Re: [Haskell-cafe] ANNOUNCE: hs-cryptohash 0.4

Vincent Hanquez writes:

On Fri, Jul 02, 2010 at 12:55:03PM +1000, Ivan Miljenovic wrote:

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On 1 July 2010 17:25, Vincent Hanquez wrote:

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The main reason for this library is the lack of incremental api exposed by current digest libraries, and filling the void about some missing digest algorithms; Also the speed comes as a nice bonus.

Can you explain what you mean by "incremental API"?

The incremental API is the init/update/finalize functions where you can call update as many time as you need, instead of a single function "hash" where you need to hash all your data in one-go.

It's necessary in my case since i receive chunks of data to be hashed from the network, and I don't want to carry a buffer of data (with potential security issues), until i can hash everything.

The few existing packages that exposes the incremental API, usually do it in the IO monad; cryptohash do it purely, creating a new context as it get updated. (this has a cost but remains fast globally with the C implementation)

i.e. update : ctx -> bytestring -> IO () becomes: update : ctx -> bytestring -> ctx

So you're using explicit state parsing? Any particular reason for not using the State monad or something like that? -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com