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<?php |
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namespace Sphpeme; |
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class Reader |
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{ |
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private $tokenizeRegexp = '/\s*(,@|[(\'`,)]|"(?:[\\].|[^\\"])*"|;.*|[^\s(\'"`,;)]*)(.*)/'; |
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private $file; |
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private $line = ''; |
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private $quotes; |
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public function __construct($file) |
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{ |
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if (!\is_resource($file) || get_resource_type($file) !== 'stream') { |
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throw new \InvalidArgumentException('Must give me a file stream'); |
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} |
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$this->quotes = [ |
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'\'' => Symbol::make('quote'), |
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'``' => Symbol::make('quasiquote'), |
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',' => Symbol::make('unquote'), |
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',@' => Symbol::make('unquote-splicing'), |
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]; |
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$this->file = $file; |
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} |
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/** |
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* @param $token |
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* @return array|mixed |
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* @throws \Exception |
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*/ |
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private function readAhead($token) |
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{ |
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$this->guardAgainstUnexpectedEof($token); |
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$this->guardAgainstInvalidExpression($token); |
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if ($token === '(') { |
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$l = []; |
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while (true) { |
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$token = $this->nextToken(); |
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if ($token === ')') { |
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return $l; |
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} |
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$l[] = $this->readAhead($token); |
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} |
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} |
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if (isset($this->quotes[$token])) { |
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return [$this->quotes[$token], $this->read()]; |
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} |
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return atom($token); |
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} |
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public function read() |
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{ |
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$first = $this->nextToken(); |
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return $first !== false |
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? $this->readAhead($first) |
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: false; |
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} |
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/** |
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* @return bool|string |
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*/ |
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public function nextToken() |
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{ |
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while (true) { |
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if ($this->line === '') { |
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$this->line = fgets($this->file); |
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} |
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if ($this->line === false) { |
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return $this->line; |
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} |
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preg_match($this->tokenizeRegexp, $this->line, $matches); |
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[$_, $token, $this->line] = $matches; |
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if ($token !== ';' || $token !== '') { |
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return $token; |
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} |
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} |
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} |
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/** |
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* @param $token |
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* @throws \Exception |
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*/ |
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private function guardAgainstUnexpectedEof($token): void |
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{ |
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if ($token === false) { |
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throw new \Exception('unexpected eof!'); |
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} |
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} |
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/** |
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* @param $token |
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* @throws \Exception |
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*/ |
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private function guardAgainstInvalidExpression($token): void |
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{ |
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if ($token === ')') { |
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throw new \Exception('unexpected end of expression'); |
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} |
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} |
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} |
mattwellss /
sphpeme
This check looks for function or method calls that always return null and whose return value is used.
The method
getObject()can return nothing but null, so it makes no sense to use the return value.The reason is most likely that a function or method is imcomplete or has been reduced for debug purposes.