| > If I were to write this in F#, there would be a type `Within5BusinessDays` That’s not really the same thing - it’sa valid alternative approach but you’ve lost the benefits of a simple date - from (de)serialisation to the rich support for simple date types in libraries and other functions, the simple at-a-glance understanding that future readers could enjoy. Now the concept of date has been complected with some other niche concern. > the type can become invalid after literally 1 second Every system I’ve ever seen that has the concept of a business date strictly doesn’t derive it from wall clock date. E.g. it’s common that business date would be rolled at some convenient time (and most often not midnight) so you’d be free to ensure no impacts possible from the date roll. >> I believe you can do the same with types, especially if the type system support generics You can do something similar but you’ll need to change the system’s code. It would be almost like gradual typing, except you could further choose to turn it off or to substitute your own types / schema without making changes to the system / code. It’s quite a lot more flexible. (Apols for slow reply - i 1up’d your reply earlier when i saw it but couldn’t reply then) |
I see what you mean - thanks!
> you could further choose to turn it off or to substitute your own types / schema without making changes to the system / code
This is still unclear to me. How can you make changes (turning off gradual typing/substituting your own schema) without making changes to code?