common: implement longCountJDN function

Author: quantum5

common/src/longCount.test.ts

@@ -1,4 +1,4 @@
-import {jdnLongCount} from './longCount';
+import {jdnLongCount, longCountJDN} from './longCount';
 
 describe('jdnLongCount', () => {
     it('works for normal dates', () => {
@@ -59,4 +59,60 @@ describe('jdnLongCount', () => {
         expect(jdnLongCount(0)).toBeNull();
         expect(jdnLongCount(584282)).toBeNull();
     });
-})
+});
+
+describe('longCountJDN', () => {
+    it('works for normal dates', () => {
+        expect(longCountJDN([12, 19, 19, 17, 19])).toEqual(2456282);
+        expect(longCountJDN([13, 0, 8, 12, 10])).toEqual(2459413);
+        expect(longCountJDN([7, 16, 3, 2, 13])).toEqual(1708616);
+        expect(longCountJDN([8, 7, 3, 2, 13])).toEqual(1787816);
+        expect(longCountJDN([7, 16, 6, 16, 18])).toEqual(1709981);
+        expect(longCountJDN([7, 18, 9, 7, 12])).toEqual(1725275);
+        expect(longCountJDN([7, 18, 14, 8, 12])).toEqual(1727095);
+        expect(longCountJDN([7, 19, 7, 8, 12])).toEqual(1731775);
+        expect(longCountJDN([7, 19, 15, 7, 12])).toEqual(1734635);
+        expect(longCountJDN([8, 2, 2, 10, 15])).toEqual(1751618);
+        expect(longCountJDN([8, 3, 2, 10, 15])).toEqual(1758818);
+        expect(longCountJDN([8, 4, 5, 17, 11])).toEqual(1767234);
+        expect(longCountJDN([8, 5, 3, 3, 5])).toEqual(1773428);
+        expect(longCountJDN([8, 5, 16, 9, 7])).toEqual(1778230);
+        expect(longCountJDN([8, 6, 2, 4, 17])).toEqual(1780300);
+        expect(longCountJDN([11, 16, 0, 0, 0])).toEqual(2283483);
+        expect(longCountJDN([0, 0, 0, 0, 0])).toEqual(584283);
+        expect(longCountJDN([1, 0, 0, 0, 0])).toEqual(728283);
+        expect(longCountJDN([2, 0, 0, 0, 0])).toEqual(872283);
+        expect(longCountJDN([3, 0, 0, 0, 0])).toEqual(1016283);
+        expect(longCountJDN([4, 0, 0, 0, 0])).toEqual(1160283);
+        expect(longCountJDN([5, 0, 0, 0, 0])).toEqual(1304283);
+        expect(longCountJDN([6, 0, 0, 0, 0])).toEqual(1448283);
+        expect(longCountJDN([7, 0, 0, 0, 0])).toEqual(1592283);
+        expect(longCountJDN([8, 0, 0, 0, 0])).toEqual(1736283);
+        expect(longCountJDN([9, 0, 0, 0, 0])).toEqual(1880283);
+        expect(longCountJDN([10, 0, 0, 0, 0])).toEqual(2024283);
+        expect(longCountJDN([11, 0, 0, 0, 0])).toEqual(2168283);
+        expect(longCountJDN([12, 0, 0, 0, 0])).toEqual(2312283);
+        expect(longCountJDN([13, 0, 0, 0, 0])).toEqual(2456283);
+        expect(longCountJDN([14, 0, 0, 0, 0])).toEqual(2600283);
+        expect(longCountJDN([15, 0, 0, 0, 0])).toEqual(2744283);
+        expect(longCountJDN([16, 0, 0, 0, 0])).toEqual(2888283);
+        expect(longCountJDN([17, 0, 0, 0, 0])).toEqual(3032283);
+        expect(longCountJDN([18, 0, 0, 0, 0])).toEqual(3176283);
+        expect(longCountJDN([19, 0, 0, 0, 0])).toEqual(3320283);
+        expect(longCountJDN([1, 0, 0, 0, 0, 0])).toEqual(3464283);
+        expect(longCountJDN([9, 8, 9, 13, 0])).toEqual(1941383);
+    });
+
+    it('works for insane dates in the future', () => {
+        expect(longCountJDN([1, 5, 13, 5, 5, 4, 0, 11, 13, 13])).toEqual(591279564516);
+        expect(longCountJDN([1, 4, 15, 12, 19, 13, 13, 3, 8, 15])).toEqual(570988471138);
+        expect(longCountJDN([7, 4, 9, 1, 6, 3, 13, 14, 18])).toEqual(166410754861);
+        expect(longCountJDN([7, 13, 6, 10, 7, 1, 19, 4, 16])).toEqual(176632006419);
+        expect(longCountJDN([1, 8, 6, 9, 2, 3, 17, 16, 10, 2])).toEqual(652557304645);
+        expect(longCountJDN([6, 1, 15, 16, 19, 2, 7, 1, 19])).toEqual(140305417242);
+        expect(longCountJDN([1, 14, 19, 11, 2, 0, 8, 0, 8, 15])).toEqual(805888002058);
+        expect(longCountJDN([7, 13, 3, 1, 11, 5, 16, 7, 19])).toEqual(176433890202);
+        expect(longCountJDN([14, 8, 1, 18, 17, 10, 5, 13, 18])).toEqual(331888546361);
+        expect(longCountJDN([1, 8, 10, 12, 11, 2, 1, 14, 0, 13])).toEqual(657363764536);
+    });
+});

common/src/longCount.ts

@@ -18,3 +18,11 @@ export function jdnLongCount(jdn: number): LongCount | null {
 
     return parts.reverse();
 }
+
+export function longCountJDN(longCount: LongCount): number {
+    const state = [...longCount];
+    const last = (state.pop() ?? 0) + (state.pop() ?? 0) * 20;
+    let sum = 0;
+    state.forEach((value) => sum = sum * 20 + value);
+    return sum * 360 + last + 584283;
+}