
On Wed, Oct 24, 2018 at 7:55 AM Rhodri James <rhodri@kynesim.co.uk> wrote:
On 24/10/2018 15:04, Calvin Spealman wrote:
My idea is not "assignment blocks" those already exist. `def` and `class` blocks are both syntaxes that assign to some name. I'm just using the term to refer to them as a group.
The proposal is just being able to return them. These two examples become equivalent:
def ignore_exc(exc_type): return def (func): @wraps(func) return def (*args, **kwargs): try: return func(*args, **kwargs) except exc_type: pass
def ignore_exc(exc_type): def decorator(func): @wraps(func) def wrapped_func(*args, **kwargs): try: return func(*args, **kwargs) except exc_type: pass return wrapped_func return decorator
Essentially this is a limited multi-line lambda. Either people are going to be surprised that you can only use it in a return statement or you have to open the whole can of worms about multi-line lambdas. Good luck on the latter.
Let's close that can quickly. Syntactically this is much simpler because because there's no trouble with switching between expression-mode and statement-mode. Also note that syntactically it is clearly a special form of `def` statement -- it can even be decorated! So let's review the proposal as a shorthand for defining a function and immediately returning it. It saves one line plus picking a name. I personally don't think that's enough of a benefit to warrant the extra syntactic complexity (even if modest). -- --Guido van Rossum (python.org/~guido)