1 <?php
  2 
  3 /**
  4  * A tokenised regular expression is a parser, similar to a regular expression, that acts on tokens rather than characters.
  5  * This is a crucial component of the ManifestBuilder.
  6  * @package sapphire
  7  * @subpackage core
  8  */ 
  9 class TokenisedRegularExpression extends Object {
 10     /**
 11      * The regular expression definition
 12      */
 13     protected $expression;
 14     
 15     function __construct($expression) {
 16         $this->expression = $expression;
 17         parent::__construct();
 18     }
 19     
 20     function findAll($tokens) {
 21         $tokenTypes = array();
 22         foreach($tokens as $i => $token) {
 23             if(is_array($token)) {
 24                 $tokenTypes[$i] = $token[0];
 25             } else {
 26                 $tokenTypes[$i] = $token;
 27                 // Pre-process string tokens for matchFrom()
 28                 $tokens[$i] = array($token, $token);
 29             }
 30         }
 31         
 32         $startKeys = array_keys($tokenTypes, $this->expression[0]); 
 33         $allMatches = array();
 34         
 35         foreach($startKeys as $startKey) {
 36             $matches = array();
 37             if($this->matchFrom($startKey, 0, $tokens, $matches)) {
 38                 $allMatches[] = $matches;
 39             }
 40         }
 41         return $allMatches;
 42     }
 43     
 44     function matchFrom($tokenPos, $expressionPos, &$tokens, &$matches) {
 45         $expressionRule = $this->expression[$expressionPos];
 46         $expectation = is_array($expressionRule) ? $expressionRule[0] : $expressionRule;
 47         if(!is_array($expressionRule)) $expressionRule = array();
 48         
 49         if($expectation == $tokens[$tokenPos][0]) {
 50             if(isset($expressionRule['save_to'])) {
 51                 // Append to an array
 52                 if(substr($expressionRule['save_to'],-2) == '[]') $matches[substr($expressionRule['save_to'],0,-2)][] = $tokens[$tokenPos][1];
 53                 // Regular variable setting
 54                 else $matches[$expressionRule['save_to']] = $tokens[$tokenPos][1];
 55             }
 56             
 57             // End of the expression
 58             if(!isset($this->expression[$expressionPos+1])) {
 59                 return true;
 60             
 61             // Process next step as normal
 62             } else if($this->matchFrom($tokenPos+1, $expressionPos+1, $tokens, $matches)) {
 63                 return true;
 64 
 65             // This step is optional
 66             } else if(isset($expressionRule['optional']) && $this->matchFrom($tokenPos, $expressionPos+1, $tokens, $matches)) {
 67                 return true;
 68 
 69             // Process jumps
 70             } else if(isset($expressionRule['can_jump_to'])) {
 71                 if(is_array($expressionRule['can_jump_to'])) foreach($expressionRule['can_jump_to'] as $canJumpTo) {
 72                     // can_jump_to & optional both set
 73                     if(isset($expressionRule['optional']) && $this->matchFrom($tokenPos, $canJumpTo, $tokens, $matches)) {
 74                         return true;
 75                     }
 76                     // can_jump_to set (optional may or may not be set)
 77                     if($this->matchFrom($tokenPos+1, $canJumpTo, $tokens, $matches)) {
 78                         return true;
 79                     }
 80 
 81                 } else {
 82                     // can_jump_to & optional both set
 83                     if(isset($expressionRule['optional']) && $this->matchFrom($tokenPos, $expressionRule['can_jump_to'], $tokens, $matches)) {
 84                         return true;
 85                     }
 86                     // can_jump_to set (optional may or may not be set)
 87                     if($this->matchFrom($tokenPos+1, $expressionRule['can_jump_to'], $tokens, $matches)) {
 88                         return true;
 89                     }
 90                 }
 91             }
 92 
 93         } else if(isset($expressionRule['optional'])) {
 94             if(isset($this->expression[$expressionPos+1])) return $this->matchFrom($tokenPos, $expressionPos+1, $tokens, $matches);
 95             else return true;
 96         }
 97 
 98         return false;
 99         
100     }
101 }