urbit-ob

commit 10abf765b782549d01822dddd7f6e22a82489115
parent f3ce19a94bfd03afd372d271d24bf28bbbb8f5cf
Author: Jared Tobin <jared@jtobin.io>
Date:   Fri,  5 Oct 2018 15:27:50 +1300

Merge pull request #6 from urbit/jt-add-sein

Add's Hoon's "sein" function
Diffstat:
M
src/index.js
 | 
56
++++++++++++++++++++++++++++++++++++++++++--------------
M
test/core.test.js
 | 
30
++++++++++++++++++++++++++----

2 files changed, 68 insertions(+), 18 deletions(-)
diff --git a/src/index.js b/src/index.js
@@ -293,27 +293,55 @@ const murmur3 = (data, seed) => {
  *
  */
 
-const bex = (n) => {
-  const two = new bnjs(2)
-  return two.pow(n)
+const zero = new bnjs(0)
+const one = new bnjs(1)
+const two = new bnjs(2)
+const three = new bnjs(3)
+const four = new bnjs(4)
+const five = new bnjs(5)
+
+const clan = (who) => {
+  const wid = met(three, who)
+  return wid.lte(one)
+    ? 'czar'
+    : wid.eq(two)
+    ? 'king'
+    : wid.lte(four)
+    ? 'duke'
+    : wid.lte(new bnjs(8))
+    ? 'earl'
+    : 'pawn'
 }
 
+const sein = (who) => {
+  const mir = clan(who)
+  const res =
+    mir === 'czar'
+    ? who
+    : mir === 'king'
+    ? end(three, one, who)
+    : mir === 'duke'
+    ? end(four, one, who)
+    : mir === 'earl'
+    ? end(five, one, who)
+    : zero
+  return add2patp(res)
+}
+
+const bex = (n) => two.pow(n)
+
 const rsh = (a, b, c) => {
   const sub = bex(a).mul(b)
   return c.div(bex(sub))
 }
 
-const met = (a, b, c = new bnjs(0)) => {
-  const zero = new bnjs(0)
-  const one = new bnjs(1)
+const met = (a, b, c = zero) => {
   return b.eq(zero)
     ? c
     : met(a, rsh(a, one, b), c.add(one))
 }
 
-const end = (a, b, c) => {
-  return c.mod(bex(bex(a).mul(b)))
-}
+const end = (a, b, c) => c.mod(bex(bex(a).mul(b)))
 
 const lsh = (a, b, c) => {
   const sub = bex(a).mul(b)
@@ -322,11 +350,6 @@ const lsh = (a, b, c) => {
 
 // bignum patp
 const patp = (n) => {
-  const zero = new bnjs(0)
-  const one = new bnjs(1)
-  const three = new bnjs(3)
-  const four = new bnjs(4)
-
   let sxz = new bnjs(feen(n))
   let dyy = met(four, sxz)
 
@@ -501,6 +524,9 @@ module.exports = {
 
   patp: patp,
 
+  sein: sein,
+  _clan: clan,
+
   _add2patp: _add2patp,
   _getsuffix: getSuffix,
   _muk: muk,
@@ -525,5 +551,7 @@ module.exports = {
   _dec2bin: dec2bin,
   _syl2bin: syl2bin,
 
+  _met: met,
+
   _arr2patp: arr2patp
 }
diff --git a/test/core.test.js b/test/core.test.js
@@ -110,23 +110,45 @@ test('identifies poldec-tonteg as a planet from address', () => {
   expect(ob.tierOfadd(9896704)).toBe('planet');
 });
 
-test('correctly encodes 0 as @p', () => {
+test('patp correctly encodes 0 as @p', () => {
   let expected = '~zod';
   expect(ob.patp('0')).toBe(expected);
 });
 
-test('correctly encodes 4294967295 as @p', () => {
+test('patp correctly encodes 4294967295 as @p', () => {
   let expected = '~dostec-risfen';
   expect(ob.patp('4294967295')).toBe(expected);
 });
 
-test('correctly encodes 328256967394537077627 as @p', () => {
+test('patp correctly encodes 328256967394537077627 as @p', () => {
   let expected = '~dozsyx--halrux-samlep-posmus-ranrux';
   expect(ob.patp('328256967394537077627')).toBe(expected);
 });
 
-test('correctly encodes a big hex string as @p', () => {
+test('patp correctly encodes a big hex string as @p', () => {
   let input = new bnjs('7468697320697320736f6d6520766572792068696768207175616c69747920656e74726f7079', 16);
   let expected = '~divmes-davset-holdet--sallun-salpel-taswet-holtex--watmeb-tarlun-picdet-magmes--holter-dacruc-timdet-divtud--holwet-maldut-padpel-sivtud';
   expect(ob.patp(input)).toBe(expected);
 });
+
+test('clan works as expected', () => {
+  expect(ob._clan(new bnjs(0))).toBe('czar');
+  expect(ob._clan(new bnjs(255))).toBe('czar');
+  expect(ob._clan(new bnjs(256))).toBe('king');
+  expect(ob._clan(new bnjs(50000))).toBe('king');
+  expect(ob._clan(new bnjs(70000))).toBe('duke');
+  expect(ob._clan(new bnjs(2170000))).toBe('duke');
+  expect(ob._clan(new bnjs('5232170000'))).toBe('earl');
+  expect(ob._clan(new bnjs('525525525125232170000'))).toBe('pawn');
+})
+
+test('sein identifies parents correctly', () => {
+  expect(ob.sein(new bnjs(0))).toBe('zod');
+  expect(ob.sein(new bnjs(1))).toBe('nec');
+  expect(ob.sein(new bnjs(250))).toBe('rep');
+  expect(ob.sein(new bnjs(256))).toBe('zod');
+  expect(ob.sein(new bnjs(257))).toBe('nec');
+  expect(ob.sein(new bnjs(50000))).toBe('sec');
+  expect(ob.sein(new bnjs(15663360))).toBe('marzod');
+  expect(ob.sein(new bnjs(15663361))).toBe('marnec');
+});