ZLib
is a high-level wrapper around zlib.
Installation
(load "git@git.veitheller.de:carpentry/zlib.git@0.0.2")
Usage
The ZLib module provides only two functions, inflate and
deflate. These functions work in tandem to provide you with data
compression.
; deflate returns a Result of either binary data or an error message
(let [deflated (ZLib.deflate "mystring")]
(match deflated
; inflate returns a Result of either a string or an error message
(Success bin) (println* &(inflate bin))
(Error msg) (IO.errorln &msg)))
Because it’s a Result type, we can apply combinators to it.
(=> (ZLib.deflate "mystring")
(Result.and-then &ZLib.inflate)
(Result.map-error &(fn [msg] (do (println* &msg) msg)))
)
You can also choose different levels of compression using inflate-with. The
levels are defined in ZLib.ZLevel, and are NoCompression,
BestSpeed, BestCompression, and DefaultCompression, which is, well, the
default.
ZLevel
Module
is a type used in conjunction with
deflate-with. It controls the compression level.
The constructors are NoCompression, BestSpeed, BestCompression, and
DefaultCompression, which is, well, the default.
deflate
(Fn [(Ref String a)] (Result ZLib.ZBytes String))
(deflate s)
takes a bytes object s and returns a Result.
The Result will be a Success containing the deflated bytes if all goes
well, and an Error returning an error message otherwise.
It is equivalent to calling deflate-with with
(ZLevel.DefaultCompression).
deflate-with
(Fn [(Ref String a), ZLib.ZLevel] (Result ZLib.ZBytes String))
(deflate-with s level)
takes a bytes object s, a Zlevel level and returns
a Result.
The Result will be a Success containing the deflated bytes if all goes
well, and an Error returning an error message otherwise.
inflate
(Fn [ZLib.ZBytes] (Result String String))
(inflate s)
takes a bytes object s and returns a Result.
The Result will be a Success containing the inflated string if all goes
well, and an Error returning an error message otherwise.