[Rd] "Unfelicity" :-) with edit()
murdoch at stats.uwo.ca
Tue May 9 15:31:12 CEST 2006
On 5/9/2006 9:17 AM, François Pinard wrote:
> [Duncan Murdoch]
>>I'll fix it.
> Thanks, Duncan. While I quite understand that more serious work should
> be done within real sources files, fixing and editing is still useful
> for quick, evanescent interactive toying.
>>edit() is a hack, so you should expect problems. You're better off
>>keeping your source in an editor and using source() to get it.
> This is not the first time I read such a remark. Maybe it would be
> worth a note within ?edit.
>>There is no way it could preserve the environment of a function [...]
> That might be worth another note within ?edit.
> Speaking of which, this "x <- edit()" usage (interactively suggested by
> fix when it fails to re-parse the result of edition) is not covered by
> ?edit. I mean that by reading ?edit, one does not get information about
> what a mere "edit()" does. It might be useful that ?edit says a few
> words about this particular usage.
Yes, it probably would be. Just to clarify: fix(f) *does* preserve the
environment of f, but
fix(f) # introduce a syntax error
f <- edit()
> The remaining of this message quotes the original message:
> [François Pinard]
>>Hi, people. This is about R 2.3.0 under Linux.
>>It seems that edit() may change a function environment. Here is
>>a transcript, more comments follow:
>>Erreur dans edit(name, file, title, editor) :
>> une erreur s'est produite à la ligne 3
>> utilisez une commande du genre
>> x <- edit()
>> pour corriger
>>>f <- edit()
>>The initial ``fix(f)`` called an editor, which I exited right away. For
>>the second ``fix(f)``, I used the editor for adding a slash between
>>braces, and exited. The French comment produced by R speaks about an
>>error at line 3 and suggests using something like ``x <- edit()`` to
>>make a correction. On the third call to the editor, I remove the slash
>>and exit. Now, the environment of the function became "base".
>>This has unfortunate effects when editing a more substantial function,
>>because for example, "stats" or "utils" is not readily available anymore
>>after the editing. Is it reasonable to suggest an improvement in the
>>mechanics of edit(), for alleviating this drawback ?
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