original_string: public function validate($value, Constraint $constraint)
      {
          if (!$constraint instanceof Luhn) {
              throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\Luhn');
          }
  
          if (null === $value || '' === $value) {
              return;
          }
  
          // Work with strings only, because long numbers are represented as floats
          // internally and don't work with strlen()
          if (!\is_string($value) && !(\is_object($value) && method_exists($value, '__toString'))) {
              throw new UnexpectedValueException($value, 'string');
          }
  
          $value = (string) $value;
  
          if (!ctype_digit($value)) {
              $this->context->buildViolation($constraint->message)
                  ->setParameter('{{ value }}', $this->formatValue($value))
                  ->setCode(Luhn::INVALID_CHARACTERS_ERROR)
                  ->addViolation();
  
              return;
          }
  
          $checkSum = 0;
          $length = \strlen($value);
  
          // Starting with the last digit and walking left, add every second
          // digit to the check sum
          // e.g. 7  9  9  2  7  3  9  8  7  1  3
          //      ^     ^     ^     ^     ^     ^
          //    = 7  +  9  +  7  +  9  +  7  +  3
          for ($i = $length - 1; $i >= 0; $i -= 2) {
              $checkSum += $value[$i];
          }
  
          // Starting with the second last digit and walking left, double every
          // second digit and add it to the check sum
          // For doubles greater than 9, sum the individual digits
          // e.g. 7  9  9  2  7  3  9  8  7  1  3
          //         ^     ^     ^     ^     ^
          //    =    1+8 + 4  +  6  +  1+6 + 2
          for ($i = $length - 2; $i >= 0; $i -= 2) {
              $checkSum += array_sum(str_split($value[$i] * 2));
          }
  
          if (0 === $checkSum || 0 !== $checkSum % 10) {
              $this->context->buildViolation($constraint->message)
                  ->setParameter('{{ value }}', $this->formatValue($value))
                  ->setCode(Luhn::CHECKSUM_FAILED_ERROR)
                  ->addViolation();
          }
      }
code: public function validate($value, Constraint $constraint)
      {
          if (!$constraint instanceof Luhn) {
              throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\Luhn');
          }
  
          if (null === $value || '' === $value) {
              return;
          }
  
          // Work with strings only, because long numbers are represented as floats
          // internally and don't work with strlen()
          if (!\is_string($value) && !(\is_object($value) && method_exists($value, '__toString'))) {
              throw new UnexpectedValueException($value, 'string');
          }
  
          $value = (string) $value;
  
          if (!ctype_digit($value)) {
              $this->context->buildViolation($constraint->message)
                  ->setParameter('{{ value }}', $this->formatValue($value))
                  ->setCode(Luhn::INVALID_CHARACTERS_ERROR)
                  ->addViolation();
  
              return;
          }
  
          $checkSum = 0;
          $length = \strlen($value);
  
          // Starting with the last digit and walking left, add every second
          // digit to the check sum
          // e.g. 7  9  9  2  7  3  9  8  7  1  3
          //      ^     ^     ^     ^     ^     ^
          //    = 7  +  9  +  7  +  9  +  7  +  3
          for ($i = $length - 1; $i >= 0; $i -= 2) {
              $checkSum += $value[$i];
          }
  
          // Starting with the second last digit and walking left, double every
          // second digit and add it to the check sum
          // For doubles greater than 9, sum the individual digits
          // e.g. 7  9  9  2  7  3  9  8  7  1  3
          //         ^     ^     ^     ^     ^
          //    =    1+8 + 4  +  6  +  1+6 + 2
          for ($i = $length - 2; $i >= 0; $i -= 2) {
              $checkSum += array_sum(str_split($value[$i] * 2));
          }
  
          if (0 === $checkSum || 0 !== $checkSum % 10) {
              $this->context->buildViolation($constraint->message)
                  ->setParameter('{{ value }}', $this->formatValue($value))
                  ->setCode(Luhn::CHECKSUM_FAILED_ERROR)
                  ->addViolation();
          }
      }
code_tokens: public function validate ( $ value , Constraint $ constraint ) { if ( ! $ constraint instanceof Luhn ) { throw new UnexpectedTypeException ( $ constraint , __NAMESPACE__ . '\Luhn' ) ; } if ( null === $ value || '' === $ value ) { return ; } // Work with strings only, because long numbers are represented as floats // internally and don't work with strlen() if ( ! \ is_string ( $ value ) && ! ( \ is_object ( $ value ) && method_exists ( $ value , '__toString' ) ) ) { throw new UnexpectedValueException ( $ value , 'string' ) ; } $ value = ( string ) $ value ; if ( ! ctype_digit ( $ value ) ) { $ this -> context -> buildViolation ( $ constraint -> message ) -> setParameter ( '{{ value }}' , $ this -> formatValue ( $ value ) ) -> setCode ( Luhn :: INVALID_CHARACTERS_ERROR ) -> addViolation ( ) ; return ; } $ checkSum = 0 ; $ length = \ strlen ( $ value ) ; // Starting with the last digit and walking left, add every second // digit to the check sum // e.g. 7  9  9  2  7  3  9  8  7  1  3 //      ^     ^     ^     ^     ^     ^ //    = 7  +  9  +  7  +  9  +  7  +  3 for ( $ i = $ length - 1 ; $ i >= 0 ; $ i -= 2 ) { $ checkSum += $ value [ $ i ] ; } // Starting with the second last digit and walking left, double every // second digit and add it to the check sum // For doubles greater than 9, sum the individual digits // e.g. 7  9  9  2  7  3  9  8  7  1  3 //         ^     ^     ^     ^     ^ //    =    1+8 + 4  +  6  +  1+6 + 2 for ( $ i = $ length - 2 ; $ i >= 0 ; $ i -= 2 ) { $ checkSum += array_sum ( str_split ( $ value [ $ i ] * 2 ) ) ; } if ( 0 === $ checkSum || 0 !== $ checkSum % 10 ) { $ this -> context -> buildViolation ( $ constraint -> message ) -> setParameter ( '{{ value }}' , $ this -> formatValue ( $ value ) ) -> setCode ( Luhn :: CHECKSUM_FAILED_ERROR ) -> addViolation ( ) ; } }
docstring: Validates a credit card number with the Luhn algorithm.
  
  @param mixed      $value
  @param Constraint $constraint
  
  @throws UnexpectedTypeException when the given credit card number is no string
docstring_tokens: Validates a credit card number with the Luhn algorithm .