A natural language date and time parser for Common Lisp.
Inspired by (and copied verbatim from) from Chronic, the natural language date and time parser for Ruby by Tom Preston-Werner.
To understand how Chronicity works, read this post: Writing a natural language date and time parser
Use quicklisp:
(ql:quickload "chronicity")
Or get the cutting-edge version from github: https://github.com/chaitanyagupta/chronicity/tree/master
Or get the latest stable release (usually updates before quicklisp): https://github.com/chaitanyagupta/chronicity/releases
Use CHRONICITY:PARSE to parse date/time strings.
If *NOW* is not set, "now" is assumed to be this instant. All relative
date/time calculations are made with respect to *NOW*.
(setf chronicity:*now* (chronicity:make-datetime 2009 3 27 12 34 56))
=> @2009-03-27T12:34:56.000000+05:30
(chronicity:parse "today")
=> @2009-03-27T13:00:00.000000+05:30
(chronicity:parse "tomorrow" :now (chronicity:make-date 2009 1 1))
=> @2009-01-02T00:00:00.000000+05:30
(chronicity:parse "3 days from now")
=> @2009-03-30T12:34:56.000000+05:30
(chronicity:parse "next month")
=> @2009-04-01T00:00:00.000000+05:30
:ENDIAN-PREFERENCE indicates which date format to prefer in case of
ambiguity over days and months. :LITTLE indicates the format
"dd/mm/yyyy", :MIDDLE indicates "mm/dd/yyy". Default is :LITTLE.
(chronicity:parse "1/2/2003")
=> @2003-02-01T00:00:00.000000+05:30
(chronicity:parse "1/2/2003" :endian-preference :middle)
=> @2003-01-02T00:00:00.000000+05:30
Default value for :CONTEXT is :FUTURE.
(chronicity:parse "April 1st at 12:30 PM")
=> @2009-04-01T12:30:00.000000+05:30
(chronicity:parse "April 1st at 12:30 PM" :context :past)
=> @2008-04-01T12:30:00.000000+05:30
CHRONICITY:PARSE usually returns a DATETIME object. Its attributes can
be accessed using the datetime readers.
(chronicity:parse "next month" :guess :end)
=> @2009-04-30T23:59:59.000000+05:30
(values (chronicity:year-of *)
(chronicity:month-of *)
(chronicity:day-of *)
(chronicity:hour-of *)
(chronicity:minute-of *)
(chronicity:sec-of *))
=> 2009, 4, 30, 23, 59, 59
Passing NIL as the value for :GUESS returns a SPAN, which is a range
of datetime values.
(chronicity:parse "next month" :guess nil)
=> #<CHRONICITY::SPAN 2009-04-01T00:00:00.000000+05:30...2009-05-01T00:00:00.000000+05:30>
(values (chronicity:span-start *)
(chronicity:span-end *)
(chronicity:span-end-included-p *))
=> @2009-04-01T00:00:00.000000+05:30,
@2009-05-01T00:00:00.000000+05:30,
NIL
Other possible values are :START, :MIDDLE, or :END which return
the start, mid-point or the end of a span respectively.
Simple
thursday
november
summer
friday 13:00
mon 2:35
4pm
6 in the morning
friday 1pm
sat 7 in the evening
yesterday
today
tomorrow
this tuesday
next month
this morning
last night
this second
yesterday at 4:00
last friday at 20:00
last week tuesday
tomorrow at 6:45pm
afternoon yesterday
thursday last week
Complex
3 years ago
5 months before now
7 hours ago
7 days from now
1 week hence
in 3 hours
1 year ago tomorrow
3 months ago saturday at 5:00 pm
7 hours before tomorrow at noon
3rd wednesday in november
3rd month next year
3rd thursday this september
4th day last week
Specific Dates
January 5
dec 25
may 27th
October 2006
oct 06
jan 3 2010
february 14, 2004
3 jan 2000
17 april 85
5/27/1979
27/5/1979
05/06
1979-05-27
Friday
5
4:00
17:00
0800
Specific Times (many of the above with an added time)
January 5 at 7pm
1979-05-27 05:00:00
etc
Chronicity only works with the current timezone (as returned by
LOCAL-TIME:*DEFAULT-TIMEZONE*) . Support for different timezones is
planned for a future release.
The datetime object(s) returned by the parser are of type
LOCAL-TIME:TIMESTAMP. Be aware of any limitations that may apply to
them.
Another problem is that parsing ordinals as words is supported except
for second, which is ambiguous with second the unit of time. This
should be fixed in a future release.