ASCII Folding Token Filter

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A token filter of type asciifolding that converts alphabetic, numeric, and symbolic Unicode characters which are not in the first 127 ASCII characters (the "Basic Latin" Unicode block) into their ASCII equivalents, if one exists. Example:

PUT /asciifold_example
{
    "settings" : {
        "analysis" : {
            "analyzer" : {
                "default" : {
                    "tokenizer" : "standard",
                    "filter" : ["standard", "asciifolding"]
                }
            }
        }
    }
}

Accepts preserve_original setting which defaults to false but if true will keep the original token as well as emit the folded token. For example:

PUT /asciifold_example
{
    "settings" : {
        "analysis" : {
            "analyzer" : {
                "default" : {
                    "tokenizer" : "standard",
                    "filter" : ["standard", "my_ascii_folding"]
                }
            },
            "filter" : {
                "my_ascii_folding" : {
                    "type" : "asciifolding",
                    "preserve_original" : true
                }
            }
        }
    }
}