match
319	441	$increment = $matches[0][1] + strlen($matches[0][0]);
320
321	441	if ($increment === 0) {
322	300	return 0;
323		}
324
325	300	$this->advanceBy($increment);
326
327	300	return $this->currentPosition - $this->previousPosition;
328		}
329
330		/**
331		* Move the position to the very end of the line
332		*
333		* @return int The number of characters moved
334		*/
335	84	public function advanceToEnd()
336		{
337	84	$this->previousPosition = $this->currentPosition;
338	84	$this->nextNonSpaceCache = null;
339
340	84	$this->currentPosition = $this->length;
341
342	84	return $this->currentPosition - $this->previousPosition;
343		}
344
345		/**
346		* @return string
347		*/
348	2043	public function getRemainder()
349		{
350	2043	if ($this->currentPosition >= $this->length) {
351	693	return '';
352		}
353
354	2028	$prefix = '';
355	2028	$position = $this->currentPosition;
356	2028	if ($this->partiallyConsumedTab) {
357	15	$position++;
358	15	$charsToTab = 4 - ($this->column % 4);
359	15	$prefix = str_repeat(' ', $charsToTab);
360	5	}
361
362	2028	return $prefix . mb_substr($this->line, $position, null, $this->encoding);
363		}
364
365		/**
366		* @return string
367		*/
368	1887	public function getLine()
369		{
370	1887	return $this->line;
371		}
372
373		/**
374		* @return bool
375		*/
376	411	public function isAtEnd()
377		{
378	411	return $this->currentPosition >= $this->length;
379		}
380
381		/**
382		* Try to match a regular expression
383		*
384		* Returns the matching text and advances to the end of that match
385		*
386		* @param string $regex
387		*
388		* @return string\|null
389		*/
390	1908	public function match($regex)
391		{
392	1908	$subject = $this->getRemainder();
393
394	1908	if (!preg_match($regex, $subject, $matches, PREG_OFFSET_CAPTURE)) {
395	1758	return;
396		}
397
398		// $matches[0][0] contains the matched text
399		// $matches[0][1] contains the index of that match
400
401	1782	if ($this->isMultibyte) {
402		// PREG_OFFSET_CAPTURE always returns the byte offset, not the char offset, which is annoying
403	51	$offset = mb_strlen(mb_strcut($subject, 0, $matches[0][1], $this->encoding), $this->encoding);
404	51	$matchLength = mb_strlen($matches[0][0], $this->encoding);
405	17	} else {
406	1731	$offset = $matches[0][1];
407	1731	$matchLength = strlen($matches[0][0]);
408		}
409
410		// [0][0] contains the matched text
411		// [0][1] contains the index of that match
412	1782	$this->advanceBy($offset + $matchLength);
413
414	1782	return $matches[0][0];
415		}
416
417		/**
418		* Encapsulates the current state of this cursor in case you need to rollback later.
419		*
420		* WARNING: Do not parse or use the return value for ANYTHING except for
421		* passing it back into restoreState(), as the number of values and their
422		* contents may change in any future release without warning.
423		*
424		* @return array
425		*/
426	1011	public function saveState()
427		{
428		return [
429	1011	$this->currentPosition,
430	1011	$this->previousPosition,
431	1011	$this->nextNonSpaceCache,
432	1011	$this->indent,
433	1011	$this->column,
434	1011	$this->partiallyConsumedTab,
435	337	];
436		}
437
438		/**
439		* Restore the cursor to a previous state.
440		*
441		* Pass in the value previously obtained by calling saveState().
442		*
443		* @param array $state
444		*/
445	795	public function restoreState($state)
446		{
447		list(
448	795	$this->currentPosition,
449	795	$this->previousPosition,
450	795	$this->nextNonSpaceCache,
451	795	$this->indent,
452	795	$this->column,
453	795	$this->partiallyConsumedTab,
454	795	) = $state;
455	795	}
456
457		/**
458		* @return int
459		*/
460	648	public function getPosition()
461		{
462	648	return $this->currentPosition;
463		}
464
465		/**
466		* @return string
467		*/
468	870	public function getPreviousText()
469		{
470	870	return mb_substr($this->line, $this->previousPosition, $this->currentPosition - $this->previousPosition, $this->encoding);
471		}
472
473		/**
474		* @return int
475		*/
476	240	public function getColumn()
477		{
478	240	return $this->column;
479		}
480		}
481

thephpleague / commonmark

Push — optimizations ( 75e26b )

Cursor::isIndented() A

Complexity

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Duplication

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