[Rd] suggestion of new API function for embedded programming.

[Luke Tierney]

On Wed, 3 Sep 2008, EBo wrote:

>
> While doing some embedded programming and trying to figure out how to generate
> a hand coded SEXP equivalent of the line
> "t.test(x,conf.level=(1-p))$conf.int[2]" I had an idea for an addition to the
> embedded API.
>
> There are a number of hidden or static parse functions (R_ParseBuffer,
> R_Parse1Buffer, etc.) which take an IoBuffer* and returns a parsed tree.  If
> one or more of these functions were exported to the Rembedded.h API we could
> do something like the following:
>
>  R_Expr = R_Parse1Buffer(&R_ConsoleIob, 0, &status);
>  if (PARSE_OK==status) {
>    ...
>    value = eval(R_CurrentExpr, rho);
>    ...
>  }

We definitely do NOT want this frozen into the public API.

>
> or possibly simplifying the interface to take the CMDL string:
>
>  R_Expr = R_Parse1Line("t.test(x,conf.level=(1-p))$conf.int[2]", &status);
>
> I think this would be a useful addition to the embedding interface, and
> hopefully not difficult to incorporate by someone more experienced with the
> internals than I currently am.  I took a few hours to look into adding this
> interface, but will not have time to try to do so for a few months -- I have a
> couple of hard and fast deadlines over the next couple of weeks.  So, I would
> like to make the suggestion and participate in the dialog.

Something along these lines should be feasible in principle, though
care may be needed in handlign of errors.

luke

>
>  Best regards,
>
>  EBo --
>
> ps: if someone can suggest how to hand code
> "t.test(x,conf.level=(1-p))$conf.int[2]" so I can embedd it I would be most
> appreciative.
>
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>

-- 
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:      luke at stat.uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu