SYNOPSIS
a bn.js factory wrapper that constrains numbers to a fixed width
USAGE
const FixedBN = require('fixed-bn.js')
// there are some built in sizes `U64`, `U128`, `U160`, `U256`
const bnNum = new FixedBN.U64('0x5555555')
// use normal bn.js methods
bnNum.iaddn(55)
// toBuffer and toArray allways produces a fixed length result
bnNum.toBuffer()
// <Buffer 00 00 00 00 05 55 55 55>
// you can also create an arbitary fixed lenght bn
// max bit lenght is 199 bits and min length is 2 bits
const I199 = FixedBN(199, 2)
const newBnNum = new I199(390248)API
Since this module extends BN.js it has the methods as it does plus a few extras.
factory
A factory that produces BN.js constructors for a given width
Parameters
maxWidthInteger the max length in bits that the bn.js instance can handleminWidthInteger the min length in bits that the bn.js instance can handle
Returns bn.js returns a bn.js constuctor that that is constained to maxWidth and minWidth
builtin length
the factory has the following builtins
FixedBN.U64FixedBN.U128FixedBN.U160FixedBN.U256
bn.js instance
Each instance has the following additional methods
maxWidth
retuns Max Width
Returns integer
minWidth
retuns Min Width
Returns integer
fromBuffer
converts a buffer to a fixed-bn.js
Parameters
isFixBN
checks if a BN instance is a fixed BN instance
Parameters
bnbn.js
isSameWidth
checks if a fixed-bn instance is the same width as the contructor
Parameters
fixBNbn.js