If asked, this user would agree with Simon, for the "several reasons" he 
stated.  There is much to be said for consistency (across platforms and 
functions) and stability (across versions) in software.

MHP

Simon Urbanek wrote on 6/3/2008 10:36 PM:
>
> On Jun 3, 2008, at 8:40 PM, Duncan Murdoch wrote:
>
>> On 03/06/2008 2:35 PM, Mike Prager wrote:
>>> "S Ellison" <S.Ellison@lgc.co.uk> wrote:
>>>> Plaintive squeak: Why the change?
>>>> Some OS's and desktops use the extension, so forgetting it causes
>>>> trouble. The new default filename keeps a filetype (as before) but the
>>>> user now has to type a filetype twice (once as the type, once as
>>>> extension) to get the same effect fo rtheir own filenames. And the
>>>> extension isn't then checked for consistency with valid file types, so
>>>> it can be mistyped and saved with no warning. Hard to see the 
>>>> advantage
>>>> of doing away with it...
>>> Just for the record. . .
>>> This change broke a *lot* of my code, including code used by
>>> others.  Windows depends on file extensions.  Fortunately, fixes
>>> using getRversion are not too difficult.
>>
>> Then you'll be happy to hear that Steve put together a patch and it's 
>> already committed, so it should make it into 2.7.1.  The patch adds 
>> the extension if there's no dot in the name, leaves the filename 
>> as-is if it sees one.  So this should be compatible with the majority 
>> of uses, only messing up cases where people really don't want an 
>> extension (now they'll have to add a dot at the end of their 
>> filename), or where they want an automatic one, but have another dot 
>> in the name.
>>
>
> AFAICS the savePlot() behavior is now (as of r45830) inconsistent 
> across platforms due to the patch (r458229). The inconsistency is IMHO 
> a bad thing - you shouldn't expect the same function to behave 
> differently across platforms.
>
> I'd strongly recommend against this change for several reasons: it 
> changes the behavior of the function between 2.7.0 and 2.7.1, so that 
> now you have to special-case three different versions (pre 2.7.0, 
> 2.7.0 and 2.7.1), there is now no way to specify a file without a dot 
> (which is quite common in non-Windows world) and the behavior is 
> incompatible with other similar functions.
>
> I think the change of behavior in 2.7.0 was deliberate and in favor of 
> consistency, because a filename specification should not be randomly 
> mangled by the function (I have made that mistake myself before, so I 
> know the pitfalls ;)). Extension is part of the filename, it's not a 
> separate concept (also note that ".foo" is a valid  filename that 
> doesn't have an extension). The argument about typos is moot since you 
> can always define functions like
> saveFoo <- function(prefix) savePlot(filename = paste(prefix, "foo", 
> sep="."), type="foo")
> At any rate I don't see how this can realistically be part of 2.7.1 
> since it's not a bugfix and it changes the meaning of a function 
> parameter. (And I usually don't mind disguising small features as 
> bugfixes ;P)
>
> Whether the change in 2.7.0 could be done differently (e.g. using 
> another parameter for a full file name) is a different story, but I 
> suspect that it should have been discussed before the 2.7.0 release...
>
> Cheers,
> Simon
>

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