[ruby-talk:15863] Experimental "in" operator for collections

There's one thing where I prefer Python over Ruby.  Testing whether an
object is included in some collection happens so often, that a special
syntax just looks better.

Just to test how Ruby would feel like, I modified the system to allow 

  object in array

and

  object not in array

as new kinds of expressions.  Internally, Ruby uses "include?" (in the
second case inverted as with "not") to perform the test.  IMHO it
nicely fits into the language.

A patch to parse.y (1.6.4) is attached.  I hacked this into the file
with a lot of trail and error, you I cannot guarantee that it is
working in all cases.

----snip----

251a252
> %nonassoc  kIN
748a750,757
> 		| arg kIN arg
> 		    {
> 			$$ = call_op($3, rb_intern("include?"), 1, $1);
> 		    }
> 		| arg kNOT kIN arg
> 		    {
> 			$$ = NEW_NOT(cond(call_op($4, rb_intern("include?"), 1, $1)));
> 		    }
4773a4783
>     kIN,	"in",

bye
-- 
Stefan Matthias Aust \/ Truth Until Paradox