external/bsd/flex/dist/examples/manual/dates.lex

   1 /*
   2  * dates.lex: An example of using start states to
   3  *            distinguish between different date formats.
   4  */
   5
   6 %{
   7 #include <ctype.h>
   8
   9 char month[20],dow[20],day[20],year[20];
  10
  11 %}
  12
  13 skip        of|the|[ \t,]*
  14
  15 mon         (mon(day)?)
  16 tue         (tue(sday)?)
  17 wed         (wed(nesday)?)
  18 thu         (thu(rsday)?)
  19 fri         (fri(day)?)
  20 sat         (sat(urday)?)
  21 sun         (sun(day)?)
  22
  23 day_of_the_week ({mon}|{tue}|{wed}|{thu}|{fri}|{sat}|{sun})
  24
  25 jan         (jan(uary)?)
  26 feb         (feb(ruary)?)
  27 mar         (mar(ch)?)
  28 apr         (apr(il)?)
  29 may         (may)
  30 jun         (jun(e)?)
  31 jul         (jul(y)?)
  32 aug         (aug(ust)?)
  33 sep         (sep(tember)?)
  34 oct         (oct(ober)?)
  35 nov         (nov(ember)?)
  36 dec         (dec(ember)?)
  37
  38 first_half  ({jan}|{feb}|{mar}|{apr}|{may}|{jun})
  39 second_half ({jul}|{aug}|{sep}|{oct}|{nov}|{dec})
  40 month       {first_half}|{second_half}
  41
  42 nday         [1-9]|[1-2][0-9]|3[0-1]
  43 nmonth       [1-9]|1[0-2]
  44 nyear        [0-9]{1,4}
  45
  46 year_ext    (ad|AD|bc|BC)?
  47 day_ext     (st|nd|rd|th)?
  48
  49 %s LONG SHORT
  50 %s DAY DAY_FIRST YEAR_FIRST YEAR_LAST YFMONTH YLMONTH
  51
  52 %%
  53
  54   /* the default is month-day-year */
  55
  56 <LONG>{day_of_the_week}    strcpy(dow,yytext);
  57 <LONG>{month}              strcpy(month,yytext); BEGIN(DAY);
  58
  59   /* handle the form: day-month-year */
  60
  61 <LONG>{nday}{day_ext}      strcpy(day,yytext);   BEGIN(DAY_FIRST);
  62 <DAY_FIRST>{month}         strcpy(month,yytext); BEGIN(LONG);
  63 <DAY>{nday}{day_ext}       strcpy(day,yytext);   BEGIN(LONG);
  64
  65 <LONG>{nyear}{year_ext}  {
  66                            printf("Long:\n");
  67                            printf("  DOW   : %s \n",dow);
  68                            printf("  Day   : %s \n",day);
  69                            printf("  Month : %s \n",month);
  70                            printf("  Year  : %s \n",yytext);
  71                            strcpy(dow,"");
  72                            strcpy(day,"");
  73                            strcpy(month,"");
  74                          }
  75
  76   /* handle dates of the form: day-month-year */
  77
  78 <SHORT>{nday}              strcpy(day,yytext);  BEGIN(YEAR_LAST);
  79 <YEAR_LAST>{nmonth}        strcpy(month,yytext);BEGIN(YLMONTH);
  80 <YLMONTH>{nyear}           strcpy(year,yytext); BEGIN(SHORT);
  81
  82   /* handle dates of the form: year-month-day */
  83
  84 <SHORT>{nyear}             strcpy(year,yytext); BEGIN(YEAR_FIRST);
  85 <YEAR_FIRST>{nmonth}       strcpy(month,yytext);BEGIN(YFMONTH);
  86 <YFMONTH>{nday}            strcpy(day,yytext);  BEGIN(SHORT);
  87
  88
  89 <SHORT>\n                {
  90                            printf("Short:\n");
  91                            printf("  Day   : %s \n",day);
  92                            printf("  Month : %s \n",month);
  93                            printf("  Year  : %s \n",year);
  94                            strcpy(year,"");
  95                            strcpy(day,"");
  96                            strcpy(month,"");
  97                          }
  98
  99 long\n                      BEGIN(LONG);
 100 short\n                     BEGIN(SHORT);
 101
 102 {skip}*
 103 \n
 104 .
 105
 106