tree e85b057dc4fc3a57e682c3e258936995fd32321d
parent 133c8c412e8539e2bebdaec1a403445719832a8a
author Willy Tarreau <w@1wt.eu> 1615536112 +0100
committer Willy Tarreau <w@1wt.eu> 1615554801 +0100
encoding latin1

MINOR: tools: add simple word fingerprinting to find similar-looking words

This introduces two functions, one which creates a fingerprint of a word,
and one which computes a distance between two words fingerprints. The
fingerprint is made by counting the transitions between one character and
another one. Here we consider the 26 alphabetic letters regardless of
their case, then any digit as a digit, and anything else as "other". We
also consider the first and last locations as transitions from begin to
first char, and last char to end. The distance is simply the sum of the
squares of the differences between two fingerprints. This way, doubling/
missing a letter has the same cost, however some repeated transitions
such as "e"->"r" like in "server" are very unlikely to match against
situations where they do not exist. This is a naive approach but it seems
to work sufficiently well for now. It may be refined in the future if
needed.