Hands-On Design Patterns and Best Practices with Julia

Descriptive functions

Although it does not sound very interesting, we can define functions that are solely based on the type itself:

# simple functions on abstract typesdescribe(a::Asset) = "Something valuable"describe(e::Investment) = "Financial investment"describe(e::Property) = "Physical property"

Now, if we ever call describe with a data element that has a supertype of Property, then the description method for Property will be invoked accordingly. As we did not define any description function with the Cash type, when describe is called with a Cash data element it will return the description from the higher-level type, Asset.

Because we have not defined any concrete types yet, we cannot prove the claim here that the describe function for ...