[[analysis-asciifolding-tokenfilter]]
=== ASCII Folding Token Filter

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:

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

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:

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