ezyacclib.pas

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Unit EzYacclib;

(* Yacc Library Unit for TP Yacc Version 3.0, 6-17-91 AG *)
(* adapted to Delphi 3,4,5 4/15/2001 *)

Interface

Uses EzLexLib;

Const
  yymaxdepth = 2048;
  (* default stack size of parser *)

Type
  YYSType = Integer;
  TYYFlag = ( yyfnone, yyfaccept, yyfabort, yyferror );

  (* default value type, may be redefined in Yacc output file *)
  TCustomParser = Class( TObject )
  Protected
    yyerrflag: Integer;
    yyflag: TYYFlag;
  Public
    yychar: Integer; (* current lookahead character *)
    yynerrs: Integer; (* current number of syntax errors reported by the
    parser *)
    yydebug: Boolean; (* set to true to enable debugging output of parser *)

    yyLexer: TCustomLexer; (* Lexer used to lex input *)

    yyerrormsg: String; (* Last error message in string format *)

    Procedure yyerror( const msg: String );
    (* error message printing routine used by the parser *)

    Procedure yyclearin;
    (* delete the current lookahead token *)

    Procedure yyaccept;
    (* trigger accept action of the parser; yyparse accepts returning 0, as if
       it reached end of input *)

    Procedure yyabort;
    (* like yyaccept, but causes parser to return with value 1, as if an
       unrecoverable syntax error had been encountered *)

    Procedure yyerrlab;
    (* causes error recovery to be started, as if a syntax error had been
       encountered *)

    Procedure yyerrok;
    (* when in error mode, resets the parser to its normal mode of
       operation *)

    Function yyparse: integer; Virtual; Abstract;

    (* Flags used internally by the parser routine: *)

  End; (* TCustomParser *)

Implementation

Procedure TCustomParser.yyerror( const msg: String );
Begin
  yyerrormsg := msg;
  //writeln(yyLexer.yyerrorfile, msg);
End (*yyerrmsg*);

Procedure TCustomParser.yyclearin;
Begin
  yychar := -1;
End (*yyclearin*);

Procedure TCustomParser.yyaccept;
Begin
  yyflag := yyfaccept;
End (*yyaccept*);

Procedure TCustomParser.yyabort;
Begin
  yyflag := yyfabort;
End (*yyabort*);

Procedure TCustomParser.yyerrlab;
Begin
  yyflag := yyferror;
End (*yyerrlab*);

Procedure TCustomParser.yyerrok;
Begin
  yyerrflag := 0;
End (*yyerrork*);

End (*YaccLib*).