Building diffs for patching lm binaries?

[alexcannan]

I'm curious if it would be possible to build a storage-efficient lm.diff file to patch an older lm.binary file into a newer one. I've experimented with some existing binary diff tools and have found the lm.diff file to be roughly the size of the new lm.binary after compression, but could a smarter tool be built for the kenlm model?

[kpu]

In theory this is possible but you'd be digging into smoothing algorithms because the discount parameters impact probability globally. And the quantizer is free to move centers. Possible but annoying.