Date Fns Lost

Lost tools for moment including domain specific language for time manipulations and schedule operations.

import momentRange from 'moment-range'
import momentTz from 'moment-timezone'
const moment = momentRange.extendMoment(momentTz)
import lost from 'date-fns-lost'
const {
  chrono,
  spanner,
  schedule,
  dsl,
  iso8601
} = lost(moment)

const content = `
  //
  // A date constant is either an iso8601 string or a reference
  // to another constant. Constants can optionally be followed
  // immediately by spanner operations.
  //
  // day_in_june: 2018-06-15T10:00:00Z
  // start_of_june: day_in_june/M
  //
  //
  // An interval is a repeating pattern and can be specified as:
  //
  // interval(anchor, duration, repeat)
  //
  // Where:
  //   anchor   - A reference to a constant optionally followed
  //              by spanner operations.
  //   duration - A spanner operation to calculate the duration
  //              of each iteration.
  //   repeat   - A number followed by the name or short code
  //              of a unit to jump forward and backwards from
  //              anchor to create the pattern.
  //
  //
  // A range is all time between a start and an end
  //
  // range(start, end)
  //
  // Where:
  //   start    - A reference to a constant optionally followed
  //              by spanner operations. Inclusive in the range.
  //   end      - A reference to a constant optionally followed
  //              by spanner operations. Inclusive in the range.
  //
  //
  // Both interval and range cannot accept iso8601 parameters,
  // these can be defined as constants and referenced.
  //
  //
  // Spanner operations are executed sequentially against a
  // constant or if not supplied will default to the current time.
  //
  // (timezone) - Changes all following operations to be
  //              executed in the supplied timezone.
  //              http://momentjs.com/timezone/
  // +5days     - Add or substract a multiple of a time unit.
  // +5d4h      - Can use short codes and multiple units.
  // /M         - Jump to the start of time unit.
  //

  start: now/M
  end: now+4M/M

  result:
  + interval(now/M, +7d, 1M)
  * interval(/isoWeek+1d, +1d, 1w)

`
const parsed = dsl.parse(content)
console.log(parsed.schedules)
const clip = moment.range(parsed.constants.start, parsed.constants.end)
const segments = schedule.between(parsed.schedules, parsed.schedules.result, clip)
for (let segment of segments)
  console.log(segment.start.format(iso8601), '—', segment.end.format(iso8601))