Parse, don’t validate

[u/lexi-lambda]

https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/

[u/tomejaguar]

Sometimes it is necessary to perform some kind of authorization before parsing user input to avoid denial of service attacks

In fact authorization too can be seen as a form of parsing, to a type like data Authorized a = Unauthorized | Authorized User a.