Unmarshal function for custom values?

[JamesColeman-LW]

There are sometimes when I want to design a custom value, such as using an iota, and in doing so I want to build a custom unmarshal function. YAML has MarshalYAML and UnmarshalYAML, and JSON has MarshalJSON and UnmarshalJSON which allows me to customize how data in a format is decoded. Does viper have something similar?

[sagikazarmark]

It does: https://sagikazarmark.hu/blog/decoding-custom-formats-with-viper/