kastiglione added inline comments.
================
Comment at: lldb/examples/python/crashlog.py:434
except CrashLogFormatException:
- return TextCrashLogParser(debugger, path, verbose).parse()
+ return object().__new__(TextCrashLogParser)
----------------
mib wrote:
> JDevlieghere wrote:
> > mib wrote:
> > > kastiglione wrote:
> > > > I have not seen the `object().__new__(SomeClass)` syntax. Why is it
> > > > being used for `TextCrashLogParser` but not `JSONCrashLogParser`? Also,
> > > > `__new__` is a static method, could it be `object.__new__(...)`? Or is
> > > > there a subtly that requires an `object` instance? Somewhat related,
> > > > would it be better to say `super().__new__(...)`?
> > > >
> > > > Also: one class construction explicitly forwards the arguments, the
> > > > other does not. Is there a reason both aren't implicit (or both
> > > > explicit)?
> > > As you know, python class are implicitly derived from the `object` type,
> > > making `object.__new__` and `super().__new__` pretty much the same thing.
> > >
> > > In this specific case, both the `TextCrashLogParser` and
> > > `JSONCrashLogParser` inherits from the `CrashLogParser` class, so
> > > `JSONCrashLogParser` will just inherits `CrashLogParser.__new__`
> > > implementation if we don't override it, which creates a recursive loop.
> > > That's why I'm calling the `__new__` method specifying the class.
> > What's the advantage of this over this compared to a factory method? Seems
> > like this could be:
> >
> > ```
> > def create(debugger, path, verbose)
> > try:
> > return JSONCrashLogParser(debugger, path, verbose)
> > except CrashLogFormatException:
> > return TextCrashLogParser(debugger, path, verbose)
> > ```
> If we make a factory, then users could still call `__init__` on
> `CrashLogParser` and create a bogus object. With this approach, they're
> forced to instantiate a CrashLogParser like any another object.
`CrashLogParser.__init__` could raise an exception. With intricacy of this
approach, maybe it's better to use a factor method combined with an exception
if the base class `__init__` is called.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D131085/new/
https://reviews.llvm.org/D131085
_______________________________________________
lldb-commits mailing list
lldb-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
