On Wednesday, 3 April 2013 at 09:40:27 UTC, Lars T. Kyllingstad
wrote:
For arrays, RangeError is synonymous with "out of bounds". I
see no reason to invent a new class just for this purpose.
Exactly, no need for RangeError (as out of bound access can be
produced in many situation that don't involve ranges).
And note that I'm not saying that ranges should be restricted
to *only* throwing RangeErrors. Generally, it should be used
in situations that are analogous to out of bounds for arrays,
such as trying to pop past the end of the range.
The data always come from somewhere. That somewhere can't provide
anymore data for a reason. Because you reached the end of a file
(IOException or something) because the network disconnected
(NetworkException) or whatever.
RangeError imply that the data magically appears from a range,
without any actual source, which is impossible.
However, some ranges may want to do something else in this
situation. An output range that writes to a file, for
instance, may want to throw a "disk full" exception. A wrapper
range may simply propagate any errors from the underlying range.
Exactly. In general, wrapper should simply forward calls and let
the source fail when its own logic isn't involved.
RangeError is for the cases when it is not possible/necessary
to provide more detail than "you tried to call popFront on an
empty range, which is illegal".
It is always illegal for a reason.
