(* 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 debug = false
   
   let out s = if debug then prerr_endline s
}

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