Datasette plugin that adds custom SQL functions for fuzzy string matching, built on top of the Double Metaphone Python library.

As SQLite custom functions must return a string, we have separate calls for the two results, or one that returns a JSON array of the two results.

Examples:

SELECT double_metaphone_main("richard");
    -- Outputs 'RXRT'
SELECT double_metaphone_alt("richard");
    -- Outputs 'RKRT'
SELECT double_metaphone_json("richard");
    -- Outputs '["RXRT", "RKRT"]'