Hands-On Design Patterns and Best Practices with Julia

Using traits with a different type of hierarchy

The best part of the holy trait pattern is that we can use it with any object, even when its type belongs to a different abstract type hierarchy. Let's explore the case of literature, where we may define its own type hierarchy as follows:

abstract type Literature endstruct Book <: Literature    nameend

Now, we can make it obey the LiquidityStyle trait, as follows:

# assign traitLiquidityStyle(::Type{Book}) = IsLiquid()# sample pricing functionmarketprice(b::Book) = 10.0

Now, we can trade books, just like other tradable assets.