Missing Rcpp Strings support

[FabrizioSandri]

Description

RcppDeepState supports the analysis of functions that contain arguments which type falls in the following list:

• Rcpp::NumericVector
• Rcpp::NumericMatrix
• Rcpp::CharacterVector
• Rcpp::IntegerVector
• arma::mat
• std::double
• std::string
• std::int

However I found that if a function contains a Rcpp::String argument, the function will no be analyzed. It will be a good step to implement this lack and add the support for Rcpp::String arguments. RcppDeepState now only accepts std::string arguments, not Rcpp::String.

@tdhock I plan to solve this in a new pull request.

Steps to reproduce

I created a simple Rcpp based package containing the getLen function that calculates the length of a Rcpp::String.

#include <Rcpp.h>
#include <string>

using namespace std;

// [[Rcpp::export]]
int getLen(Rcpp::String arg1){
    return(strlen(arg1.get_cstr()));
}

However, if I attempt to compile this package using RcppDeepState, an error is thrown.
The Rcpp::String argument is not supported, which is the reason for this.

> require("RcppDeepState")
> deepstate_harness_compile_run("/home/fabri/test/testHarness/Rcpp/getLen", verbose=TRUE)
...

We can't test the function - getLen - due to the following datatypes falling out of the allowed ones: String

Error in deepstate_pkg_create(package_path, verbose) : 
  Testharnesses cannot be created for the package - datatypes fall out of specified list!!

[tdhock]

sure that is reasonable.
the reason why we prioritized std::string is that it is frequently used. here is a table of frequency of top 100 Rcpp types in CRAN packages, from code https://github.com/NAU-CS/RcppExports/blob/master/compileAttributes-parse.R

> arg.dt[, .(usages=.N), by=clean.type][order(-usages)][1:100]
                                   clean.type usages
                                       <char>  <int>
  1:                                      int  10610
  2:                                   double  10460
  3:                      Rcpp::NumericVector   9374
  4:                                arma::mat   5317
  5:                                arma::vec   4620
  6:                      Rcpp::NumericMatrix   4062
  7:                                     bool   4058
  8:                                     SEXP   3826
  9:                               Rcpp::List   2624
 10:                      Rcpp::IntegerVector   2226
 11:                              std::string   2109
 12:                             unsigned int   1093
 13:                    Rcpp::CharacterVector    971
 14:                      Rcpp::IntegerMatrix    541
 15:                      std::vector<double>    509
 16:                          Eigen::VectorXd    491
 17:                          Rcpp::DataFrame    439
 18:                             arma::colvec    427
 19:                               arma::uvec    416
 20:                          Eigen::MatrixXd    415
 21:                                     long    400
 22:                 std::vector<std::string>    394
 23:                            Rcpp::RObject    282
 24:                             Rcpp::String    280
 25:                              std::size_t    276
 26:                         std::vector<int>    258
 27:                               arma::cube    257
 28:                           Rcpp::Function    249
 29:                              arma::uword    247
 30:                      Rcpp::LogicalVector    227
 31:              Eigen::Map<Eigen::MatrixXd>    209
 32:                               arma::ivec    202
 33:                                    float    165
 34:                                 Rcpp::S4    159
 35:                             arma::sp_mat    151
 36:                          Eigen::VectorXi    150
 37:      Rcpp::Nullable<Rcpp::NumericVector>    148
 38:                       Rcpp::StringVector    141
 39:                                 unsigned    124
 40:                        Rcpp::Environment    121
 41:                             arma::rowvec    114
 42:                                XPtrImage     99
 43:              Eigen::Map<Eigen::VectorXd>     96
 44:              Eigen::SparseMatrix<double>     83
 45:                               arma::umat     77
 46:                                     char     65
 47:                       Rcpp::DoubleVector     63
 48:                                   uint64     62
 49:                   arma::field<arma::vec>     59
 50:                                    char*     57
 51:                                     uint     53
 52:                      Rcpp::LogicalMatrix     51
 53: Eigen::Matrix<double, Eigen::Dynamic, 1>     50
 54:                          Rcpp::RawVector     49
 55:                        std::vector<long>     49
 56:                                   char *     48
 57:                             arma::cx_mat     43
 58:                        arma::Mat<double>     41
 59:                      Rcpp::XPtr<matrix4>     39
 60:                                 XPtrNode     38
 61:                   arma::field<arma::mat>     37
 62:                           Eigen::ArrayXd     36
 63:              std::vector<QuantLib::Date>     34
 64:                               arma::imat     34
 65:                                       CV     33
 66:                    Rcpp::CharacterMatrix     31
 67:                              PyObjectRef     31
 68:                              arma::ucube     27
 69:                      arma::Col<unsigned>     26
 70:                   std::vector<arma::mat>     25
 71:                            arma::cx_cube     25
 72:   arma::field<arma::Cube<unsigned char>>     24
 73:                           arma::Col<int>     23
 74:                                 uint32_t     23
 75:                           QuantLib::Date     23
 76:                      Rcpp::GenericVector     23
 77:                          Rcpp::RawMatrix     22
 78:                std::vector<unsigned int>     21
 79:              Rcpp::Nullable<std::string>     21
 80:                                  XPtrMat     21
 81:                                  XPtrDoc     20
 82:      Rcpp::Nullable<Rcpp::IntegerVector>     19
 83:      Rcpp::Nullable<Rcpp::NumericMatrix>     18
 84:                                DbResult*     18
 85:                            unsigned long     17
 86:    std::vector<std::vector<std::string>>     17
 87:               Eigen::Map<Eigen::ArrayXd>     16
 88:              Rcpp::XPtr<DbConnectionPtr>     16
 89:                         Rcpp::DateVector     16
 90:                          RcppGSL::Matrix     16
 91:                 std::vector<std::size_t>     16
 92:           std::vector<Rcpp::Environment>     16
 93:                            ComplexVector     15
 94:                            std::ostream*     15
 95:            std::vector<std::vector<int>>     14
 96:                        std::vector<bool>     14
 97:    Rcpp::Nullable<Rcpp::CharacterVector>     14
 98:         std::vector<std::vector<double>>     13
 99:                             arma::cx_vec     13
100:                                   Symbol     13
                                   clean.type usages 

[FabrizioSandri]

Thanks for sharing this with me @tdhock . This a really useful ranking.

Would it be useful to build new functions to generate data for more datatypes in this list later (perhaps during the second coding period) in order to increase RcppDeepState's coverage?

[tdhock]

yes that could be a secondary goal later on. I think we should first focus on getting a basic github action working.