svoid tok_for_unpair(LS tok) {
  jreplace(tok, "for (unpair <id> <id>, <id> :", "for (unpair $4 $5, $4 $7 :");
  jreplace(tok, "for (<id> <id>, <id> : unpair", "for (unpair $3 $4, $3 $6 :");
  jreplace(tok, "for (<id> <id>, <id> <id> : unpair", "for (unpair $3 $4, $6 $7 :");
  
  int i = -1;
  while ((i = jfind(tok, i+1, "for (unpair <id> <id>, <id> <id> :")) >= 0) {
    S type1 = tok.get(i+6), var1 = tok.get(i+8);
    S type2 = tok.get(i+12), var2 = tok.get(i+14);
    int iColon = indexOf(tok, ":", i);
    int iClosing = findEndOfBracketPart(tok, iColon)-1;
    int iCurly = iClosing+2;
    tok_statementToBlock(tok, iCurly);
    S pairVar = makeVar();
    replaceTokens(tok, i+4, iColon-1, tok_toNonPrimitiveTypes("Pair<" + type1 + ", " + type2 + ">") + " " + pairVar);
    tok.set(iCurly, "{ "
      + type1 + " " + var1 + " = pairA(" + pairVar + "); "
      + type2 + " " + var2 + " = pairB(" + pairVar + "); ");
    reTok(tok, i, iCurly+1);
  }
  
  // typeless version
  
  i = -1;
  while ((i = jfind(tok, i+1, "for (<id>, <id> : unpair")) >= 0) {
    S var1 = tok.get(i+4);
    S var2 = tok.get(i+8);
    int iColon = indexOf(tok, ":", i);
    int iClosing = findEndOfBracketPart(tok, iColon)-1;
    int iCurly = iClosing+2;
    tok_statementToBlock(tok, iCurly);
    S pairVar = makeVar();
    replaceTokens(tok, i+4, iColon+3, "var " + pairVar + ":");
    tok.set(iCurly, "{ "
      + "var " + var1 + " = pairA(" + pairVar + "); "
      + "var " + var2 + " = pairB(" + pairVar + "); ");
    reTok(tok, i, iCurly+1);
  }
}