R devel - Apr 2019 - Parsing code with newlines

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

Hello!

This is my first post here. I came across the very same problem.
It can be reproduced within modified tests/Embedding/RParseEval.c

Actually this example has another issue, namely it doesn't wrap
everything in R_ToplevelExec . This is a major show stopper for
newcomers as that function is barely mentioned anywhere and longjmp into
terminated setuploop function followed by R_suicide look like a mystery.

Error: bad value
Fatal error: unable to initialize the JIT


That aside, here is the code with newlines that fails to parse. I hope
it will paste alright here.


#include "embeddedRCall.h"
#include <R_ext/Parse.h>

int
main(int argc, char *argv[])
{
    SEXP e, tmp;
    int hadError;
    ParseStatus status;

    init_R(argc, argv);

    PROTECT(tmp = mkString("\n\r ls()"));
    PROTECT(e = R_ParseVector(tmp, 1, &status, R_NilValue));
    if (status != PARSE_OK)
    {
        printf("boo boo\n");
    }
    else
    {
        PrintValue(e);
        R_tryEval(VECTOR_ELT(e,0), R_GlobalEnv, &hadError);
    }
    UNPROTECT(2);

    end_R();
    return(0);
}


--
Mikhail