Upstream spencermountain/compromise state of the touched files before ce85479ef4

plugins/dates/src/api/parse/one/01-tokenize/01-shift.js

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+const knownUnits = {
+  second: true,
+  minute: true,
+  hour: true,
+  day: true,
+  week: true,
+  weekend: true,
+  month: true,
+  season: true,
+  quarter: true,
+  year: true,
+}
+
+const aliases = {
+  wk: 'week',
+  min: 'minute',
+  sec: 'second',
+  weekend: 'week', //for now...
+}
+
+// half of a unit, in smaller whole units
+const halfUnits = {
+  year: [6, 'month'],
+  quarter: [45, 'day'],
+  season: [45, 'day'],
+  month: [15, 'day'],
+  week: [84, 'hour'],
+  day: [12, 'hour'],
+  hour: [30, 'minute'],
+  minute: [30, 'second'],
+}
+
+const parseUnit = function (m) {
+  let unit = m.match('#Duration').text('normal')
+  unit = unit.replace(/s$/, '')
+  // support shorthands like 'min'
+  if (Object.hasOwn(aliases, unit)) {
+    unit = aliases[unit]
+  }
+  return unit
+}
+
+//turn '5 weeks before' to {weeks:5}
+const parseShift = function (doc) {
+  const result = {}
+  let m = doc.none()
+  let shift = doc.match('#DateShift+')
+  if (shift.found === false) {
+    return { result, m }
+  }
+  //is it 2 weeks ago?  → -2  ('hence' means the future)
+  const isNegative = shift.has('(before|ago|back)$') === true
+
+  // '5 weeks'
+  shift.match('#Cardinal #Duration').forEach((ts) => {
+    const num = ts.match('#Cardinal').numbers().get()[0]
+    if (num && typeof num === 'number') {
+      const unit = parseUnit(ts)
+      if (knownUnits[unit] === true) {
+        result[unit] = isNegative ? num * -1 : num
+      }
+    }
+  })
+  m = shift.match('#Cardinal #Duration')
+  shift = shift.not(m)
+
+  // supoprt '1 day after tomorrow'
+  m = shift.match('[<unit>#Duration] [<dir>(after|before)]')
+  if (m.found) {
+    const unit = m.groups('unit').text('reduced')
+    // unit = unit.replace(/s$/, '')
+    const dir = m.groups('dir').text('reduced')
+    if (dir === 'after') {
+      result[unit] = 1
+    } else if (dir === 'before') {
+      result[unit] = -1
+    }
+  }
+
+  // in half an hour
+  m = shift.match('half (a|an) [#Duration]', 0)
+  if (m.found) {
+    const unit = parseUnit(m)
+    if (knownUnits[unit] === true) {
+      result[unit] = isNegative ? -0.5 : 0.5
+    }
+  }
+
+  // a few years / a couple of weeks
+  m = shift.match('a [<amt>(few|couple)] of? [<unit>#Duration]')
+  if (m.found) {
+    const unit = parseUnit(m.groups('unit'))
+    if (knownUnits[unit] === true) {
+      const num = m.groups('amt').has('few') ? 3 : 2
+      result[unit] = isNegative ? num * -1 : num
+    }
+  }
+
+  // '2 weeks and a half'
+  m = doc.match('[<unit>#Duration] and a half')
+  if (m.found) {
+    const unit = parseUnit(m.groups('unit'))
+    if (knownUnits[unit] === true && result[unit] !== undefined) {
+      result[unit] += isNegative ? -0.5 : 0.5
+    }
+  }
+
+  // spacetime drops fractional units - swap a half-unit for smaller whole units
+  Object.keys(result).forEach((k) => {
+    const whole = Math.trunc(result[k])
+    const frac = result[k] - whole
+    if (frac === 0.5 || frac === -0.5) {
+      const [num, smaller] = halfUnits[k] || []
+      if (smaller) {
+        result[k] = whole
+        result[smaller] = (result[smaller] || 0) + (frac > 0 ? num : num * -1)
+        if (result[k] === 0) {
+          delete result[k]
+        }
+      }
+    }
+  })
+
+  // finally, remove it from our text
+  m = doc.match('#DateShift+')
+  return { result, m }
+}
+export default parseShift