(* Copyright (C) 2000, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * HELM is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://cs.unibo.it/helm/.
 *)

(******************************************************************************)
(*                                                                            *)
(*                               PROJECT HELM                                 *)
(*                                                                            *)
(*                     Ferruccio Guidi <fguidi@cs.unibo.it>                   *)
(*                                 23/05/2002                                 *)
(*                                                                            *)
(*                                                                            *)
(******************************************************************************)

{ 
   open MQueryTParser
}

let SPC   = [' ' '\t' '\n']+
let ALPHA = ['A'-'Z' 'a'-'z']
let NUM   = ['0'-'9']
let IDEN  = ALPHA (NUM | ALPHA)*
let QSTR  = [^ '"' '\\']+

rule comm_token = parse
   | "*)"        { query_token lexbuf }
   | [^ '*']*    { comm_token lexbuf }
and string_token = parse
   | '"'         { DQ  }
   | '\\' _      { STR (String.sub (Lexing.lexeme lexbuf) 1 1) }
   | QSTR        { STR (Lexing.lexeme lexbuf) }
   | eof         { EOF }
and query_token = parse
   | "(*"        { comm_token lexbuf }
   | SPC         { query_token lexbuf }
   | '"'         { STR (qstr string_token lexbuf) }
   | '('         { LP }
   | ')'         { RP }
   | '{'         { LC }
   | '}'         { RC }
   | '@'         { AT }
   | '%'         { PC }
   | '$'         { DL }
   | '.'         { FS }
   | ','         { CM }
   | '/'         { SL }
   | "and"       { AND    }
   | "attr"      { ATTR   }
   | "attribute" { ATTRIB }
   | "be"        { BE     }
   | "diff"      { DIFF   }
   | "eq"        { EQ     }
   | "ex"        { EX     }
   | "false"     { FALSE  }
   | "fun"       { FUN    }
   | "in"        { IN     }
   | "intersect" { INTER  }
   | "inverse"   { INV    }
   | "let"       { LET    }
   | "meet"      { MEET   }
   | "not"       { NOT    }
   | "or"        { OR     }
   | "pattern"   { PAT    }
   | "ref"       { REF    }
   | "refof"     { REFOF  }
   | "relation"  { REL    }
   | "select"    { SELECT }
   | "sub"       { SUB    }
   | "super"     { SUPER  }
   | "true"      { TRUE   }
   | "union"     { UNION  }
   | "where"     { WHERE  }
   | IDEN        { ID (Lexing.lexeme lexbuf) }
   | eof         { EOF    }
and result_token = parse
   | SPC         { result_token lexbuf }
   | '"'         { STR (qstr string_token lexbuf) }
   | '{'         { LC }
   | '}'         { RC }
   | ','         { CM }
   | ';'         { SC }
   | '='         { IS }
   | "attr"      { ATTR   }
   | eof         { EOF    }