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   1  <?php
   2  
   3  /**
   4   * Quickie parser class that can happily read the subset of PHP we need
   5   * for our localization arrays safely.
   6   *
   7   * Still an order of magnitude slower than eval().
   8   */
   9  class QuickArrayReader {
  10      private $vars = array();
  11  
  12      /**
  13       * @param $string string
  14       */
  15  	function __construct( $string ) {
  16          $scalarTypes = array(
  17              T_LNUMBER => true,
  18              T_DNUMBER => true,
  19              T_STRING => true,
  20              T_CONSTANT_ENCAPSED_STRING => true,
  21          );
  22          $skipTypes = array(
  23              T_WHITESPACE => true,
  24              T_COMMENT => true,
  25              T_DOC_COMMENT => true,
  26          );
  27          $tokens = token_get_all( $string );
  28          $count = count( $tokens );
  29          for ( $i = 0; $i < $count; ) {
  30              while ( isset( $skipTypes[$tokens[$i][0]] ) ) {
  31                  $i++;
  32              }
  33              switch ( $tokens[$i][0] ) {
  34                  case T_OPEN_TAG:
  35                      $i++;
  36                      continue;
  37                  case T_VARIABLE:
  38                      // '$messages' -> 'messages'
  39                      $varname = trim( substr( $tokens[$i][1], 1 ) );
  40                      $varindex = null;
  41  
  42                      while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  43  
  44                      if ( $tokens[$i] === '[' ) {
  45                          while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  46  
  47                          if ( isset( $scalarTypes[$tokens[$i][0]] ) ) {
  48                              $varindex = $this->parseScalar( $tokens[$i] );
  49                          } else {
  50                              throw $this->except( $tokens[$i], 'scalar index' );
  51                          }
  52                          while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  53  
  54                          if ( $tokens[$i] !== ']' ) {
  55                              throw $this->except( $tokens[$i], ']' );
  56                          }
  57                          while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  58                      }
  59  
  60                      if ( $tokens[$i] !== '=' ) {
  61                          throw $this->except( $tokens[$i], '=' );
  62                      }
  63                      while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  64  
  65                      if ( isset( $scalarTypes[$tokens[$i][0]] ) ) {
  66                          $buildval = $this->parseScalar( $tokens[$i] );
  67                      } elseif ( $tokens[$i][0] === T_ARRAY ) {
  68                          while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  69                          if ( $tokens[$i] !== '(' ) {
  70                              throw $this->except( $tokens[$i], '(' );
  71                          }
  72                          $buildval = array();
  73                          do {
  74                              while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  75  
  76                              if ( $tokens[$i] === ')' ) {
  77                                  break;
  78                              }
  79                              if ( isset( $scalarTypes[$tokens[$i][0]] ) ) {
  80                                  $key = $this->parseScalar( $tokens[$i] );
  81                              }
  82                              while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  83  
  84                              if ( $tokens[$i][0] !== T_DOUBLE_ARROW ) {
  85                                  throw $this->except( $tokens[$i], '=>' );
  86                              }
  87                              while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  88  
  89                              if ( isset( $scalarTypes[$tokens[$i][0]] ) ) {
  90                                  $val = $this->parseScalar( $tokens[$i] );
  91                              }
  92                              wfSuppressWarnings();
  93                              $buildval[$key] = $val;
  94                              wfRestoreWarnings();
  95                              while ( isset( $skipTypes[$tokens[++$i][0]] ) );
  96  
  97                              if ( $tokens[$i] === ',' ) {
  98                                  continue;
  99                              } elseif ( $tokens[$i] === ')' ) {
 100                                  break;
 101                              } else {
 102                                  throw $this->except( $tokens[$i], ', or )' );
 103                              }
 104                          } while ( true );
 105                      } else {
 106                          throw $this->except( $tokens[$i], 'scalar or array' );
 107                      }
 108                      if ( is_null( $varindex ) ) {
 109                          $this->vars[$varname] = $buildval;
 110                      } else {
 111                          wfSuppressWarnings();
 112                          $this->vars[$varname][$varindex] = $buildval;
 113                          wfRestoreWarnings();
 114                      }
 115                      while ( isset( $skipTypes[$tokens[++$i][0]] ) );
 116                      if ( $tokens[$i] !== ';' ) {
 117                          throw $this->except( $tokens[$i], ';' );
 118                      }
 119                      $i++;
 120                      break;
 121                  default:
 122                      throw $this->except( $tokens[$i], 'open tag, whitespace, or variable.' );
 123              }
 124          }
 125      }
 126  
 127      /**
 128       * @param $got string
 129       * @param $expected string
 130       * @return Exception
 131       */
 132  	private function except( $got, $expected ) {
 133          if ( is_array( $got ) ) {
 134              $got = token_name( $got[0] ) . " ('" . $got[1] . "')";
 135          } else {
 136              $got = "'" . $got . "'";
 137          }
 138  
 139          return new Exception( "Expected $expected, got $got" );
 140      }
 141  
 142      /**
 143       * Parse a scalar value in PHP
 144       *
 145       * @param $token string
 146       *
 147       * @return mixed Parsed value
 148       */
 149  	function parseScalar( $token ) {
 150          if ( is_array( $token ) ) {
 151              $str = $token[1];
 152          } else {
 153              $str = $token;
 154          }
 155          if ( $str !== '' && $str[0] == '\'' ) {
 156              // Single-quoted string
 157              // @fixme trim() call is due to mystery bug where whitespace gets
 158              // appended to the token; without it we ended up reading in the
 159              // extra quote on the end!
 160              return strtr( substr( trim( $str ), 1, -1 ),
 161                  array( '\\\'' => '\'', '\\\\' => '\\' ) );
 162          }
 163  
 164          wfSuppressWarnings();
 165          if ( $str !== '' && $str[0] == '"' ) {
 166              // Double-quoted string
 167              // @fixme trim() call is due to mystery bug where whitespace gets
 168              // appended to the token; without it we ended up reading in the
 169              // extra quote on the end!
 170              wfRestoreWarnings();
 171              return stripcslashes( substr( trim( $str ), 1, -1 ) );
 172          }
 173          wfRestoreWarnings();
 174  
 175          if ( substr( $str, 0, 4 ) === 'true' ) {
 176              return true;
 177          }
 178  
 179          if ( substr( $str, 0, 5 ) === 'false' ) {
 180              return false;
 181          }
 182  
 183          if ( substr( $str, 0, 4 ) === 'null' ) {
 184              return null;
 185          }
 186  
 187          // Must be some kind of numeric value, so let PHP's weak typing
 188          // be useful for a change
 189          return $str;
 190      }
 191  
 192      /**
 193       * @param $varname string
 194       * @return null|string
 195       */
 196  	function getVar( $varname ) {
 197          if ( isset( $this->vars[$varname] ) ) {
 198              return $this->vars[$varname];
 199          } else {
 200              return null;
 201          }
 202      }
 203  }
 204