[Bug-gnulib] Re: shellutils: date -d 'last june' +'%B %Y' -> May 2004

[Paul Eggert]

Jim Meyering <address@hidden> writes:

>   http://bugs.debian.org/281004

Dates like "last June" never worked as people expected.  "last" was
equivalent to "-1", so "last june" was parsed as "-1 june", which was
equivalent to "30 May", which explains the symptoms the original bug
reporter observed.

Fortunately (:-), these dates weren't documented either.  For now, I
installed the following patch into both gnulib and coreutils; it
causes "last june" to be rejected as a syntax error.  If someone wants
to add support for this usage that'd be even better.

2004-11-16  Paul Eggert  <address@hidden>

        * doc/getdate.texi (General date syntax): "next" is 1, not 2.
        Document that "second" isn't allowed as an ordinal number.
        * lib/getdate.y (tORDINAL): New token.
        (day, relunit): Allow it for relative times.
        (relative_time_table): Use tORDINAL for ordinals.

Index: doc/getdate.texi
===================================================================
RCS file: /fetish/cu/doc/getdate.texi,v
retrieving revision 1.24
diff -p -u -r1.24 getdate.texi
--- doc/getdate.texi    29 Oct 2004 23:43:34 -0000      1.24
+++ doc/getdate.texi    16 Nov 2004 04:48:26 -0000
@@ -89,13 +89,17 @@ many flavors of items:
 @findex first @r{in date strings}
 @findex next @r{in date strings}
 @findex last @r{in date strings}
-A few numbers may be written out in words in most contexts.  This is
+A few ordinal numbers may be written out in words in some contexts.  This is
 most useful for specifying day of the week items or relative items (see
-below).  Here is the list: @samp{first} for 1, @samp{next} for 2,
address@hidden for 3, @samp{fourth} for 4, @samp{fifth} for 5,
+below).  Among the most commonly used ordinal numbers, the word
address@hidden stands for @math{-1}, @samp{this} stands for 0, and
address@hidden and @samp{next} both stand for 1.  Because the word
address@hidden stands for the unit of time there is no way to write the
+ordinal number 2, but for convenience @samp{third} stands for 3,
address@hidden for 4, @samp{fifth} for 5,
 @samp{sixth} for 6, @samp{seventh} for 7, @samp{eighth} for 8,
 @samp{ninth} for 9, @samp{tenth} for 10, @samp{eleventh} for 11 and
address@hidden for 12.  Also, @samp{last} means exactly @math{-1}.
address@hidden for 12.
 
 @cindex months, written-out
 When a month is written this way, it is still considered to be written
Index: lib/getdate.y
===================================================================
RCS file: /fetish/cu/lib/getdate.y,v
retrieving revision 1.89
diff -p -u -r1.89 getdate.y
--- lib/getdate.y       11 Nov 2004 06:07:57 -0000      1.89
+++ lib/getdate.y       16 Nov 2004 04:48:26 -0000
@@ -201,7 +201,8 @@ static int yyerror (parser_control *, ch
 %token tAGO tDST
 
 %token <intval> tDAY tDAY_UNIT tDAYZONE tHOUR_UNIT tLOCAL_ZONE tMERIDIAN
-%token <intval> tMINUTE_UNIT tMONTH tMONTH_UNIT tSEC_UNIT tYEAR_UNIT tZONE
+%token <intval> tMINUTE_UNIT tMONTH tMONTH_UNIT tORDINAL
+%token <intval> tSEC_UNIT tYEAR_UNIT tZONE
 
 %token <textintval> tSNUMBER tUNUMBER
 %token <timespec> tSDECIMAL_NUMBER tUDECIMAL_NUMBER
@@ -317,6 +318,11 @@ day:
        pc->day_ordinal = 1;
        pc->day_number = $1;
       }
+  | tORDINAL tDAY
+      {
+       pc->day_ordinal = $1;
+       pc->day_number = $2;
+      }
   | tUNUMBER tDAY
       {
        pc->day_ordinal = $1.value;
@@ -412,36 +418,48 @@ rel:
   ;
 
 relunit:
-    tUNUMBER tYEAR_UNIT
+    tORDINAL tYEAR_UNIT
+      { pc->rel_year += $1 * $2; }
+  | tUNUMBER tYEAR_UNIT
       { pc->rel_year += $1.value * $2; }
   | tSNUMBER tYEAR_UNIT
       { pc->rel_year += $1.value * $2; }
   | tYEAR_UNIT
       { pc->rel_year += $1; }
+  | tORDINAL tMONTH_UNIT
+      { pc->rel_month += $1 * $2; }
   | tUNUMBER tMONTH_UNIT
       { pc->rel_month += $1.value * $2; }
   | tSNUMBER tMONTH_UNIT
       { pc->rel_month += $1.value * $2; }
   | tMONTH_UNIT
       { pc->rel_month += $1; }
+  | tORDINAL tDAY_UNIT
+      { pc->rel_day += $1 * $2; }
   | tUNUMBER tDAY_UNIT
       { pc->rel_day += $1.value * $2; }
   | tSNUMBER tDAY_UNIT
       { pc->rel_day += $1.value * $2; }
   | tDAY_UNIT
       { pc->rel_day += $1; }
+  | tORDINAL tHOUR_UNIT
+      { pc->rel_hour += $1 * $2; }
   | tUNUMBER tHOUR_UNIT
       { pc->rel_hour += $1.value * $2; }
   | tSNUMBER tHOUR_UNIT
       { pc->rel_hour += $1.value * $2; }
   | tHOUR_UNIT
       { pc->rel_hour += $1; }
+  | tORDINAL tMINUTE_UNIT
+      { pc->rel_minutes += $1 * $2; }
   | tUNUMBER tMINUTE_UNIT
       { pc->rel_minutes += $1.value * $2; }
   | tSNUMBER tMINUTE_UNIT
       { pc->rel_minutes += $1.value * $2; }
   | tMINUTE_UNIT
       { pc->rel_minutes += $1; }
+  | tORDINAL tSEC_UNIT
+      { pc->rel_seconds += $1 * $2; }
   | tUNUMBER tSEC_UNIT
       { pc->rel_seconds += $1.value * $2; }
   | tSNUMBER tSEC_UNIT
@@ -579,21 +597,21 @@ static table const relative_time_table[]
   { "YESTERDAY",tDAY_UNIT,     -1 },
   { "TODAY",   tDAY_UNIT,       0 },
   { "NOW",     tDAY_UNIT,       0 },
-  { "LAST",    tUNUMBER,       -1 },
-  { "THIS",    tUNUMBER,        0 },
-  { "NEXT",    tUNUMBER,        1 },
-  { "FIRST",   tUNUMBER,        1 },
-/*{ "SECOND",  tUNUMBER,        2 }, */
-  { "THIRD",   tUNUMBER,        3 },
-  { "FOURTH",  tUNUMBER,        4 },
-  { "FIFTH",   tUNUMBER,        5 },
-  { "SIXTH",   tUNUMBER,        6 },
-  { "SEVENTH", tUNUMBER,        7 },
-  { "EIGHTH",  tUNUMBER,        8 },
-  { "NINTH",   tUNUMBER,        9 },
-  { "TENTH",   tUNUMBER,       10 },
-  { "ELEVENTH",        tUNUMBER,       11 },
-  { "TWELFTH", tUNUMBER,       12 },
+  { "LAST",    tORDINAL,       -1 },
+  { "THIS",    tORDINAL,        0 },
+  { "NEXT",    tORDINAL,        1 },
+  { "FIRST",   tORDINAL,        1 },
+/*{ "SECOND",  tORDINAL,        2 }, */
+  { "THIRD",   tORDINAL,        3 },
+  { "FOURTH",  tORDINAL,        4 },
+  { "FIFTH",   tORDINAL,        5 },
+  { "SIXTH",   tORDINAL,        6 },
+  { "SEVENTH", tORDINAL,        7 },
+  { "EIGHTH",  tORDINAL,        8 },
+  { "NINTH",   tORDINAL,        9 },
+  { "TENTH",   tORDINAL,       10 },
+  { "ELEVENTH",        tORDINAL,       11 },
+  { "TWELFTH", tORDINAL,       12 },
   { "AGO",     tAGO,            1 },
   { NULL, 0, 0 }
 };