[Rd] WRE about R_strtod
Kurt Hornik
Kurt@Horn|k @end|ng |rom wu@@c@@t
Thu Oct 10 11:04:26 CEST 2024
>>>>> Ivan Krylov via R-devel writes:
Thanks: changed now.
Best
-k
> Hello,
> This is what "Writing R extensions" currently says about R_atof and
> R_strtod:
>>> Function: void R_atof (const char* str)
>>> Function: void R_strtod (const char* str, char ** end)
>>>
>>> Implementations of the C99/POSIX functions atof and strtod which
>>> guarantee platform-dependent behaviour, including always using the
>>> period as the decimal point aka ‘radix character’ and converting
>>> "NA" to R’s NA_REAL_ .
> Besides the easily fixable return type (void -> double), shouldn't the
> documentation mention the fact that, unlike the standard C library
> functions, R's parser returns NA_REAL instead of 0 when no conversion
> is performed (including for the "NA" string, *end == str)?
> Index: doc/manual/R-exts.texi
> ===================================================================
> --- doc/manual/R-exts.texi (revision 87211)
> +++ doc/manual/R-exts.texi (working copy)
> @@ -16482,12 +16482,12 @@
> @apifun R_atof
> @apifun R_strtod
> - using deftypefun void R_atof (const char* @var{str})
> - using deftypefunx void R_strtod (const char* @var{str}, char ** @var{end})
> + using deftypefun double R_atof (const char* @var{str})
> + using deftypefunx double R_strtod (const char* @var{str}, char ** @var{end})
> Implementations of the C99/POSIX functions @code{atof} and @code{strtod}
> which guarantee platform-dependent behaviour, including always using the
> -period as the decimal point @emph{aka} `@I{radix character}' and converting
> - using code{"NA"} to R's @code{NA_REAL_} .
> +period as the decimal point @emph{aka} `@I{radix character}' and returning
> +R's @code{NA_REAL_} for all unconverted strings, including @code{"NA"}.
> @end deftypefun
> --
> Best regards,
> Ivan
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