ctucx.git: ctucx.things

simple inventory management web-app

1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
57 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
88 
89 
90 
91 
92 
93 
94 
95 
96 
97 
98 
99 
100 
101 
102 
103 
104 
105 
106 
107 
108 
109 
110 
111 
112 
113 
114 
115 
116 
117 
118 
119 
120 
121 
122 
123 
124 
125 
126 
127 
128 
129 
130 
131 
132 
133 
134 
135 
136 
137 
138 
139 
140 
141 
142 
143 
144 
145 
146 
147 
148 
149 
150 
151 
152 
153 
154 
155 
156 
157 
158 
159 
160 
161 
162 
163 
164 
165 
166 
167 
168 
169 
170 
171 
172 
173 
174 
175 
176 
177 
178 
179 
180 
181 
182 
183 
184 
185 
186 
187 
188 
189 
190 
191 
192 
193 
194 
195 
196 
197 
198 
199 
200 
201 
202 
203 
204 
205 
206 
207 
208 
209 
210 
211 
212 
213 
214 
215 
216 
217 
218 
219 
220 
221 
222 
223 
224 
225 
226 
227 
228 
229 
230 
231 
232 
233 
234 
235 
236 
237 
238 
239 
240 
241 
242 
243 
244 
245 
246 
247 
248 
249 
250 
251 
252 
253 
254 
255 
256 
257 
258 
259 
260 
261 
262 
263 
264 
265 
266 
267 
268 
269 
270 
271 
272 
273 
274 
275 
276 
277 
278 
279 
280 
281 
282 
283 
284 
285 
286 
287 
288 
289 
290 
291 
292 
293 
294 
295 
296 
297 
298 
299 
300 
301 
302 
303 
304 
305 
306 
307 
308 
309 
310 
311 
312 
313 
314 
315 
316 
317 
318 
319 
320 
321 
322 
323 
324 
325 
326 
327 
328 
329 
330 
331 
332 
333 
334 
335 
336 
337 
338 
339 
340 
341 
342 
343 
344 
345 
346 
347 
348 
349 
350 
351 
352 
353 
354 
355 
356 
357 
358 
359 
360 
361 
362 
363 
364 
365 
366 
367 
368 
369 
370 
371 
372 
373 
374 
375 
376 
377 
378 
379 
380 
381 
382 
383 
384 
385 
386 
387 
388 
389 
390 
391 
392 
393 
394 
395 
396 
397 
398 
399 
400 
401 
402 
403 
404 
405 
406 
407 
408 
409 
410 
411 
412 
413 
414 
415 
416 
417 
418 
419 
420 
421 
422 
423 
424 
425 
426 
427 
428 
429 
430 
431 
432 
433 
434 
435 
436 
437 
438 
439 
440 
441 
442 
443 
444 
445 
446 
447 
448 
449 
450 
451 
452 
453 
454 
455 
456 
457 
458 
459 
460 
461 
462 
463 
464 
465 
466 
467 
468 
469 
470 
471 
472 
473 
474 
475 
476 
477 
478 
479 
480 
481 
482 
483 
484 
485 
486 
487 
488 
489 
490 
491 
492 
493 
494 
495 
496 
497 
498 
499 
500 
501 
502 
503 
504 
505 
506 
507 
508 
509 
510 
511 
512 
513 
514 
515 
516 
517 
518 
519 
520 
521 
522 
523 
524 
525 
526 
527 
528 
529 
530 
531 
532 
533 
534 
535 
536 
537 
538 
539 
540 
541 
542 
543 
544 
545 
546 
547 
548 
549 
550 
551 
552 
553 
554 
555 
556 
557 
558 
559 
560 
561 
562 
563 
564 
565 
566 
567 
568 
569 
570 
571 
572 
573 
574 
575 
576 
577 
578 
579 
580 
581 
582 
583 
584 
585 
586 
587 
588 
589 
590 
591 
592 
593 
594 
595 
596 
597 
598 
599 
600 
601 
602 
603 
604 
605 
606 
607 
608 
609 
610 
611 
612 
613 
614 
615 
616 
617 
618 
619 
620 
621 
622 
623 
624 
625 
626 
627 
628 
629 
630 
631 
632 
633 
634 
635 
636 
637 
638 
639 
640 
641 
642 
643 
644 
645 
646 
647 
648 
649 
650 
651 
652 
653 
654 
655 
656 
657 
658 
659 
660 
661 
662 
663 
664 
665 
666 
667 
668 
669 
670 
671 
672 
673 
674 
675 
676 
677 
678 
679 
680 
681 
682 
683 
684 
685 
686 
687 
688 
689 
<?php

/*
 * This file is part of Mustache.php.
 *
 * (c) 2010-2017 Justin Hileman
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Mustache Compiler class.
 *
 * This class is responsible for turning a Mustache token parse tree into normal PHP source code.
 */
class Mustache_Compiler
{
    private $pragmas;
    private $defaultPragmas = array();
    private $sections;
    private $blocks;
    private $source;
    private $indentNextLine;
    private $customEscape;
    private $entityFlags;
    private $charset;
    private $strictCallables;

    /**
     * Compile a Mustache token parse tree into PHP source code.
     *
     * @param string $source          Mustache Template source code
     * @param string $tree            Parse tree of Mustache tokens
     * @param string $name            Mustache Template class name
     * @param bool   $customEscape    (default: false)
     * @param string $charset         (default: 'UTF-8')
     * @param bool   $strictCallables (default: false)
     * @param int    $entityFlags     (default: ENT_COMPAT)
     *
     * @return string Generated PHP source code
     */
    public function compile($source, array $tree, $name, $customEscape = false, $charset = 'UTF-8', $strictCallables = false, $entityFlags = ENT_COMPAT)
    {
        $this->pragmas         = $this->defaultPragmas;
        $this->sections        = array();
        $this->blocks          = array();
        $this->source          = $source;
        $this->indentNextLine  = true;
        $this->customEscape    = $customEscape;
        $this->entityFlags     = $entityFlags;
        $this->charset         = $charset;
        $this->strictCallables = $strictCallables;

        return $this->writeCode($tree, $name);
    }

    /**
     * Enable pragmas across all templates, regardless of the presence of pragma
     * tags in the individual templates.
     *
     * @internal Users should set global pragmas in Mustache_Engine, not here :)
     *
     * @param string[] $pragmas
     */
    public function setPragmas(array $pragmas)
    {
        $this->pragmas = array();
        foreach ($pragmas as $pragma) {
            $this->pragmas[$pragma] = true;
        }
        $this->defaultPragmas = $this->pragmas;
    }

    /**
     * Helper function for walking the Mustache token parse tree.
     *
     * @throws Mustache_Exception_SyntaxException upon encountering unknown token types
     *
     * @param array $tree  Parse tree of Mustache tokens
     * @param int   $level (default: 0)
     *
     * @return string Generated PHP source code
     */
    private function walk(array $tree, $level = 0)
    {
        $code = '';
        $level++;
        foreach ($tree as $node) {
            switch ($node[Mustache_Tokenizer::TYPE]) {
                case Mustache_Tokenizer::T_PRAGMA:
                    $this->pragmas[$node[Mustache_Tokenizer::NAME]] = true;
                    break;

                case Mustache_Tokenizer::T_SECTION:
                    $code .= $this->section(
                        $node[Mustache_Tokenizer::NODES],
                        $node[Mustache_Tokenizer::NAME],
                        isset($node[Mustache_Tokenizer::FILTERS]) ? $node[Mustache_Tokenizer::FILTERS] : array(),
                        $node[Mustache_Tokenizer::INDEX],
                        $node[Mustache_Tokenizer::END],
                        $node[Mustache_Tokenizer::OTAG],
                        $node[Mustache_Tokenizer::CTAG],
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_INVERTED:
                    $code .= $this->invertedSection(
                        $node[Mustache_Tokenizer::NODES],
                        $node[Mustache_Tokenizer::NAME],
                        isset($node[Mustache_Tokenizer::FILTERS]) ? $node[Mustache_Tokenizer::FILTERS] : array(),
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_PARTIAL:
                    $code .= $this->partial(
                        $node[Mustache_Tokenizer::NAME],
                        isset($node[Mustache_Tokenizer::INDENT]) ? $node[Mustache_Tokenizer::INDENT] : '',
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_PARENT:
                    $code .= $this->parent(
                        $node[Mustache_Tokenizer::NAME],
                        isset($node[Mustache_Tokenizer::INDENT]) ? $node[Mustache_Tokenizer::INDENT] : '',
                        $node[Mustache_Tokenizer::NODES],
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_BLOCK_ARG:
                    $code .= $this->blockArg(
                        $node[Mustache_Tokenizer::NODES],
                        $node[Mustache_Tokenizer::NAME],
                        $node[Mustache_Tokenizer::INDEX],
                        $node[Mustache_Tokenizer::END],
                        $node[Mustache_Tokenizer::OTAG],
                        $node[Mustache_Tokenizer::CTAG],
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_BLOCK_VAR:
                    $code .= $this->blockVar(
                        $node[Mustache_Tokenizer::NODES],
                        $node[Mustache_Tokenizer::NAME],
                        $node[Mustache_Tokenizer::INDEX],
                        $node[Mustache_Tokenizer::END],
                        $node[Mustache_Tokenizer::OTAG],
                        $node[Mustache_Tokenizer::CTAG],
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_COMMENT:
                    break;

                case Mustache_Tokenizer::T_ESCAPED:
                case Mustache_Tokenizer::T_UNESCAPED:
                case Mustache_Tokenizer::T_UNESCAPED_2:
                    $code .= $this->variable(
                        $node[Mustache_Tokenizer::NAME],
                        isset($node[Mustache_Tokenizer::FILTERS]) ? $node[Mustache_Tokenizer::FILTERS] : array(),
                        $node[Mustache_Tokenizer::TYPE] === Mustache_Tokenizer::T_ESCAPED,
                        $level
                    );
                    break;

                case Mustache_Tokenizer::T_TEXT:
                    $code .= $this->text($node[Mustache_Tokenizer::VALUE], $level);
                    break;

                default:
                    throw new Mustache_Exception_SyntaxException(sprintf('Unknown token type: %s', $node[Mustache_Tokenizer::TYPE]), $node);
            }
        }

        return $code;
    }

    const KLASS = '<?php

        class %s extends Mustache_Template
        {
            private $lambdaHelper;%s

            public function renderInternal(Mustache_Context $context, $indent = \'\')
            {
                $this->lambdaHelper = new Mustache_LambdaHelper($this->mustache, $context);
                $buffer = \'\';
        %s

                return $buffer;
            }
        %s
        %s
        }';

    const KLASS_NO_LAMBDAS = '<?php

        class %s extends Mustache_Template
        {%s
            public function renderInternal(Mustache_Context $context, $indent = \'\')
            {
                $buffer = \'\';
        %s

                return $buffer;
            }
        }';

    const STRICT_CALLABLE = 'protected $strictCallables = true;';

    /**
     * Generate Mustache Template class PHP source.
     *
     * @param array  $tree Parse tree of Mustache tokens
     * @param string $name Mustache Template class name
     *
     * @return string Generated PHP source code
     */
    private function writeCode($tree, $name)
    {
        $code     = $this->walk($tree);
        $sections = implode("\n", $this->sections);
        $blocks   = implode("\n", $this->blocks);
        $klass    = empty($this->sections) && empty($this->blocks) ? self::KLASS_NO_LAMBDAS : self::KLASS;

        $callable = $this->strictCallables ? $this->prepare(self::STRICT_CALLABLE) : '';

        return sprintf($this->prepare($klass, 0, false, true), $name, $callable, $code, $sections, $blocks);
    }

    const BLOCK_VAR = '
        $blockFunction = $context->findInBlock(%s);
        if (is_callable($blockFunction)) {
            $buffer .= call_user_func($blockFunction, $context);
        %s}
    ';

    const BLOCK_VAR_ELSE = '} else {%s';

    /**
     * Generate Mustache Template inheritance block variable PHP source.
     *
     * @param array  $nodes Array of child tokens
     * @param string $id    Section name
     * @param int    $start Section start offset
     * @param int    $end   Section end offset
     * @param string $otag  Current Mustache opening tag
     * @param string $ctag  Current Mustache closing tag
     * @param int    $level
     *
     * @return string Generated PHP source code
     */
    private function blockVar($nodes, $id, $start, $end, $otag, $ctag, $level)
    {
        $id = var_export($id, true);

        $else = $this->walk($nodes, $level);
        if ($else !== '') {
            $else = sprintf($this->prepare(self::BLOCK_VAR_ELSE, $level + 1, false, true), $else);
        }

        return sprintf($this->prepare(self::BLOCK_VAR, $level), $id, $else);
    }

    const BLOCK_ARG = '%s => array($this, \'block%s\'),';

    /**
     * Generate Mustache Template inheritance block argument PHP source.
     *
     * @param array  $nodes Array of child tokens
     * @param string $id    Section name
     * @param int    $start Section start offset
     * @param int    $end   Section end offset
     * @param string $otag  Current Mustache opening tag
     * @param string $ctag  Current Mustache closing tag
     * @param int    $level
     *
     * @return string Generated PHP source code
     */
    private function blockArg($nodes, $id, $start, $end, $otag, $ctag, $level)
    {
        $key = $this->block($nodes);
        $id = var_export($id, true);

        return sprintf($this->prepare(self::BLOCK_ARG, $level), $id, $key);
    }

    const BLOCK_FUNCTION = '
        public function block%s($context)
        {
            $indent = $buffer = \'\';%s

            return $buffer;
        }
    ';

    /**
     * Generate Mustache Template inheritance block function PHP source.
     *
     * @param array $nodes Array of child tokens
     *
     * @return string key of new block function
     */
    private function block($nodes)
    {
        $code = $this->walk($nodes, 0);
        $key = ucfirst(md5($code));

        if (!isset($this->blocks[$key])) {
            $this->blocks[$key] = sprintf($this->prepare(self::BLOCK_FUNCTION, 0), $key, $code);
        }

        return $key;
    }

    const SECTION_CALL = '
        $value = $context->%s(%s);%s
        $buffer .= $this->section%s($context, $indent, $value);
    ';

    const SECTION = '
        private function section%s(Mustache_Context $context, $indent, $value)
        {
            $buffer = \'\';

            if (%s) {
                $source = %s;
                $result = (string) call_user_func($value, $source, %s);
                if (strpos($result, \'{{\') === false) {
                    $buffer .= $result;
                } else {
                    $buffer .= $this->mustache
                        ->loadLambda($result%s)
                        ->renderInternal($context);
                }
            } elseif (!empty($value)) {
                $values = $this->isIterable($value) ? $value : array($value);
                foreach ($values as $value) {
                    $context->push($value);
                    %s
                    $context->pop();
                }
            }

            return $buffer;
        }
    ';

    /**
     * Generate Mustache Template section PHP source.
     *
     * @param array    $nodes   Array of child tokens
     * @param string   $id      Section name
     * @param string[] $filters Array of filters
     * @param int      $start   Section start offset
     * @param int      $end     Section end offset
     * @param string   $otag    Current Mustache opening tag
     * @param string   $ctag    Current Mustache closing tag
     * @param int      $level
     *
     * @return string Generated section PHP source code
     */
    private function section($nodes, $id, $filters, $start, $end, $otag, $ctag, $level)
    {
        $source   = var_export(substr($this->source, $start, $end - $start), true);
        $callable = $this->getCallable();

        if ($otag !== '{{' || $ctag !== '}}') {
            $delimTag = var_export(sprintf('{{= %s %s =}}', $otag, $ctag), true);
            $helper = sprintf('$this->lambdaHelper->withDelimiters(%s)', $delimTag);
            $delims = ', ' . $delimTag;
        } else {
            $helper = '$this->lambdaHelper';
            $delims = '';
        }

        $key = ucfirst(md5($delims . "\n" . $source));

        if (!isset($this->sections[$key])) {
            $this->sections[$key] = sprintf($this->prepare(self::SECTION), $key, $callable, $source, $helper, $delims, $this->walk($nodes, 2));
        }

        $method  = $this->getFindMethod($id);
        $id      = var_export($id, true);
        $filters = $this->getFilters($filters, $level);

        return sprintf($this->prepare(self::SECTION_CALL, $level), $method, $id, $filters, $key);
    }

    const INVERTED_SECTION = '
        $value = $context->%s(%s);%s
        if (empty($value)) {
            %s
        }
    ';

    /**
     * Generate Mustache Template inverted section PHP source.
     *
     * @param array    $nodes   Array of child tokens
     * @param string   $id      Section name
     * @param string[] $filters Array of filters
     * @param int      $level
     *
     * @return string Generated inverted section PHP source code
     */
    private function invertedSection($nodes, $id, $filters, $level)
    {
        $method  = $this->getFindMethod($id);
        $id      = var_export($id, true);
        $filters = $this->getFilters($filters, $level);

        return sprintf($this->prepare(self::INVERTED_SECTION, $level), $method, $id, $filters, $this->walk($nodes, $level));
    }

    const PARTIAL_INDENT = ', $indent . %s';
    const PARTIAL = '
        if ($partial = $this->mustache->loadPartial(%s)) {
            $buffer .= $partial->renderInternal($context%s);
        }
    ';

    /**
     * Generate Mustache Template partial call PHP source.
     *
     * @param string $id     Partial name
     * @param string $indent Whitespace indent to apply to partial
     * @param int    $level
     *
     * @return string Generated partial call PHP source code
     */
    private function partial($id, $indent, $level)
    {
        if ($indent !== '') {
            $indentParam = sprintf(self::PARTIAL_INDENT, var_export($indent, true));
        } else {
            $indentParam = '';
        }

        return sprintf(
            $this->prepare(self::PARTIAL, $level),
            var_export($id, true),
            $indentParam
        );
    }

    const PARENT = '
        if ($parent = $this->mustache->loadPartial(%s)) {
            $context->pushBlockContext(array(%s
            ));
            $buffer .= $parent->renderInternal($context, $indent);
            $context->popBlockContext();
        }
    ';

    const PARENT_NO_CONTEXT = '
        if ($parent = $this->mustache->loadPartial(%s)) {
            $buffer .= $parent->renderInternal($context, $indent);
        }
    ';

    /**
     * Generate Mustache Template inheritance parent call PHP source.
     *
     * @param string $id       Parent tag name
     * @param string $indent   Whitespace indent to apply to parent
     * @param array  $children Child nodes
     * @param int    $level
     *
     * @return string Generated PHP source code
     */
    private function parent($id, $indent, array $children, $level)
    {
        $realChildren = array_filter($children, array(__CLASS__, 'onlyBlockArgs'));

        if (empty($realChildren)) {
            return sprintf($this->prepare(self::PARENT_NO_CONTEXT, $level), var_export($id, true));
        }

        return sprintf(
            $this->prepare(self::PARENT, $level),
            var_export($id, true),
            $this->walk($realChildren, $level + 1)
        );
    }

    /**
     * Helper method for filtering out non-block-arg tokens.
     *
     * @param array $node
     *
     * @return bool True if $node is a block arg token
     */
    private static function onlyBlockArgs(array $node)
    {
        return $node[Mustache_Tokenizer::TYPE] === Mustache_Tokenizer::T_BLOCK_ARG;
    }

    const VARIABLE = '
        $value = $this->resolveValue($context->%s(%s), $context);%s
        $buffer .= %s($value === null ? \'\' : %s);
    ';

    /**
     * Generate Mustache Template variable interpolation PHP source.
     *
     * @param string   $id      Variable name
     * @param string[] $filters Array of filters
     * @param bool     $escape  Escape the variable value for output?
     * @param int      $level
     *
     * @return string Generated variable interpolation PHP source
     */
    private function variable($id, $filters, $escape, $level)
    {
        $method  = $this->getFindMethod($id);
        $id      = ($method !== 'last') ? var_export($id, true) : '';
        $filters = $this->getFilters($filters, $level);
        $value   = $escape ? $this->getEscape() : '$value';

        return sprintf($this->prepare(self::VARIABLE, $level), $method, $id, $filters, $this->flushIndent(), $value);
    }

    const FILTER = '
        $filter = $context->%s(%s);
        if (!(%s)) {
            throw new Mustache_Exception_UnknownFilterException(%s);
        }
        $value = call_user_func($filter, $value);%s
    ';

    /**
     * Generate Mustache Template variable filtering PHP source.
     *
     * @param string[] $filters Array of filters
     * @param int      $level
     *
     * @return string Generated filter PHP source
     */
    private function getFilters(array $filters, $level)
    {
        if (empty($filters)) {
            return '';
        }

        $name     = array_shift($filters);
        $method   = $this->getFindMethod($name);
        $filter   = ($method !== 'last') ? var_export($name, true) : '';
        $callable = $this->getCallable('$filter');
        $msg      = var_export($name, true);

        return sprintf($this->prepare(self::FILTER, $level), $method, $filter, $callable, $msg, $this->getFilters($filters, $level));
    }

    const LINE = '$buffer .= "\n";';
    const TEXT = '$buffer .= %s%s;';

    /**
     * Generate Mustache Template output Buffer call PHP source.
     *
     * @param string $text
     * @param int    $level
     *
     * @return string Generated output Buffer call PHP source
     */
    private function text($text, $level)
    {
        $indentNextLine = (substr($text, -1) === "\n");
        $code = sprintf($this->prepare(self::TEXT, $level), $this->flushIndent(), var_export($text, true));
        $this->indentNextLine = $indentNextLine;

        return $code;
    }

    /**
     * Prepare PHP source code snippet for output.
     *
     * @param string $text
     * @param int    $bonus          Additional indent level (default: 0)
     * @param bool   $prependNewline Prepend a newline to the snippet? (default: true)
     * @param bool   $appendNewline  Append a newline to the snippet? (default: false)
     *
     * @return string PHP source code snippet
     */
    private function prepare($text, $bonus = 0, $prependNewline = true, $appendNewline = false)
    {
        $text = ($prependNewline ? "\n" : '') . trim($text);
        if ($prependNewline) {
            $bonus++;
        }
        if ($appendNewline) {
            $text .= "\n";
        }

        return preg_replace("/\n( {8})?/", "\n" . str_repeat(' ', $bonus * 4), $text);
    }

    const DEFAULT_ESCAPE = 'htmlspecialchars(%s, %s, %s)';
    const CUSTOM_ESCAPE  = 'call_user_func($this->mustache->getEscape(), %s)';

    /**
     * Get the current escaper.
     *
     * @param string $value (default: '$value')
     *
     * @return string Either a custom callback, or an inline call to `htmlspecialchars`
     */
    private function getEscape($value = '$value')
    {
        if ($this->customEscape) {
            return sprintf(self::CUSTOM_ESCAPE, $value);
        }

        return sprintf(self::DEFAULT_ESCAPE, $value, var_export($this->entityFlags, true), var_export($this->charset, true));
    }

    /**
     * Select the appropriate Context `find` method for a given $id.
     *
     * The return value will be one of `find`, `findDot`, `findAnchoredDot` or `last`.
     *
     * @see Mustache_Context::find
     * @see Mustache_Context::findDot
     * @see Mustache_Context::last
     *
     * @param string $id Variable name
     *
     * @return string `find` method name
     */
    private function getFindMethod($id)
    {
        if ($id === '.') {
            return 'last';
        }

        if (isset($this->pragmas[Mustache_Engine::PRAGMA_ANCHORED_DOT]) && $this->pragmas[Mustache_Engine::PRAGMA_ANCHORED_DOT]) {
            if (substr($id, 0, 1) === '.') {
                return 'findAnchoredDot';
            }
        }

        if (strpos($id, '.') === false) {
            return 'find';
        }

        return 'findDot';
    }

    const IS_CALLABLE        = '!is_string(%s) && is_callable(%s)';
    const STRICT_IS_CALLABLE = 'is_object(%s) && is_callable(%s)';

    /**
     * Helper function to compile strict vs lax "is callable" logic.
     *
     * @param string $variable (default: '$value')
     *
     * @return string "is callable" logic
     */
    private function getCallable($variable = '$value')
    {
        $tpl = $this->strictCallables ? self::STRICT_IS_CALLABLE : self::IS_CALLABLE;

        return sprintf($tpl, $variable, $variable);
    }

    const LINE_INDENT = '$indent . ';

    /**
     * Get the current $indent prefix to write to the buffer.
     *
     * @return string "$indent . " or ""
     */
    private function flushIndent()
    {
        if (!$this->indentNextLine) {
            return '';
        }

        $this->indentNextLine = false;

        return self::LINE_INDENT;
    }
}