Another idea for a switch statement
Hello all. I read PEP 275 but I don't like the syntax of examples. What do you think about something like this? if x case value1 : [...] case value2 : [...] case value3 : [...] else : [...]
Generally, I don't think much of switch statements as they appear in C/C++/Java. Those sorts of things can only switch on trivial data (i.e. ints, chars, strings in C#) and go against the OO grain of the language: They encourage people to store special "behavioral flags" inside objects to modify their behavior with switches, rather than using proper OO inheritance/subclassing. Furthermore, they don't really provide much of a syntactic advantage over chained elifs, or using a delegate dict (which has the advantage of being programmatically modifiable. Both of those are far more flexible and powerful. Unless we're going all the way to F#/Haskell/Scala style 'match' statements (which are completely awesome), there really isn't much point in them. -Haoyi On Tue, Oct 11, 2011 at 6:15 PM, Chris Rebert <pyideas@rebertia.com> wrote:
On Tue, Oct 11, 2011 at 7:33 AM, Lucas Malor <rwwfjchuws@snkmail.com> wrote:
Hello all. I read PEP 275 but I don't like the syntax of examples.
I doubt PEP 275 or PEP 3103 were rejected based just on syntax grounds.
Cheers, Chris _______________________________________________ Python-ideas mailing list Python-ideas@python.org http://mail.python.org/mailman/listinfo/python-ideas
On Wed, Oct 12, 2011 at 8:15 AM, Chris Rebert <pyideas@rebertia.com> wrote:
On Tue, Oct 11, 2011 at 7:33 AM, Lucas Malor <rwwfjchuws@snkmail.com> wrote:
Hello all. I read PEP 275 but I don't like the syntax of examples.
I doubt PEP 275 or PEP 3103 were rejected based just on syntax grounds.
Indeed, they were not. PEP 3103 elaborates on the wide range of design decisions that need to be made in crafting a switch statement for Python. For most of them, all of the available options have some significant downsides. Add in the fact that the desire to use a long if/elif chain in Python often suggests a deeper architectural problem in the relevant code (usually something like "when using Python, write Python, not C"), the idea of adding a new and complicated construct to the language for such a niche use case doesn't garner much support. Cheers, Nick. -- Nick Coghlan | ncoghlan@gmail.com | Brisbane, Australia
participants (4)
-
Chris Rebert -
Haoyi Li -
Lucas Malor -
Nick Coghlan