[Rcpp-devel] Testing for existence of named components

[Romain Francois]

Le 29/03/12 20:18, Dirk Eddelbuettel a écrit :
>
> On 29 March 2012 at 18:51, Patrick Burns wrote:
> | On 29/03/2012 18:33, Dirk Eddelbuettel wrote:
> |>
> |>  On 29 March 2012 at 19:12, Romain Francois wrote:
> |>  | Le 28/03/12 13:56, Ulrich Bodenhofer a écrit :
> |>  |>   Hi,
> |>  |>
> |>  |>   My question is the following: is there any way of checking in whether a
> |>  |>   component of an Rcpp list (or vector) with a given name exists in this
> |>  |>   list. If I simply try accessing a non-existing component, I get an
> |>  |>   "index out of bounds" error. Trying to catch a possible exception did
> |>  |>   not work either. I also browsed the Rcpp package source code, but
> |>  |>   unfortunately I got lost. Sorry if this has been addressed on this list
> |>  |>   before. At least I googled in many different ways, but could not find
> |>  |>   anything. Any ideas? Any help is gratefully appreciated!
> |>  |>
> |>  |>   Thanks and best regards,
> |>  |>   Ulrich
> |>  |
> |>  | Hello,
> |>  |
> |>  | I commited the has_element_called method on the Vector template (vectors
> |>  | of all sorts, incl lists).
> |>
> |>  +1, but how about just calling it 'contains' rather 'has_element_called' ?
> |
> | I think 'contains' would imply a value
> | in the vector rather than a name.  The
> | extra typing might be worth avoiding
> | that confusion.
>
> While that is true, it cannot deflect away from the fact that Hadley and I
> are in a deadly mano-a-mano battle about the extended use, or, in my case,
> strict avoidance, of underscores.  That is /extremely serious/ business.
>
> So how about hasElementCalled() then?
>
> Or given that these are 'names' how about
>
>     hasElementNamed()
>
> pr maybe
>
>     containsName()

Sure. Whatever makes anyone happy ;-)


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