Does anyone have an idea for an efficient implementation of Jaro–Winkler distance? If there is a built in function with a different name it would be great, please let me know. If not, perhaps a modification of Levenshtein or similar would do or a compiled version (not sure which functions to use to make it compilable). I know good etiquette is to show some code, but I have to compare millions of strings pairwise and need the most efficient approach. Any advice would be appreciated - thanks in advance!

BTW does anyone see any link between Shannon Entropy and Levenshtein and similar distances? Is it possible to talk about distance metric between strings in terms of information change needed to turn one string into the other?