[Rcpp-devel] Testing for existence of named components

[Dirk Eddelbuettel]

On 29 March 2012 at 20:59, Romain Francois wrote:
| 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 ;-)

Ok, so barring objections, I'll change the code as well as the unit test I
added to use 'hasElementNamed()'.

Dirk

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