nupp.checksum

Incremental numeric checksums for accidental corruption detection. The canonical CRC variants are crc32-ieee, crc32c and crc64-ecma (ECMA-182, non-reflected, zero initialization and zero final xor). Adler-32 is adler32. value() is a non-consuming snapshot; protocol code chooses byte order when serializing the number. These algorithms provide no authentication.

Setup selects a typed catalog through nupp.runtime.services.checksum before this module loads. Initialization validates and retains algorithm descriptors. An explicit selection overrides matching built-ins and may add names; unselected built-ins remain available. Lookup and context operations use the retained catalog without SPI resolution. Provider names identify implementations, independently of the algorithm names in their catalogs.

record Algorithm
    readonly name: string
    readonly width: integer
    function create(self): Checksum end
end

create: function create(self): Checksum

name: string

width: integer

affine interface Checksum is nupp.Closeable
    terminal close: nosuspend function(takes self: Checksum): nil
    algorithm: function(self: Checksum): string
    width: function(self: Checksum): integer
    update: function(exclusive self: Checksum, bytes: string): nil
    updateSpan: function(exclusive self: Checksum, borrows bytes: span.ByteSpan): nil
    value: function(self: Checksum): uint64
end

close: nosuspend function(takes self: Checksum): nil

algorithm: function(self: Checksum): string

width: function(self: Checksum): integer

update: function(exclusive self: Checksum, bytes: string): nil

updateSpan: function(exclusive self: Checksum, borrows bytes: span.ByteSpan): nil

value: function(self: Checksum): uint64

function algorithm(name: string): Algorithm

function algorithms(): {string}

function create(name: string): Checksum

function lookup(name: string): Algorithm?

function value(name: string, bytes: string): uint64