https://github.com/henryw374/time-literals.git
git clone 'https://github.com/henryw374/time-literals.git'
(ql:quickload :henryw374.time-literals)
A Clojure(Script) library which provides tagged literals for objects from jsr-310 domain,
which on the jvm is objects from the java.time library and in Javascript is a
‘jsr-310 clone’ library (yes, it is actually an implementation of JSR-310,
rather than joda-time, as it's name would suggest).
This enables copying and pasting these objects within the REPL, conveying these objects across process boundaries & etc.
My talk at Clojure/North 2019 provides some more background.
cljc.java-time is a one for one mapping of the classes and methods from java.time into a Clojure(Script) library
The tick library is an intuitive Clojure(Script) library for dealing with time, intended as a replacement for clj-time. It bundles this library and enables time-literals printing
by default.
Lein/Boot
The library includes the magic file data_readers.cljc which Clojure and the Clojurescript
compilers() will look for.
In order to modify the printer to print these literals, run:
(time-literals.read-write/print-time-literals-clj!)
(time-literals.read-write/print-time-literals-cljs!)
Example literals:
#time/month "JUNE"
#time/period "P1D"
#time/date "2039-01-01"
#time/date-time "2018-07-25T08:08:44.026"
#time/zoned-date-time "2018-07-25T08:09:11.227+01:00[Europe/London]"
#time/offset-date-time "2018-07-25T08:11:54.453+01:00"
#time/instant "2018-07-25T07:10:05.861Z"
#time/time "08:12:13.366"
#time/duration "PT1S"
#time/year "3030"
#time/year-month "3030-01"
#time/zone "Europe/London"
#time/day-of-week "TUESDAY"For example, in a Clojure repl:
(require 'time-literals.data-readers)
; Get a node repl going, or equivalent start figwheel and connect with sidecar etc
(require '[cljs.repl :as cljs-repl])
(require '[cljs.repl.node :as node])
(cljs-repl/repl* (node/repl-env)
{:output-dir "out"
:optimizations :none
:cache-analysis true
:source-map true})
;Now, in cljs repl
(require '[java.time])
(println #time/duration "PT1S")
; => #object[Duration PT1S]
; Now, include printing and edn reading
(require '[time-literals.read-write])
(time-literals.read-write/print-time-literals-cljs!)
(println #time/duration "PT1S")
; => #time/duration "PT1S"
Read an edn string:
(cljs.reader/read-string "#time/date \"2011-01-01\"")
TODO
As with any non-core tagged literal, the tag reader functions referred to from a data_readers file must be loaded before the forms can be read.
(require '[time-literals.data-readers]) ;; For literals
(require '[time-literals.read-write]) ;; For printing/writing
(time-literals.read-write/print-time-literals-clj!)
(println #time/duration "PT1S")
(require '[time-literals.read-write])
(time-literals.read-write/print-time-literals-clj!)
Printing will now automatically change, for example re run the println above
Read edn like this:
(clojure.edn/read-string {:readers time-literals.read-write/tags} "#time/date \"2011-01-01\"")Using clojure.core/read-string, you'd need to eval after the call to read-string
If you only need Instant from java.time/jsr-310, you could just rebind the tag readers and printer fns for #inst
There is a similar library, java-time-literals but this currently only works
on the jvm, and also doesn't provide a way to read edn with the literals (via clojure.edn/read-string or cljs.reader). The naming of tags
in this library (time-literals) follows the tick convention, for example
#time/date for LocalDate, instead of #time/ld as in java-time-literals.
TL;DR it is sufficiently ambiguous.
This library reads/writes java.time objects. It would be feasible to use the same set of tags with a different time library, either on the jvm or other elsewhere. If the namespace were ‘jsr310’ or ‘java.time’ that would be too implementaion specific.
A set of literals for the ISO-8601 specification would probably be the ideal for date interchange, with literals such as `#iso8601/ordinal-date“1981-095”``
However, although the Java.time domain overlaps significantly with concepts in ISO-8601, there are differences. For example, the ISO ‘Duration’ is roughly a combination of java.time.Duration and java.time.Period, and the IANA time zone names (such are you see in the literal representation of ZonedDateTime) are not part of ISO.
Copyright © 2019 Widd Industries
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.