Default mutable parameters in functions

Fri Apr 4 19:38:20 EDT 2014

In article <mailman.8908.1396653807.18130.python-list at python.org>,
 Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
> On 2014年4月04日 10:00:25 -0400, random832 at fastmail.us declaimed the
> following:
>> >
> >I can't imagine a language that would work that way. For one, it would
> >also imply that passing a value would change the default for future
> >calls even for non-mutable types.
>> 	Some early FORTRAN compilers purportedly had problems with, for
> example:
>> 	X = 1
> 	call mutant(1)
> 	Y = 1
>> where
>> 	subroutine mutant(y)
>> 	y = y + 1
> 	return
>> meant that Y now held the value of 2 -- that is, literals were stored in
> mutable memory, and since FORTRAN passes by reference, the address of the
> literal is passed, and the assignment changed the "constant".

Problem? I always assumed it was a feature :-)