package gf256

Import Path
	rsc.io/qr/gf256 (on go.dev)

Dependency Relation
	imports one package, and imported by one package

Involved Source Files

	  d gf256.go
		Package gf256 implements arithmetic over the Galois Field GF(256).
Package-Level Type Names (total 2, both are exported)

	/* sort exporteds by: alphabet | popularity */
	 type Field (struct)
		A Field represents an instance of GF(256) defined by a specific polynomial.

		Fields (total 2, neither is exported)
			/* 2 unexporteds ... *//* 2 unexporteds: */
			exp [510]byte
			log [256]byte
				// log[0] is unused

		Methods (total 6, in which 5 are exported)
			(*Field) Add(x, y byte) byte
				Add returns the sum of x and y in the field.

			(*Field) Exp(e int) byte
				Exp returns the base-α exponential of e in the field.
				If e < 0, Exp returns 0.

			(*Field) Inv(x byte) byte
				Inv returns the multiplicative inverse of x in the field.
				If x == 0, Inv returns 0.

			(*Field) Log(x byte) int
				Log returns the base-α logarithm of x in the field.
				If x == 0, Log returns -1.

			(*Field) Mul(x, y byte) byte
				Mul returns the product of x and y in the field.

			/* one unexported ... *//* one unexported: */
			(*Field) gen(e int) (gen, lgen []byte)
		As Outputs Of (at least one exported)
			func NewField(poly, α int) *Field
		As Inputs Of (at least one exported)
			func NewRSEncoder(f *Field, c int) *RSEncoder
		As Types Of (only one, which is exported)
			  var rsc.io/qr/coding.Field *Field

	 type RSEncoder (struct)
		An RSEncoder implements Reed-Solomon encoding
		over a given field using a given number of error correction bytes.

		Fields (total 5, none are exported)
			/* 5 unexporteds ... *//* 5 unexporteds: */
			c int
			f *Field
			gen []byte
			lgen []byte
			p []byte
		Methods (only one, which is exported)
			(*RSEncoder) ECC(data []byte, check []byte)
				ECC writes to check the error correcting code bytes
				for data using the given Reed-Solomon parameters.

		As Outputs Of (at least one exported)
			func NewRSEncoder(f *Field, c int) *RSEncoder


Package-Level Functions (total 6, in which 2 are exported)

	 func NewField(poly, α int) *Field
		NewField returns a new field corresponding to the polynomial poly
		and generator α.  The Reed-Solomon encoding in QR codes uses
		polynomial 0x11d with generator 2.
		
		The choice of generator α only affects the Exp and Log operations.

	 func NewRSEncoder(f *Field, c int) *RSEncoder
		NewRSEncoder returns a new Reed-Solomon encoder
		over the given field and number of error correction bytes.

	/* 4 unexporteds ... *//* 4 unexporteds: */
	 func mul(x, y, poly int) int
		mul returns the product x*y mod poly, a GF(256) multiplication.

	 func nbit(p int) uint
		nbit returns the number of significant in p.

	 func polyDiv(p, q int) int
		polyDiv divides the polynomial p by q and returns the remainder.

	 func reducible(p int) bool
		reducible reports whether p is reducible.

The pages are generated with Golds v0.6.7. (GOOS=linux GOARCH=amd64)
Golds is a Go 101 project developed by Tapir Liu.
PR and bug reports are welcome and can be submitted to the issue list.
Please follow @Go100and1 (reachable from the left QR code) to get the latest news of Golds.