Rf_ScalarLogical

Converts an int x to a SEXP object that represents an R length one logical vector. The mapping from C integers to R's logical is:

• If x is NA_LOGICAL, then return value is NA (R_LogicalNAValue)

• If x is 0, then return value is FALSE (R_FalseValue)

• If x is any other value, then the return value is TRUE (R_TrueValue)

Arguments

x	an int value.

Value

A SEXP object, namely a length one logical vector.

Declaration

SEXP Rf_ScalarLogical(int x);

In Rinternals.h.

Definition

INLINE_FUN SEXP ScalarLogical(int x)
{
  extern SEXP R_LogicalNAValue, R_TrueValue, R_FalseValue;
  if (x == NA_LOGICAL) return R_LogicalNAValue;
  else if (x != 0) return R_TrueValue;
  else return R_FalseValue;
}

In Rinlinedfuns.h.

Examples

# Convert a C int number as an R length one logical vector with TRUE
true <- inline::cfunction(NULL,
 ' int x = 2;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ' int x = 2;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ')
true()
#> [1] TRUE

# Convert a C int number as an R length one logical vector with FALSE
false <- inline::cfunction(NULL,
 ' int x = 0;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ' int x = 0;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ')
false()
#> [1] FALSE

# Convert a C int number as an R length one logical vector with NA
na_logical <- inline::cfunction(NULL,
 ' int x = NA_LOGICAL;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ' int x = NA_LOGICAL;
   SEXP y;
   y = PROTECT(Rf_ScalarLogical(x));
   UNPROTECT(1);
   return y;
 ')
na_logical()
#> [1] NA