when 
whenis a natural language date/time parser with pluggable rules and merge strategies
Examples
- tonight at 11:10 pm
- at Friday afternoon
- the deadline is next tuesday 14:00
- drop me a line in next wednesday at 2:25 p.m
- it could be done at 11 am past tuesday
Check EN and RU rules and tests for them, for more examples.
How it works
Usually, there are several rules added to the parser's instance for checking. Each rule has own borders - length and offset in provided string. Meanwhile, each rule yields only the first match over the string. So, the library is checking all the rules and extracting a cluster of matched rules which have distance between each other less or equal options.Distance, 5 by default. For example:
in next wednesday at 2:25 p.m.
└──────┬─────┘ └───┬───┘
weekday hour + minute
So, we have a cluster of matched rules - "next wednesday at 2:25 p.m." in the string representation.
After that, each rule is being applied to the context. In order of definition or in match order, if options.MatchByOrder set in true(by default). Each rule could be applied with given merge strategy. By default, it's an Override strategy. The other strategies are not implemented yet in the rules. Pull requests are welcome any time.
Usage
w := when.New(nil)
w.Add(en.All...)
w.Add(common.All...)
text := "drop me a line in next wednesday at 2:25 p.m"
r, err := w.Parse(text, time.Now())
if err != nil {
// an error has occurred
}
if r == nil {
// no matches found
}
fmt.Println(
"the time",
r.Time.String(),
"mentioned in",
text[r.Index:len(r.Text)],
)State of the project
The project is in a more-or-less complete state. It used for one project already. Bugs will be fixed as soon as they will be found.