

Task

Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.



The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.

Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and complements the final CRC.

For the purpose of this task, generate a CRC-32 checksum for the ASCII encoded string:

 The quick brown fox jumps over the lazy dog


(let [crc (new java.util.zip.CRC32)
      str "The quick brown fox jumps over the lazy dog"]
  (. crc update (. str getBytes))
  (printf "CRC-32('%s') = %s\n" str (Long/toHexString (. crc getValue))))