checksums

nimony/lib/std/compress/checksums.nim

• type Crc32 = distinct uint32

  A running CRC-32. Kept inverted between updates, as the algorithm wants it; finish undoes that. Distinct so a running value cannot be compared against a finished one by accident — they differ in every bit.

• proc initCrc32(): Crc32
• proc update(c: Crc32; data: openArray[char]): Crc32
• proc finish(c: Crc32): uint32
• proc crc32(data: openArray[char]): uint32

  The CRC-32 of data in one call.

• type Adler32 = distinct uint32

  A running Adler-32: the two 16-bit sums packed as b shl 16 or a, which is also the finished value — there is no final step.

• proc initAdler32(): Adler32
• proc update(c: Adler32; data: openArray[char]): Adler32
• proc finish(c: Adler32): uint32
• proc adler32(data: openArray[char]): uint32

  The Adler-32 of data in one call.