Dear Rusers, when i am reading Rinternals.h file, i can't understand the following codes in lines 395-407:
#define CHAR(x)R_CHAR(x) const char *(R_CHAR)(SEXP x); /* Various tests with macro versions below */ Rboolean (Rf_isNull)(SEXP s); Rboolean (Rf_isSymbol)(SEXP s); Rboolean (Rf_isLogical)(SEXP s); Rboolean (Rf_isReal)(SEXP s); Rboolean (Rf_isComplex)(SEXP s); Rboolean (Rf_isExpression)(SEXP s); Rboolean (Rf_isEnvironment)(SEXP s); Rboolean (Rf_isString)(SEXP s); Rboolean (Rf_isObject)(SEXP s); I can't figure out what are "R_CHAR,Rf_isNull....Rf_isObject" meaning, they seem like function declarations, Rf_XXX maybe function pointers? I need your help. -- PO SU mail: desolato...@163.com Majored in Statistics from SJTU [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.