{"description":"github.com For more fine-grained control, if a field implements the MapperValue interface it will be used to decode arguments into the field. package main import ( \"fmt\" \"os\" \"github.com/alecthomas/kong\" ) type Foo struct { Value string } func (foo *Foo) Decode(ctx *kong.DecodeContext) error { var v\u2026","provider_name":"Hatena Blog","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fso-wh.at%2Fentry%2F2025%2F12%2F30%2F145320\" title=\"alecthomas/kong\u3067\u30e6\u30fc\u30b6\u30fc\u5b9a\u7fa9\u578b\uff08Custom decoder\uff09\u3092\u4f7f\u3046 - so what\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_url":"https://blog.hatena.ne.jp/winebarrel/","image_url":null,"blog_title":"so what","blog_url":"https://so-wh.at/","url":"https://so-wh.at/entry/2025/12/30/145320","type":"rich","author_name":"winebarrel","version":"1.0","title":"alecthomas/kong\u3067\u30e6\u30fc\u30b6\u30fc\u5b9a\u7fa9\u578b\uff08Custom decoder\uff09\u3092\u4f7f\u3046","height":"190","width":"100%","categories":[],"published":"2025-12-30 14:53:20","provider_url":"https://hatena.blog"}