elasticsearch - Elasticsearch的单词定界符过滤器类型表的有效类型是什么？

Question

Elasticsearch's Word Delimiter filter有一个非常有用的选项type_table；它使您可以将特殊字符转换为 token 的合法字符。

但是，它的文档非常稀疏:

type_table
A custom type mapping table, for example (when configured using type_table_path):
    # Map the $, %, '.', and ',' characters to DIGIT
    # This might be useful for financial data.
    $ => DIGIT
    % => DIGIT
    . => DIGIT
    \\u002C => DIGIT

    # in some cases you might not want to split on ZWJ
    # this also tests the case where we need a bigger byte[]
    # see http://en.wikipedia.org/wiki/Zero-width_joiner
    \\u200D => ALPHANUM

从该示例中，我们可以看出 DIGIT和 ALPHANUM是我们可以映射字符的有效选项。还有哪些其他选择，它们又做什么？

Answer 1

我通过深入研究Lucene文档找到了答案，该文档基本上引用了Elasticsearch。

WordDelimiterFilterFactory的文档链接到this file in the Subversion repository。它在Elasticsearch文档中被大量引用，但包含以下附加代码段:

A customized type mapping for WordDelimiterFilterFactory the allowable types are: LOWER, UPPER, ALPHA, DIGIT, ALPHANUM, SUBWORD_DELIM