The data types of input and output parameters of R FNC functions conform to typical usage of R data types. However, R FNC functions are implemented using existing C FNC functions. Therefore, wrappers are used to convert data from R data types to C data types and vice versa. The mapping between R and C data types is shown in the following table.
| R | C |
|---|---|
| integer |
|
| real |
|
| character | char, when used for characters and strings |
| raw |
|
| vector | array |
| list | struct |