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Available inall subroutines.

Similar to accept.language_lookup, this function selects the best matches from a string in the format of an Accept-Language header's value in the listed languages using the algorithm described in RFC 4647, Section 3.3.1.

This function takes the following parameters:

1. a colon-separated list of languages available for the resource,
2. a fallback return value,
3. a string representing an Accept-Language header's value,
4. the maximum number of matching languages to return.

The matches are comma-separated.

Example

set bereq.http.Accept-Language =
  accept.language_filter_basic("en:de:fr:nl", "nl",
    req.http.Accept-Language, 2);