[Rd] Parsing code with newlines

Prof Brian Ripley ripley at stats.ox.ac.uk
Mon Aug 4 15:18:52 CEST 2008


This adds nothing to your previous post: please don't be annoying and post 
almost identical messages.

I strongly suspect you mean 'parse error' and 'how can I parse R code', 
but we don't know what the example was and what the error message was. 
Nor do we know what you are doing with this fragement of C code (and 
returnng an unprotected SEXP via a (void *) cast is a recipe for tears).

parse(text=) uses R_ParseVector, and that works for 'code that includes 
comments and newlines', so please check out the internal code used (in 
src/main/gram.c).

If you study the posting guide you should be able to formulate a posting 
that people can actually help you with.

On Mon, 4 Aug 2008, Peter Jaeger wrote:

> Dear List,
>
> When I try to parse code containing newline characters with R_ParseVector, I
> get a compilation error. How can I compile code that includes comments and
> newlines?
>
> I am using the following:
>
> void* my_compile(char *code)
> {
>    SEXP cmdSexp, cmdExpr = R_NilValue;
>    ParseStatus status;
>
>    PROTECT (cmdSexp = allocVector (STRSXP, 1));
>    SET_STRING_ELT (cmdSexp, 0, mkChar (code));
>    PROTECT (cmdExpr = R_ParseVector (cmdSexp,-1,&status,
>        R_NilValue));
>    UNPROTECT_PTR (cmdSexp);
>
>    if (status != PARSE_OK) {
>        return (void*)0;
>    } else {
>        return (void*)cmdExpr;
>    }
> }
>
> Regards,
> Peter
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



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