Proposal: q-gram GIN and GiST indexes

Hackers,

I would like to ask you about currency of the work above. I propose to
develop functionality of GIN and GiST q-gram indexes with following
features:
1) Handle edit distance (e.g. levenshtein distance) and LIKE/ILIKE
queries(using GIN partial match if no full q-grams can be extracted
from wildcard)
2) Support of various q
3) Support of positional q-grams in GIN (for more effective edit
distance filtering)
4) Various signature size in GiST
As you can see, there are some significant differences from pg_trgm.
Do you see this functionality useful? If you think this functionality
useful, where do you like to see it: separate project, contrib module,
core (of course, in the case when code have sufficient quality)?
I have stong confidence level about implementability of this project
in few month. That's why I could propose this as an GSoC project.

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With best regards,
Alexander Korotkov.