Zimpel (Encoding / Decoding of files)

[rmcode]

A small module able to encode and decode files based on the classic LZ78 algorithm.

Instructions

Zimpel can encode and decode strings:

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local Zimpel = require('Zimpel')

local code = Zimpel.encode( "I have come here to chew bubblegum and kick ass...and I'm all out of bubblegum." )
print( code )

local msg = Zimpel.decode( code );
print( msg )

There are also functions for encoding and decoding tables:

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local Zimpel = require('Zimpel')

local example = {
    bubblegum = false,
    kickass = true,
    equipment = {
        "sunglasses",
        "shotgun"
    }
}

local code = Zimpel.encodeTable( example )
print( code )

local dtable = Zimpel.decodeTable( code );
for i, v in pairs( dtable ) do
    print( i, v )
end

Example output for ("Hello World. How are you?"):

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 0H   0e   0l   3o   0    0W   0o   0r   3d   0.   5H   7w   5a   8e   5y   7u   0?

I wrote it for fun, but I thought it might be useful for some people. Could be used to encode save games so they can't be edited (easily).

The code lives on github.

[Jack5500]

So this is basicly serialisation. Can is serialise/encode userdata as well? What about Images?

[rmcode]

Can is serialise/encode userdata as well? What about Images?

Only if you turn them into a string

[zorg]

One could combine the resulting serialized strings from robin's ser/lady/smallfolk with this as well, really useful!

[Frohman]

Not to detract from this, but can't you use love's (now built in) compression wrapper functions to achieve the same thing, faster?
See; https://love2d.org/wiki/love.math.compress and https://love2d.org/wiki/love.math.decompress

Nice work, though!

[rmcode]

Not to detract from this, but can't you use love's (now built in) compression wrapper functions to achieve the same thing, faster?

Most certainly!

Nice work, though!

Thanks - it was fun to write

[zorg]

Not to detract from this, but can't you use love's (now built in) compression wrapper functions to achieve the same thing, faster?

Sure, but love can only use lz4 and DEFLATE algorithms (the latter in two "flavours"), and this one is an LZ78 implementation, so totally different!

[rmcode]

Sure, but love can only use lz4 and DEFLATE algorithms (the latter in two "flavours"), and this one is an LZ78 implementation, so totally different!

DEFLATE is based on LZ77 (IIRC) and then encoded via Huffman. Would be totally futile (= fun) to try writing that one in Lua too

[rmcode]

Small bugfix release:

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# Version 1.0.1 ( 2016-01-20 )
- Fixed encoding of tables containing strings with apostrophes
- Fixed encoding of tables containing sequences