On Sunday, January 22, 2017, Wes Turner <wes.turner@gmail.com> wrote:
On Sunday, January 22, 2017, Soni L. <fakedme+py@gmail.com <javascript:_e(%7B%7D,'cvml','fakedme%2Bpy@gmail.com');>> wrote:
On 22/01/17 10:03 PM, Wes Turner wrote:
On Sunday, January 22, 2017, Wes Turner <wes.turner@gmail.com> wrote:
Have you looked at pyrsistent for immutable/functional/persistent/copy-on-write data structures in Python?
https://github.com/tobgu/pyrsistent/
(freeze() / thaw())
... e.g. List and Dict NamedTuple values are not immutable (because append() and update() still work)
fn.py also has immutables: https://github.com/kachayev/fn.py/blob/master/README.rst#per sistent-data-structures
You seem to be thinking of "immutable object builder". Not "the builder itself is immutable and operations on it create new builders".
My mistake. Something like @optionable and/or @curried from fn.py in conjunction with PClass from pyrsistent may accomplish what you describe?
From http://pyrsistent.readthedocs.io/en/latest/api.html#pyrsistent.PClass.set : "Set a field in the instance. Returns a new instance with the updated value. The original instance remains unmodified. Accepts key-value pairs or single string representing the field name and a value."
On Sunday, January 22, 2017, Soni L. <fakedme+py@gmail.com> wrote:
I've been thinking of an Immutable Builder pattern and an operator to go with it. Since the builder would be immutable, this wouldn't work:
long_name = mkbuilder() long_name.seta(a) long_name.setb(b) y = long_name.build()
Instead, you'd need something more like this:
long_name = mkbuilder() long_name = long_name.seta(a) long_name = long_name.setb(b) y = long_name.build()
Or we could add an operator to simplify it:
long_name = mkbuilder() long_name .= seta(a) long_name .= setb(b) y = long_name.build()
(Yes, I'm aware you can x = mkbuilder().seta(a).setb(b), then y = x.build(). But that doesn't work if you wanna "fork" the builder. Some builders, like a builder for network connections of some sort, would work best if they were immutable/forkable.) _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/