ROMAN                                                            7-SEP-1988 10:33:35    VAX SCAN   V1.1-008                 Page 1
                                                                 7-SEP-1988 10:33:32    ISD$:[SCN.PARSER]ROMAN.SCN;5 (1)



    1         	MODULE roman;
    2         	 
    3         		!
    4         		!	This module defines the subroutine that 
    5         		!	checks and evaluate a roman numeral.
    6         		!
    7         		!	The integer result is:
    8         		!	    if positive, the resultant numerical value
    9         		!	    if negative, the absolute value is the column
   10         		!	    at which the parsing error was detected
   11         		!
   12         	 
   13         	INCLUDE FILE 'sysdeflib$:recovery_packet.scndef';
   35         	INCLUDE FILE 'roman.def';
   55         	 
   56         	PROCEDURE report_roman_error ( error_packet: recovery_packet );
   57         		roman_value = - ( error_packet.error_token_column - 1 );
   58         		END PROCEDURE; /* report_roman_error
   59         	 
   60         	TOKEN rn_m { 'm' };
   61         	TOKEN rn_d { 'd' };
   62         	TOKEN rn_c { 'c' };
   63         	TOKEN rn_l { 'l' };
   64         	TOKEN rn_x { 'x' };
   65         	TOKEN rn_v { 'v' };
   66         	TOKEN rn_i { 'i' };
   67         	TOKEN rc_cm { 'cm' };
   68         	TOKEN rc_cd { 'cd' };
   69         	TOKEN rc_xc { 'xc' };
   70         	TOKEN rc_xl { 'xl' };
   71         	TOKEN rc_ix { 'ix' };
   72         	TOKEN rc_iv { 'iv' };
   73         	TOKEN sos { S'SOS' };
   74         	TOKEN eos { S'EOS' };
   75         	TOKEN eol { S'EOL' };
   76         	 
   77         	MACRO m SYNTAX { rn_m };
   78         		roman_value = roman_value + 1000;
   79         		END MACRO; /* m
   80         	MACRO d SYNTAX { rn_d };
   81         		roman_value = roman_value + 500;
   82         		END MACRO; /* d
   83         	MACRO c SYNTAX { rn_c };
   84         		roman_value = roman_value + 100;
   85         		END MACRO; /* c
   86         	MACRO l SYNTAX { rn_l };
   87         		roman_value = roman_value + 50;
   88         		END MACRO; /* l
   89         	MACRO x SYNTAX { rn_x };

ROMAN                                                            7-SEP-1988 10:33:35    VAX SCAN   V1.1-008                 Page 2
                                                                 7-SEP-1988 10:33:32    ISD$:[SCN.PARSER]ROMAN.SCN;5 (1)

   90         		roman_value = roman_value + 10;
   91         		END MACRO; /* x
   92         	MACRO v SYNTAX { rn_v };
   93         		roman_value = roman_value + 5;
   94         		END MACRO; /* v
   95         	MACRO i SYNTAX { rn_i };
   96         		roman_value = roman_value + 1;
   97         		END MACRO; /* i
   98         	MACRO cm SYNTAX { rc_cm };
   99         		roman_value = roman_value + 900;
  100         		END MACRO; /* cm
  101         	MACRO cd SYNTAX { rc_cd };
  102         		roman_value = roman_value + 400;
  103         		END MACRO; /* cd
  104         	MACRO xc SYNTAX { rc_xc };
  105         		roman_value = roman_value + 90;
  106         		END MACRO; /* xc
  107         	MACRO xl SYNTAX { rc_xl };
  108         		roman_value = roman_value + 40;
  109         		END MACRO; /* xl
  110         	MACRO ix SYNTAX { rc_ix };
  111         		roman_value = roman_value + 9;
  112         		END MACRO; /* ix
  113         	MACRO iv SYNTAX { rc_iv };
  114         		roman_value = roman_value + 4;
  115         		END MACRO; /* iv
  116         	 
  117         	MACRO c_s SYNTAX { c [ c [ c [ c ] ] ] };
  118         		END MACRO; /* c_s
  119         	 
  120         	MACRO x_s SYNTAX { x [ x [ x [ x ] ] ] };
  121         		END MACRO; /* x_s
  122         	 
  123         	MACRO i_s SYNTAX { i [ i [ i [ i ] ] ] };
  124         		END MACRO; /* i_s
  125         	 
  126         	MACRO under_10 SYNTAX { v [ i_s ] | i_s | iv | ix };
  127         		END MACRO; /* under_10
  128         	 
  129         	MACRO under_100 SYNTAX { l [ x_s ] | x_s | xl | xc };
  130         		END MACRO; /* under_100
  131         	 
  132         	MACRO under_1000 SYNTAX { d [ c_s ] | c_s | cm | cd };
  133         		END MACRO; /* under_1000
  134         	 
  135         	MACRO roman_numeral TRIGGER { sos ERROR( report_roman_error ) : 
  136         	    { [ m | m m ] [ under_1000 ] [ under_100 ] [ under_10 ] eol } eos };
  137         		ANSWER S'EOS';
  138         		END MACRO; /* roman_numeral
  139         	 
  140         	PROCEDURE roman_evaluate ( rnp: STRING ) OF INTEGER;

ROMAN                                                            7-SEP-1988 10:33:35    VAX SCAN   V1.1-008                 Page 3
                                                                 7-SEP-1988 10:33:32    ISD$:[SCN.PARSER]ROMAN.SCN;5 (1)

  141         		DECLARE rnp_lower: STRING;
  142         	 
  143         		roman_value = 0;
  144         		rnp_lower = LOWER(rnp) & S'EOL';
  145         		START SCAN INPUT STRING rnp_lower OUTPUT FILE 'nl:';
  146         	 
  147         		RETURN roman_value;
  148         		END PROCEDURE; /* roman_evaluate
  149         	 
  150         	END MODULE; /* roman


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