On Sun, Jan 17, 2016 at 10:17 PM, BartC <b...@freeuk.com> wrote: > On 17/01/2016 08:25, Chris Angelico wrote: >> >> On Sun, Jan 17, 2016 at 6:37 PM, Ian Kelly <ian.g.ke...@gmail.com> wrote: >>> >>> Technically it defaults to non local. The var statement allocates a >>> variable within the current scope. Otherwise it searches up the chain of >>> parent scopes for a matching variable... >> >> >> This far, it's exactly the same as C. >> >>> ... terminating at the global scope. >> >> >> This is the bit that gets ridiculous. Undeclared variables in C are >> compile-time errors. Undeclared variables in JS are implicit globals. >> This is stupid. > > > My own language is something in-between. If a name is not declared locally, > it will look at more global scopes. If nothing is found, it will > auto-declare a local. > > So the JS bug wouldn't occur. However, there is the problem that, given a > perfectly working function with implicitly locals, at some point in the > future someone could introduce a global that will clash with the name of a > local, and screw things up. > > Because of that, the Python scheme is better on the whole. The only issue is > that sometimes you think you're assigning to a global, but it's really a > local if you forget the 'global' declaration within the function.
The Python scheme makes a lot of logical sense. The C scheme (declare everything, otherwise it's an error) makes a lot of logical sense. I've never seen a hybrid scheme that makes as much sense as either of the above. In both Python's and C's ways of doing things, you can look at a single function and know which names are local and which are external. Have fun trying to share code snippets without knowing full context... ChrisA -- https://mail.python.org/mailman/listinfo/python-list
