Parse 'a dozen' and 'two dozen' as numbers

src/2-two/postTagger/model/numbers/numbers.js

@@ -37,6 +37,15 @@ export default [
     tag: 'Value',
     reason: 'a-trillion',
   },
+  // two [dozen] eggs
+  { match: '(a|#Cardinal) [dozen]', hook: 'dozen', group: 0, tag: ['Multiple', 'Cardinal'], reason: 'value-dozen' },
+  // with [a] dozen eggs
+  {
+    match: '!once? [a] dozen', hook: 'dozen',
+    group: 0,
+    tag: 'Value',
+    reason: 'a-dozen',
+  },
   // ==== PhoneNumber ====
   // 1 800 555-1234
   { match: '(1|+1) #Value #PhoneNumber', tag: 'PhoneNumber', reason: 'country-code' },

src/3-three/numbers/numbers/parse/toNumber/data.js

@@ -83,5 +83,6 @@ export default {
     sextillion: 1e21,
     septillion: 1e24,
     grand: 1000,
+    dozen: 12,
   },
 }

tests/three/numbers/number-parse.test.js

@@ -45,3 +45,18 @@ test('parse numbers', function (t) {
   })
   t.end()
 })
+
+test('parse dozen', function (t) {
+  const arr = [
+    ['a dozen', 12],
+    ['two dozen eggs', 24],
+    ['three dozen', 36],
+    ['i bought a dozen eggs', 12],
+    ['half a dozen eggs', 6],
+  ]
+  arr.forEach(function (a) {
+    const num = nlp(a[0]).numbers().get()[0]
+    t.equal(num, a[1], here + a[0])
+  })
+  t.end()
+})