The Double Metaphone Search Algorithm

Figure 1: The part of the Double Metaphone algorithm that processes the letter 'C'

case 'C':
   if((current > 1  )//various germanic
      AND !IsVowel(current - 2) 
      AND StringAt((current - 1), 3, "ACH", "") 
      AND ((GetAt(current + 2) != 'I') 
           AND ((GetAt(current + 2) != 'E') 
      OR StringAt((current - 2), 6, "BACHER", "MACHER", "")) )) {
         MetaphAdd("K"); current +=2; break;
   }
   //special case 'caesar'
   if((current == 0) AND StringAt(current, 6, "CAESAR", "")) {  
      MetaphAdd("S"); current +=2; break;
   }
   if(StringAt(current, 4, "CHIA", "")) {  //italian 'chianti'
      MetaphAdd("K"); current +=2; break;
   }
   if(StringAt(current, 2, "CH", "")) {    
      //find 'michael'
      if((current > 0) AND StringAt(current, 4, "CHAE", "")) {  
         MetaphAdd("K", "X"); current +=2; break;
      }
      if((current == 0)  //greek roots e.g. 'chemistry', 'chorus'
         AND (StringAt((current + 1), 5, "HARAC", "HARIS", "") 
         OR StringAt((current + 1), 3, "HOR", 
                     "HYM", "HIA", "HEM", ""))
         AND !StringAt(0, 5, "CHORE", "")) {

         MetaphAdd("K"); current +=2; break;
      }
      //germanic, greek, or otherwise 'ch' for 'kh' sound
      if((StringAt(0, 4, "VAN ", "VON ", "") 
         OR StringAt(0, 3, "SCH", "")) 

         // 'architect but not 'arch', 'orchestra', 'orchid'
         OR StringAt((current - 2), 6, "ORCHES", "ARCHIT", 
                     "ORCHID")
         OR StringAt((current + 2), 1, "T", "S", "")
         OR ((StringAt((current - 1), 1, "A", "O", "U", "E", "") 
             OR (current == 0))

         //e.g., 'wachtler', 'wechsler', but not 'tichner'
         AND StringAt((current + 2), 1, "L", "R", "N", "M", "B", 
                      "H", "F", "V", "W", " ", ""))) {  
         MetaphAdd("K");
      } else {    
         if(current > 0) {
            if(StringAt(0, 2, "MC", ""))  //e.g., "McHugh"
               MetaphAdd("K"); 
            else MetaphAdd("X", "K");
         }
            else  MetaphAdd("X");
      }
         current +=2; break;
   }
   //e.g, 'czerny'
   if(StringAt(current, 2, "CZ", "") 
      AND !StringAt((current - 2), 4, "WICZ", "")) { 
         MetaphAdd("S", "X"); current += 2; break;
   }
   //e.g., 'focaccia'
   if(StringAt((current + 1), 3, "CIA", "")) {  
      MetaphAdd("X"); current += 3; break;
   }
   //double 'C', but not if e.g. 'McClellan'
   if(StringAt(current, 2, "CC", "") AND !((current == 1) 
      AND (GetAt(0) == 'M')))  
      //'bellocchio' but not 'bacchus'
      if(StringAt((current + 2), 1, "I", "E", "H") 
         AND !StringAt((current + 2), 2, "HU", "")) {  
            
         //'accident', 'accede' 'succeed'
         if(((current == 1) AND (GetAt(current - 1) == 'A')) 
            OR StringAt((current - 1), 5, "UCCEE", "UCCES", ""))
                
            MetaphAdd("KS");
         else  //'bacci', 'bertucci', other italian
            MetaphAdd("X");
            
         current += 3; break;
      } else {//Pierce's rule
         MetaphAdd("K"); current += 2; break;
      }
   if(StringAt(current, 2, "CK", "CG", "CQ", "")) {
      MetaphAdd("K"); current += 2; break;
   }
   if(StringAt(current, 2, "CI", "CE", "CY", "")) {
      //italian vs. english
      if(StringAt(current, 3, "CIO", "CIE", "CIA", ""))  
         MetaphAdd("S", "X");
      else
         MetaphAdd("S");
      current += 2; break;
   }  //else
   MetaphAdd("K");

   //name sent in 'mac caffrey', 'mac gregor
   if(StringAt((current + 1), 2, " C", " Q", " G", ""))  
      current += 3;
   else
      if(StringAt((current + 1), 1, "C", "K", "Q", "") 
         AND !StringAt((current + 1), 2, "CE", "CI", ""))

         current += 2; else current += 1;
   break;