cron

A fast non-allocating cron parser in ragel and golang.

features

• standard five-position cron
• six-position cron with seconds
• seven-position cron with seconds and years
• case-insensitive days of the week
• case-insensitive month names
• Quartz compatible ranges e.g.: 4/10, SUN-THURS/2
• timezone handling (other than UTC)
• Quartz compatible # handling, i.e. 5#3 meaning the third friday of the month
• Quartz compatible L handling, i.e. 5L in the day of week field meaning the last friday of a month, or 3L in the day of month field meaning third to last day of the month

performance

On a 3.1 Ghz Core i7 MacBook Pro (Retina, 15-inch, Mid 2017):

BenchmarkParse/0_*_*_*_*_*_*-8	20000000	63.5 ns/op	0 B/op
BenchmarkParse/1-6/2_*_*_*_Feb-Oct/3_*_*-8	10000000	118 ns/op	0 B/op
BenchmarkParse/1-6/2_*_*_*_Feb-Oct/3_*_2020/4-8	1000000	146 ns/op	0 B/op

TODO

• Once we are done adding all of the Quartz cron features, to copy and pass all of Quartz's parsing tests.