Re: Bignumber conversion and arithmetic on unsigned operand pairs using +,-,* now work in anybase.

From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Newsgroups	comp.lang.javascript
Subject	Re: Bignumber conversion and arithmetic on unsigned operand pairs using +,-,* now work in anybase.
Date	2015-06-23 23:37 +0200
Organization	PointedEars Software (PES)
Message-ID	<1447875.8cPT3z67Bs@PointedEars.de> (permalink)
References	(5 earlier) <87a8vskcyp.fsf@bsb.me.uk> <4723ff16-0052-41e3-8d3a-6c249345696e@googlegroups.com> <87twu0iogk.fsf@bsb.me.uk> <3774f4ba-032f-4ecb-8542-355beb009200@googlegroups.com> <871th3ikr0.fsf@bsb.me.uk>

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Ben Bacarisse wrote:

> jonas.thornvall@gmail.com writes:
>> why do you think there is no
>> other javascript or program on the net that can transform a 100 digit
>> number into an 8 digit base.
> 
> https://github.com/silentmatt/javascript-biginteger/blob/master/biginteger.js
> 
> It does not do exactly what you asked for, but the reasons why it does
> not do that are worth considering.

It certainly leaves room for improvement.  For example,

  BigInteger.small = [
	ZERO,
	ONE,
	/* Assuming BigInteger_base > 36 */
	new BigInteger( [2], 1, CONSTRUCT),
	new BigInteger( [3], 1, CONSTRUCT),
	new BigInteger( [4], 1, CONSTRUCT),
	new BigInteger( [5], 1, CONSTRUCT),
	new BigInteger( [6], 1, CONSTRUCT),
	new BigInteger( [7], 1, CONSTRUCT),
	new BigInteger( [8], 1, CONSTRUCT),
	new BigInteger( [9], 1, CONSTRUCT),
	new BigInteger([10], 1, CONSTRUCT),
	new BigInteger([11], 1, CONSTRUCT),
	new BigInteger([12], 1, CONSTRUCT),
	new BigInteger([13], 1, CONSTRUCT),
	new BigInteger([14], 1, CONSTRUCT),
	new BigInteger([15], 1, CONSTRUCT),
	new BigInteger([16], 1, CONSTRUCT),
	new BigInteger([17], 1, CONSTRUCT),
	new BigInteger([18], 1, CONSTRUCT),
	new BigInteger([19], 1, CONSTRUCT),
	new BigInteger([20], 1, CONSTRUCT),
	new BigInteger([21], 1, CONSTRUCT),
	new BigInteger([22], 1, CONSTRUCT),
	new BigInteger([23], 1, CONSTRUCT),
	new BigInteger([24], 1, CONSTRUCT),
	new BigInteger([25], 1, CONSTRUCT),
	new BigInteger([26], 1, CONSTRUCT),
	new BigInteger([27], 1, CONSTRUCT),
	new BigInteger([28], 1, CONSTRUCT),
	new BigInteger([29], 1, CONSTRUCT),
	new BigInteger([30], 1, CONSTRUCT),
	new BigInteger([31], 1, CONSTRUCT),
	new BigInteger([32], 1, CONSTRUCT),
	new BigInteger([33], 1, CONSTRUCT),
	new BigInteger([34], 1, CONSTRUCT),
	new BigInteger([35], 1, CONSTRUCT),
	new BigInteger([36], 1, CONSTRUCT)
  ];

can be written in a DRY way as

  BigInteger.small = Array.apply(null, {length: 37}).map(function (e, i) {
    return {
      0: ZERO,
      1: ONE,
    }[i] || new BigInteger([i], 1, CONSTRUCT);
  });

whereas only Array.prototype.map() would need to be emulated in a conforming 
implementation of ECMAScript Edition 3.  [Assuming that both ZERO and ONE 
are not false-values.  Here we can see the value of a constructor being 
callable as a function, assuming that something like JSX’s 
Function.prototype.construct() is not available; unfortunately, ES6/2015 
still is not going to have something like this as a built-in.]

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