Adding Type Support to Copy

Just like how Copy is meant to be flexible, it’s also meant to be extensible. If a new copyable datatype comes out (like Random), it might be useful to specify a method for copying it. This page will be covering how to do just that.

There are two ways to copy a value, replacing and reconciling.

• Replacing - creating a new value from an old value
• Reconciling - mapping an old value’s state to a pre-existing value

Both of these methods expect the same return values:

• success: boolean - whether the value was successfully copied; if false, no further arguments are needed
• doSet: boolean - whether the value should be assigned on its super-value; if false, no further arguments are needed
• newValue: T - the new value to set

Replacing

(self: Copy, oldValue: T) -> (success: boolean, doSet: boolean, newValue: T)

Parameters:

• self: Copy - the module doing the copying
• oldValue: T - the old value being used as a blueprint

There are two required tasks the function has to complete when replacing a value.

1. Creating the new value
2. Mapping the old value to the new one in self.Transform

Reconciling

(self: Copy, oldValue: T, newValue: T) -> (success: boolean, doSet: boolean, newValue: T)

Parameters:

• self: Copy - the module doing the copying
• oldValue: T - the value to copy from
• newValue: T - the value to copy to