Argument `max_cost` doesn't seem to be respected

[janluke]

First of all, thank you so much for making this work publicly available :)

Describe the bug
Not sure this is a bug. If it's not, take it as a clarification request.

The max_cost argument is documented as being the "maximum edit distance" allowed between the query and the results. It's not totally clear what it's meant by that (I'd expect the used edit distance corresponds to thefuzz.partial_ratio). Nonetheless, setting max_cost to zero, I still get matches that don't contain the query.

To Reproduce

from fast_autocomplete import AutoComplete

autocomplete = AutoComplete({
    "spiaggia": {},
    "spiaggia al tramonto": {},
    "spiaggia all'alba": {},
})
print(autocomplete.search("spiagggg", max_cost=0))

Output:

[['spiaggia'], ["spiaggia all'alba"], ['spiaggia al tramonto']]

Expected behavior
I'd expect no results are returned.

OS, DeepDiff version and Python version (please complete the following information):

• OS: Windows 10

[seperman]

@janluke You are right. The docs are not explaining it right. max_cost really comes to play when we don't have enough hits from the cheaper search algorithms and we switch to Levenshtein edit distance. In your case the cheaper algorithms found enough hits so the max_cost was never used. The docs need to be updated.