Ruby

Add copy with changes functionality for Data objects (#6766)

Implements [Feature #19000]

This commit adds copy with changes functionality for Data objects
using a new method Data#with.

Since Data objects are immutable, the only way to change them is by
creating a copy. This PR adds a with method for Data class instances
that optionally takes keyword arguments.

If the with method is called with no arguments, the behaviour is the
same as the Kernel#dup method, i.e. a new shallow copy is created
with no field values changed.

However, if keyword arguments are supplied to the with method, then
the copy is created with the specified field values changed. For
example:

 Point = Data.define(:x, :y) point = Point.new(x: 1, y: 2) point.with(x: 3) # => #<data Point x: 3, y: 2> 

Passing positional arguments to with or passing keyword arguments to
it that do not correspond to any of the members of the Data class will
raise an ArgumentError.

Co-authored-by: Alan Wu XrXr@users.noreply.github.com