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Jonas Raoni Soares Silva http://www.jsfromhell.com

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BigNumber //JavaScript Class


Offers a extremely high precision level to make mathematical operations. For integers there is no limits and for floating point numbers, the class allows setting the maximum precision.

[UPDATED CODE AND HELP CAN BE FOUND HERE]

The class always returns new instances of BigNumber on the operations, so to the set value of a object, use the "set" method.


//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/classes/bignumber [v1.0]

BigNumber = function(n, p, r){
    var o = this, i;
    if(n instanceof BigNumber){
        for(i in {precision: 0, roundType: 0, _sign: 0, _dec: 0}) o[i] = n[i];
        o._buffer = n._buffer.slice();
        return;
    }
    o.precision = isNaN(p = Math.abs(p)) ? BigNumber.defaultPrecision : p;
    o.roundType = isNaN(r = Math.abs(r)) ? BigNumber.defaultRoundType : r;
    o._sign = (n += "").charAt(0) == "-";
    o._dec = ((n = n.replace(/[^\d.]/g, "").split(".", 2))[0] = n[0].replace(/^0+/, "") || "0").length;
    for(i = (n = o._buffer = (n.join("") || "0").split("")).length; i; n[--i] = +n[i]);
    o.round();
};
with({$: BigNumber, o: BigNumber.prototype}){
    $.ROUND_HALF_EVEN = ($.ROUND_HALF_DOWN = ($.ROUND_HALF_UP = ($.ROUND_FLOOR = ($.ROUND_CEIL = ($.ROUND_DOWN = ($.ROUND_UP = 0) + 1) + 1) + 1) + 1) + 1) + 1;
    $.defaultPrecision = 40;
    $.defaultRoundType = $.ROUND_HALF_UP;
    o.add = function(n){
        if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.subtract(n);
        var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = o._dec,
        lb = n._dec, n = Math.max(la, lb), i, r;
        la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1));
        i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length;
        for(r = 0; i; r = (a[--i] = a[i] + b[i] + r) / 10 >>> 0, a[i] %= 10);
        return r && ++n && a.unshift(r), o._dec = n, o.round();
    };
    o.subtract = function(n){
        if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.add(n);
        var o = new BigNumber(this), x = o.compare(n) + 1, a = x ? o : n, b = x ? n : o, la = a._dec, lb = b._dec, n = la, i, j;
        a = a._buffer, b = b._buffer, la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1));
        for(i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; i;){
            if(a[--i] < b[i]){
                for(j = i; j && !a[--j]; a[j] = 9);
                --a[j], a[i] += 10;
            }
            b[i] = a[i] - b[i];
        }
        return o._sign = !x, o._dec = n, o._buffer = b, o.round();
    };
    o.multiply = function(n){
        var o = new BigNumber(this), r = o.compare(n = new BigNumber(n)) + 1, a = (r ? o : n)._buffer,
        b = (r ? n : o)._buffer, la = a.length, lb = b.length, x = new BigNumber, i, j, s;
        for(i = lb; i; x.set(x.add(new BigNumber(s.join("")))))
            for(s = (new Array(lb - --i)).join("0").split(""), r = 0, j = la; j;
            r += a[--j] * b[i], s.unshift(r % 10), r = r / 10 >>> 0);
        return r && x._buffer.unshift(r), o._dec = (o._buffer = x._buffer).length - la - lb + o._dec + n._dec, o.round();
    };
    o.divide = function(n){
        if((n = new BigNumber(n)) == "0") throw new Error("division by 0");
        var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = a.length - o._dec,
        lb = b.length - n._dec, s = a._sign != b._sign, dec = 0, buffer = [], x = new BigNumber, y, i;
        la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb));
        o._dec = a.length, n._dec = b.length;
        b = n, a._sign = false, b._sign = false;
        while(o != 0 && (buffer.length - dec) <= o.precision){
            x.set(0);
            for(i = 0; o.compare(y = x.add(b)) + 1 && ++i; x.set(y));
            if(!i){
                do ++i, o._buffer.push(0), ++o._dec;
                while(o.compare(b) < 0);
                !dec && (!buffer.length && buffer.push(0), dec = buffer.length);
                o._zeroes(buffer, --i);
                continue;
            }
            o.set(o.subtract(x)), buffer.push(i);
        }
        return o._buffer = buffer, o._dec = dec ? dec : buffer.length, o.round();
    };
    o.mod = function(n){
        return this.subtract(this.divide(n).intPart().multiply(n));
    };
    o.pow = function(n){
        var o = new BigNumber(this), i;
        if(n == 0) return o.set(1);
        for(i = Math.abs(n); --i; o.set(o.multiply(this)));
        return n < 0 ? o.set((new BigNumber(1)).divide(o)) : o;
    };
    o.set = function(n){
        return this.constructor(n), this;
    };
    o.compare = function(n){
        var a = this, la = this._dec, b = n, lb = n._dec, i, l;
        if(la != lb) return la > lb ? 1 : -1;
        for(la = (a = a._buffer).length, lb = (b = b._buffer).length, i = -1, l = Math.min(la, lb); ++i < l;)
            if(a[i] != b[i]) return a[i] > b[i] ? 1 : -1;
        return la != lb ? la > lb ? 1 : -1 : 0;
    }
    o.negate = function(){
        var n = new BigNumber(this); return n._sign ^= 1, n;
    };
    o.abs = function(){
        var n = new BigNumber(this); return n._sign = 0, n;
    };
    o.intPart = function(){
        return new BigNumber((this._sign ? "-" : "") + (this._buffer.slice(0, this._dec).join("") || "0"));
    };
    o.valueOf = o.toString = function(){
        var o = this;
        return (o._sign ? "-" : "") + (o._buffer.slice(0, o._dec).join("") || "0") + (o._dec != o._buffer.length ? "." + o._buffer.slice(o._dec).join("") : "");
    };
    o._zeroes = function(n, l, t){
        var s = ["push", "unshift"][t || 0];
        for(++l; --l;  n[s](0));
        return n;
    };
    o.round = function(){
        if("_rounding" in this) return this;
        var $ = BigNumber, r = this.roundType, b = this._buffer, d, p, n, x;
        for(this._rounding = true; this._dec > 1 && !b[0]; --this._dec, b.shift());
        for(d = this._dec, p = this.precision + d, n = b[p]; b.length > d && !b[b.length -1]; b.pop());
        x = (this._sign ? "-" : "") + (p - d ? "0." + this._zeroes([], p - d - 1).join("") : "") + 1;
        if(b.length > p){
            n && (r == $.DOWN ? false : r == $.UP ? true : r == $.CEIL ? !this._sign
            : r == $.FLOOR ? this._sign : r == $.HALF_UP ? n >= 5 : r == $.HALF_DOWN ? n > 5
            : r == $.HALF_EVEN ? n >= 5 && b[p - 1] & 1 : false) && this.add(x);
            b.splice(p, b.length - p);
        }
        return delete this._rounding, this;
    };
}


Usage

<script type="text/javascript">

var x = new BigNumber("10"), y = new BigNumber("-2");
alert(x.pow(y));
alert(x.pow(1234));

alert((new BigNumber("99999999999999999999999999999999999")).add("999999999999999999999999999.99999999999999999"));

</script>
to javascript math integer number float jonas big high precision operation jsfromhell raoni by jonasraoni on Jun 15, 2006

Binary Data Parser //Javascript Class



This is a prototyped class written to serialize and unserialize binary data, so you can read and write binary data files to exchange with programs written in languages like C and Pascal.

Currently the class is able to handle just the following types: signed integers (small 8 bits, short 16 bits, int 32 bits), unsigned integers (byte 8 bits, word 16 bits, dword 32 bits) and floating point (IEEE754 float 32 bits and double 64 bits).

The endianess of the binary values representation can also be configured with the class.

[UPDATED CODE AND HELP CAN BE FOUND HERE]


There's a php version right here.

Code

//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/classes/binary-parser [v1.0]

BinaryParser = function( bigEndian, allowExceptions ){
	this.bigEndian = bigEndian;
	this.allowExceptions = allowExceptions;
};
with( { p: BinaryParser.prototype } ){
	with( {p: ( p.Buffer = function( bigEndian, buffer ){ this.bigEndian = bigEndian || 0; this.buffer = []; this.setBuffer( buffer ); } ).prototype } ){
		p.setBuffer = function( data ){
			if( data ){
				for( var l, i = l = data.length, b = this.buffer = new Array( l ); i; b[l - i] = data.charCodeAt( --i ) );
				this.bigEndian && b.reverse();
			}
		};
		p.hasNeededBits = function( neededBits ){
			return this.buffer.length >= -( -neededBits >> 3 );
		};
		p.checkBuffer = function( neededBits ){
			if( !this.hasNeededBits( neededBits ) )
				throw new Error( "checkBuffer::missing bytes" );
		};
		p.readBits = function( start, length ){
			//shl fix: Henri Torgemane ~1996 (compressed by Jonas Raoni)
			function shl( a, b ){
				for( ; b--; a = ( ( a %= 0x7fffffff + 1 ) & 0x40000000 ) == 0x40000000 ? a * 2 : ( a - 0x40000000 ) * 2 + 0x7fffffff + 1 );
				return a;
			}
			if( start < 0 || length <= 0 )
				return 0;
			this.checkBuffer( start + length );
			for( var offsetLeft, offsetRight = start % 8, curByte = this.buffer.length - ( start >> 3 ) - 1, lastByte = this.buffer.length + ( -( start + length ) >> 3 ), diff = curByte - lastByte, sum = ( ( this.buffer[ curByte ] >> offsetRight ) & ( ( 1 << ( diff ? 8 - offsetRight : length ) ) - 1 ) ) + ( diff && ( offsetLeft = ( start + length ) % 8 ) ? ( this.buffer[ lastByte++ ] & ( ( 1 << offsetLeft ) - 1 ) ) << ( diff-- << 3 ) - offsetRight : 0 ); diff; sum += shl( this.buffer[ lastByte++ ], ( diff-- << 3 ) - offsetRight ) );
			return sum;
		};
	}
	p.warn = function( msg ){
		if( this.allowExceptions )
			throw new Error( msg );
		return 1;
	};
	p.decodeFloat = function( data, precisionBits, exponentBits ){
		var b = new this.Buffer( this.bigEndian, data );
		b.checkBuffer( precisionBits + exponentBits + 1 );
		var bias = Math.pow( 2, exponentBits - 1 ) - 1, signal = b.readBits( precisionBits + exponentBits, 1 ), exponent = b.readBits( precisionBits, exponentBits ), significand = 0,
		divisor = 2, curByte = b.buffer.length + ( -precisionBits >> 3 ) - 1;
		do
			for( var byteValue = b.buffer[ ++curByte ], startBit = precisionBits % 8 || 8, mask = 1 << startBit; mask >>= 1; ( byteValue & mask ) && ( significand += 1 / divisor ), divisor *= 2 );
		while( precisionBits -= startBit );
		return exponent == ( bias << 1 ) + 1 ? significand ? NaN : signal ? -Infinity : +Infinity : ( 1 + signal * -2 ) * ( exponent || significand ? !exponent ? Math.pow( 2, -bias + 1 ) * significand : Math.pow( 2, exponent - bias ) * ( 1 + significand ) : 0 );
	};
	p.decodeInt = function( data, bits, signed ){
		var b = new this.Buffer( this.bigEndian, data ), x = b.readBits( 0, bits ), max = Math.pow( 2, bits );
		return signed && x >= max / 2 ? x - max : x;
	};
	p.encodeFloat = function( data, precisionBits, exponentBits ){
		var bias = Math.pow( 2, exponentBits - 1 ) - 1, minExp = -bias + 1, maxExp = bias, minUnnormExp = minExp - precisionBits,
		status = isNaN( n = parseFloat( data ) ) || n == -Infinity || n == +Infinity ? n : 0,
		exp = 0, len = 2 * bias + 1 + precisionBits + 3, bin = new Array( len ),
		signal = ( n = status !== 0 ? 0 : n ) < 0, n = Math.abs( n ), intPart = Math.floor( n ), floatPart = n - intPart,
		i, lastBit, rounded, j, result;
		for( i = len; i; bin[--i] = 0 );
		for( i = bias + 2; intPart && i; bin[--i] = intPart % 2, intPart = Math.floor( intPart / 2 ) );
		for( i = bias + 1; floatPart > 0 && i; ( bin[++i] = ( ( floatPart *= 2 ) >= 1 ) - 0 ) && --floatPart );
		for( i = -1; ++i < len && !bin[i]; );
		if( bin[( lastBit = precisionBits - 1 + ( i = ( exp = bias + 1 - i ) >= minExp && exp <= maxExp ? i + 1 : bias + 1 - ( exp = minExp - 1 ) ) ) + 1] ){
			if( !( rounded = bin[lastBit] ) )
				for( j = lastBit + 2; !rounded && j < len; rounded = bin[j++] );
			for( j = lastBit + 1; rounded && --j >= 0; ( bin[j] = !bin[j] - 0 ) && ( rounded = 0 ) );
		}
		for( i = i - 2 < 0 ? -1 : i - 3; ++i < len && !bin[i]; );
		if( ( exp = bias + 1 - i ) >= minExp && exp <= maxExp )
			++i;
		else if( exp < minExp ){
			exp != bias + 1 - len && exp < minUnnormExp && this.warn( "encodeFloat::float underflow" );
			i = bias + 1 - ( exp = minExp - 1 );
		}
		if( intPart || status !== 0 ){
			this.warn( intPart ? "encodeFloat::float overflow" : "encodeFloat::" + status );
			exp = maxExp + 1;
			i = bias + 2;
			if( status == -Infinity )
				signal = 1;
			else if( isNaN( status ) )
				bin[i] = 1;
		}
		for( n = Math.abs( exp + bias ), j = exponentBits + 1, result = ""; --j; result = ( n % 2 ) + result, n = n >>= 1 );
		for( n = 0, j = 0, i = ( result = ( signal ? "1" : "0" ) + result + bin.slice( i, i + precisionBits ).join( "" ) ).length, r = []; i; j = ( j + 1 ) % 8 ){
			n += ( 1 << j ) * result.charAt( --i );
			if( j == 7 ){
				r[r.length] = String.fromCharCode( n );
				n = 0;
			}
		}
		r[r.length] = n ? String.fromCharCode( n ) : "";
		return ( this.bigEndian ? r.reverse() : r ).join( "" );
	};
	p.encodeInt = function( data, bits, signed ){
		var max = Math.