编辑“︁模板:Lang/doc”︁（章节）

===The function selector parameter===
{{tlx|lang}} uses the Lua function <code>lang()</code> [[Module:Lang]]. That module also supports all of the {{tnull|lang-??}} templates using the Lua functions <code>lang_xx_inherit()</code> and <code>lang_xx_italic()</code>. The module has other functions that may be useful. The function selector parameter {{para|fn}} tells module:lang which function to execute. The available functions are:
*<code>is_ietf_tag</code> – returns <code>true</code> if the provided [[IETF language tag]] is valid; nil else
**<code><nowiki>{{lang|fn=is_ietf_tag|nv}}</nowiki></code> →{{lang|fn=is_ietf_tag|nv}}←
**<code><nowiki>{{lang|fn=is_ietf_tag|xx}}</nowiki></code> →{{lang|fn=is_ietf_tag|xx}}←
*<code>is_lang_name</code> – returns <code>true</code> if the provided language name is valid; nil else
**<code><nowiki>{{lang|fn=is_lang_name|navajo}}</nowiki></code> →{{lang|fn=is_lang_name|navajo}}←
**<code><nowiki>{{lang|fn=is_lang_name|xxxxx}}</nowiki></code> →{{lang|fn=is_lang_name|xxxxx}}←
*<code>lang</code> – the function that renders {{tlx|lang}}; listed here for completeness, this particular usage is more-or-less pointless
*<code>name_from_tag</code> – returns the language name associated with the provided IETF language tag:
**<code><nowiki>{{lang|fn=name_from_tag|apa}}</nowiki></code> → {{lang|fn=name_from_tag|apa}}
*<code>tag_from_name</code> – returns the ISO 639 language code (sometimes IETF language tag) associated with the provided language name:
**<code><nowiki>{{lang|fn=tag_from_name|havasupai}}</nowiki></code> → {{lang|fn=tag_from_name|havasupai}}
*<code>transl</code> – the function that renders {{tlx|transl}}; listed here for completeness, this particular usage is more-or-less pointless
**<code><nowiki>{{lang|fn=transl|ar|DIN|al-Ḫawārizmī}}</nowiki></code> → {{lang|fn=transl|ar|DIN|al-Ḫawārizmī}}