On Sat, Mar 3, 2012 at 4:11 PM, Victor Stinner <victor.stin...@gmail.com> wrote: > Le 29/02/2012 19:21, Victor Stinner a écrit : >> >> Rationale >> ========= >> >> (...) Use cases of frozendict: (...) > > > I updated the PEP to list use cases described in the other related mailing > list thread. > --- > Use cases: > > * frozendict lookup can be done at compile time instead of runtime because > the mapping is read-only. frozendict can be used instead of a preprocessor > to remove conditional code at compilation, like code specific to a debug > build. > * hashable frozendict can be used as a key of a mapping or as a member of > set. frozendict can be used to implement a cache. > * frozendict avoids the need of a lock when the frozendict is shared by > multiple threads or processes, especially hashable frozendict. It would also > help to prohibe coroutines (generators + greenlets) to modify the global > state. > * frozendict helps to implement read-only object proxies for security > modules. For example, it would be possible to use frozendict type for > __builtins__ mapping or type.__dict__. This is possible because frozendict > is compatible with the PyDict C API. > * frozendict avoids the need of a read-only proxy in some cases. frozendict > is faster than a proxy because getting an item in a frozendict is a fast > lookup whereas a proxy requires a function call. > * use a frozendict as the default value of function argument: avoid the > problem of mutable default argument.
Is your implementation (adapted to a standalone type) something you could put up on the cheeseshop? -eric _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
