-#define YY_DECL struct tws * dparsetime(char *lexstr)
+
+ /* This is the tricky thing that makes this function cool. We
+ * replace the traditional int yylex(void) declaration with our
+ * dparsetime() declaration, essentially piggy-backing off the
+ * utility of the yylex() function and adding what we need to make
+ * the parsing function useful to us.
+ */
+#define YY_DECL struct tws *dparsetime(char *lexstr)
+
+ /* yyerminate() is called after the input string is matched to
+ * completion (actually, when the lexer reaches an EOF). The only
+ * thing that really needs to be in this macro function is the
+ * return call, which must be substituted inline into dparsetime.
+ */
-#define INIT() { cp = yytext;}
-#define SETWDAY() { cp++; \
- tw.tw_wday= day_map[(cp[0] & 7) + (cp[1] & 4)]; \
- tw.tw_flags &= ~TW_SDAY; tw.tw_flags |= TW_SEXP; \
- SKIPA(); }
-#define SETMON() { cp++; \
- tw.tw_mon = month_map[(cp[0] + cp[1]) & 0x1f]; \
- SKIPA(); }
+/* The SET* macros will parse for the appropriate field, and leave the
+ * cp pointer at the first character after the desired field. Be
+ * careful with variable-length fields or alpha-num mixes.
+
+ * The SKIP* macros skip over characters of a particular class and
+ * leave cp at the position of the first character that doesn't match
+ * that class. Correspondingly, SKIPTO* skips until it reaches a
+ * character of a particular class.
+ */
+
+#define INIT() { cp = yytext;}
+#define SETWDAY() { cp++; \
+ tw.tw_wday= day_map[(cp[0] & 7) + (cp[1] & 4)]; \
+ tw.tw_flags &= ~TW_SDAY; tw.tw_flags |= TW_SEXP; \
+ SKIPA(); }
+#define SETMON() { cp++; \
+ tw.tw_mon = month_map[(cp[0] + cp[1]) & 0x1f]; \
+ SKIPA(); }
- SKIPD(); }
-#define SETYEAR() { tw.tw_year = atoi(cp); \
- SKIPD(); }
-#define SETDAY() { tw.tw_mday = atoi(cp); \
- tw.tw_flags |= TW_YES; \
- SKIPD(); }
-#define SETTIME() { tw.tw_hour = atoi(cp); \
- cp += 2; \
- SKIPTOD(); \
- tw.tw_min = atoi(cp); \
- cp += 2; \
- if(*cp == ':') { tw.tw_sec = atoi(++cp); SKIPD(); } \
- }
-#define SETZONE(x) { tw.tw_zone = ((x)/100)*60+(x)%100; \
- tw.tw_flags |= TW_SZEXP; \
- SKIPD(); }
-#define SETDST() { tw.tw_flags |= TW_DST; }
-#define SKIPD() { while ( isdigit(*cp++) ) ; \
- --cp; }
-#define SKIPTOD() { while ( !isdigit(*cp++) ) ; \
- --cp; }
-#define SKIPA() { while ( isalpha(*cp++) ) ; \
- --cp; }
-#define SKIPTOA() { while ( !isalpha(*cp++) ) ; \
- --cp; }
-#define SKIPSP() { while ( isspace(*cp++) ) ; \
- --cp; }
-#define SKIPTOSP() { while ( !isspace(*cp++) ) ; \
- --cp; }
+ SKIPD(); }
+#define SETYEAR() { tw.tw_year = atoi(cp); \
+ SKIPD(); }
+#define SETDAY() { tw.tw_mday = atoi(cp); \
+ tw.tw_flags |= TW_YES; \
+ SKIPD(); }
+#define SETTIME() { tw.tw_hour = atoi(cp); \
+ cp += 2; \
+ SKIPTOD(); \
+ tw.tw_min = atoi(cp); \
+ cp += 2; \
+ if(*cp == ':') { \
+ tw.tw_sec = atoi(++cp); SKIPD(); } }
+#define SETZONE(x) { tw.tw_zone = ((x)/100)*60+(x)%100; \
+ tw.tw_flags |= TW_SZEXP; \
+ SKIPD(); }
+#define SETDST() { tw.tw_flags |= TW_DST; }
+#define SKIPD() { while ( isdigit(*cp++) ) ; \
+ --cp; }
+#define SKIPTOD() { while ( !isdigit(*cp++) ) ; \
+ --cp; }
+#define SKIPA() { while ( isalpha(*cp++) ) ; \
+ --cp; }
+#define SKIPTOA() { while ( !isalpha(*cp++) ) ; \
+ --cp; }
+#define SKIPSP() { while ( isspace(*cp++) ) ; \
+ --cp; }
+#define SKIPTOSP() { while ( !isspace(*cp++) ) ; \
+ --cp; }
+ /* The year can either be 2 digits, or 4. However, after
+ Y2K, we found that some MUA were reporting the year 100, hence
+ the middle term here. yyterminate() resolves the actual
+ issues with 2-digit years.
+ */
+
- }
-"-"?("ut"|"UT") INIT(); SETZONE(0);
-"-"?("gmt"|"GMT") INIT(); SETZONE(0);
-"-"?("jst"|"JST") INIT(); SETZONE(200);
-"-"?("jdt"|"JDT") INIT(); SETDST(); SETZONE(2);
-"-"?("est"|"EST") INIT(); SETZONE(-500);
-"-"?("edt"|"EDT") INIT(); SETDST(); SETZONE(-500);
-"-"?("cst"|"CST") INIT(); SETZONE(-600);
-"-"?("cdt"|"CDT") INIT(); SETDST(); SETZONE(-600);
-"-"?("mst"|"MST") INIT(); SETZONE(-700);
-"-"?("mdt"|"MDT") INIT(); SETDST(); SETZONE(-700);
-"-"?("pst"|"PST") INIT(); SETZONE(-800);
-"-"?("pdt"|"PDT") INIT(); SETDST(); SETZONE(-800);
-"-"?("nst"|"NST") INIT(); SETZONE(-330);
-"-"?("ast"|"AST") INIT(); SETZONE(-400);
-"-"?("adt"|"ADT") INIT(); SETDST(); SETZONE(-400);
-"-"?("yst"|"YST") INIT(); SETZONE(-900);
-"-"?("ydt"|"YDT") INIT(); SETDST(); SETZONE(-900);
-"-"?("hst"|"HST") INIT(); SETZONE(-1000);
-"-"?("hdt"|"HDT") INIT(); SETDST(); SETZONE(-1000);
-"-"?("bst"|"BST") INIT(); SETDST(); SETZONE(-100);
-[a-i] {
+ }
+"-"?("ut"|"UT") INIT(); SETZONE(0);
+"-"?("gmt"|"GMT") INIT(); SETZONE(0);
+"-"?("jst"|"JST") INIT(); SETZONE(200);
+"-"?("jdt"|"JDT") INIT(); SETDST(); SETZONE(2);
+"-"?("est"|"EST") INIT(); SETZONE(-500);
+"-"?("edt"|"EDT") INIT(); SETDST(); SETZONE(-500);
+"-"?("cst"|"CST") INIT(); SETZONE(-600);
+"-"?("cdt"|"CDT") INIT(); SETDST(); SETZONE(-600);
+"-"?("mst"|"MST") INIT(); SETZONE(-700);
+"-"?("mdt"|"MDT") INIT(); SETDST(); SETZONE(-700);
+"-"?("pst"|"PST") INIT(); SETZONE(-800);
+"-"?("pdt"|"PDT") INIT(); SETDST(); SETZONE(-800);
+"-"?("nst"|"NST") INIT(); SETZONE(-330);
+"-"?("ast"|"AST") INIT(); SETZONE(-400);
+"-"?("adt"|"ADT") INIT(); SETDST(); SETZONE(-400);
+"-"?("yst"|"YST") INIT(); SETZONE(-900);
+"-"?("ydt"|"YDT") INIT(); SETDST(); SETZONE(-900);
+"-"?("hst"|"HST") INIT(); SETZONE(-1000);
+"-"?("hdt"|"HDT") INIT(); SETDST(); SETZONE(-1000);
+"-"?("bst"|"BST") INIT(); SETDST(); SETZONE(-100);
+[a-iA-I] {