Burrows–Wheeler transform

[capellan]

Hi All,

Today, I found this old stack and cleaned it a bit before posting.
Maybe this old stack could works as a starting point for someone
who needs to use it:

The Burrows–Wheeler transform (BWT, also called block-sorting compression)
rearranges a character string into runs of similar characters.

This is useful for compression, since it tends to be easy to compress a string
that has runs of repeated characters by techniques such as move-to-front
transform and run-length encoding.

More importantly, the transformation is reversible, without needing to store
any additional data.

The BWT is thus a "free" method of improving the efficiency of text compression
algorithms, costing only some extra computation.

Al

Burrows Wheeler Transform v02.zip

[capellan]

Looks like I forgot to include the first and last characters
in the code. Please, also check online other BWT implementations.
For example:
https://rosettacode.org/wiki/Burrows%E2 ... _transform

Al

[bogs]

Very nice Al!

[[-hh]]

Hi Al.

Here in the forum your post will soon get cold. Why don't you add your code to rosettacode?
There are already several LiveCode contributions there (most of them by Geoff).

[capellan]

Hi Bogs and Hermann,

Thanks a lot for taking time for checking this post.

Hermann wrote:
Here in the forum your post will soon get cold. Why don't you add your code to rosettacode?
There are already several LiveCode contributions there (most of them by Geoff).

I will check how I could do this. Now there are many more LiveCode examples
in Rosetta Code than the last time I visited them:

https://rosettacode.org/wiki/Category:LiveCode

Al

[EDIT: Now I remember that years ago, I had posted a CRC32 livecode script.
I will try to find it and test thoroughly before including in Rosetta Code]