Is inherited class a derivative work?

Greg London greglondon at
Sat Oct 13 15:47:58 UTC 2001

Michael Beck wrote:
> Some people believe that when you subclass a new class, 
> you are creating a "derivative work" in the copyright sense, 
> especially when you override existing methods. 

> The scary scenario is that somebody will inherit a
> class, make some modifications to it, and then claim 
> that since it's not a "derivative work", 
> s/he doesn't have to publish it, 
> and the new class is his own proprietary code.


interesting fear you've got there.

first of all, you're mixing USE (inherit)
with MODIFY. A derived class is not a modification
of the original.

say Alice writes a class, "AlicesRestaurant", which 
does whatever it does, and it contains
a method called "pretty_print"

sub pretty_print
	print "$line_number $text \n";

Bob comes along, inherits from the 
class AlicesRestaurant, and does this
solely for the purpose of overriding the
pretty_print method.

sub pretty_print
	# 5,000 lines of code

And your fear is that Bob will claim 
that his pretty_print code is proprietary.

that's an interesting fear you've got there.

Just what, exactly, did Alice do that allows
her to claim Bob's 5000 lines of code as
derived work? I'll emphasize the word WORK,
in this case, since Alice didn't do a damn
thing to create those 5000 lines of code.

"well, she wrote the original method,
and Bob overrode the method by writing
a method of the same name."

Is using the same method name
"pretty_printer" the same as using
the name "Luke Skywalker" in a novel?

if I write a sci-fi epic about 
Luke Skywalker, Han-Solo, and Princess Leia,
without first getting Lucas's approval,
I'd be in hot water.

this is basically how you're looking at class
inheritance. And I don't think it applies.

Good God, I hope not. 

If you accept this premise, then it
is impossible to use anyone's code
without it being a derived work.

"USE" and "DERIVED WORKS" become collapsed.
Any USE becomes a DERIVED WORK.

Alice's pretty_print method is simply
an interesting plot twist in an entire novel. 

The butler did it.

you can still have an endless supply
of mystery novels where the butler did it,
and not infringe on each other.
They just do it in different ways.

Bob's pretty_print method is the same
plot twist, but he implements it in 
a completely independent way.

Alice should probably be reminded that
she saw code in textbooks at school that 
contained pretty_print methods of their
own. So, by her own standards, her
code is actually a derived work of
someone else's.

By her premise, all fiction is derived
from ancient greek mythology,

and all source code is derived from 
Ada Lovelace.

Alice needs to chill out a bit.
Not all code flows from her.


Greg "There is nothing new under the sun" London
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