I do not want to access the slot itself but its content: a:toto would be
a...@slot1[['toto']].
The thing is that I would like to have two different methods: '$' (that
I already have) and another one to define, ideally that behaves like '$'.
So in brief:
- a:toto would be for a...@slot1[['toto']]
- a$tata would be for a...@slot2[['tata']]
But apparently it might not be possible.
--
Renaud Gaujoux
Computational Biology - University of Cape Town
South Africa
On 09/07/2010 14:58, Marc Schwartz wrote:
You were, in effect, trying to overload the ":" operator, which is of course
for defining sequences.
If you are using S4 methods, what is wrong with using the default "@" as the
extraction syntax (eg. a...@name) to get at slots?
See ?"@" and ?slot
HTH,
Marc Schwartz
On Jul 9, 2010, at 7:49 AM, Renaud Gaujoux wrote:
Alright.
Maybe the symbol I chose was not appropriate. I tried ':' to be able to do
'a:name' with 'a' a S4 object.
I get the following error:
Error in genericForPrimitive(f) :
methods may not be defined for primitive function ":" in this version of R
Does there exist any symbol that would be suitable for the job?
Thanks
--
Renaud Gaujoux
Computational Biology - University of Cape Town
South Africa
On 09/07/2010 14:29, Duncan Murdoch wrote:
On 09/07/2010 8:18 AM, Renaud Gaujoux wrote:
Hi,
is there a way to define a method say '$$' that would behave like '$' and allow
calls like 'a$$name'?
No, the parser handles a fixed syntax, and that expression is not legal. You
could do it with
a %$$% name
using the infix operator syntax. (I think the description in the R Language
Definition suggests this is not legal, since $$ is not a valid name, but it
does currently work and that's unlikely to change.)
Duncan Murdoch
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