Added C++ std::map based HashTable module.

DESCRIPTION

@@ -19,8 +19,9 @@ Depends:
     tensorA,
     assertthat
 Imports:
+    methods,
+    Rcpp (>= 1.0.4),
     gtools,
-    fastmap,
     R6,
     cluster,
     stats,
@@ -28,7 +29,9 @@ Imports:
     SPIn,
     grDevices,
     reshape2
-RoxygenNote: 6.0.1
+LinkingTo: Rcpp
+DynLib: sourceR
+RoxygenNote: 7.1.0
 KeepSource: TRUE
 LazyData: TRUE
 Suggests:

NAMESPACE

@@ -24,3 +24,4 @@ importFrom(SPIn,SPIn)
 importFrom(grDevices,col2rgb)
 importFrom(grDevices,colorRampPalette)
 importFrom(stats,median)
+useDynLib(sourceR)

R/HashTable.R

+HashTable = function(keys=character(0), vals=numeric(0)) {
+  new("Rcpp_HashTable", keys, vals)
+}

R/sourceR.R

@@ -7,4 +7,5 @@
 #' The main sourceR method is \code{\link{HaldDP}}.
 #' @docType package
 #' @name sourceR
+#' @useDynLib sourceR
 NULL

R/zzz.R

+Rcpp::loadModule("HashTable_module")

src/HashTable.cpp

+#include <Rcpp.h>
+#include <iostream>
+#include <string>
+#include <map>
+
+using namespace Rcpp;
+//[[Rcpp::plugins(cpp11)]]
+
+class HashTable {
+public:
+  HashTable(SEXP key, SEXP val)
+  {
+    CharacterVector key_(key);
+    NumericVector val_(val);
+    insert(key_, val_);
+  }
+
+  void insert(CharacterVector key, NumericVector val)
+  {
+    if (key.size() != val.size())
+      throw Rcpp::exception("length(keys) must match length(val)");
+    CharacterVector::iterator k;
+    NumericVector::iterator v;
+    for(k=key.begin(), v=val.begin();
+        k!=key.end(); ++k, ++v) {
+      std::string key_str = std::string(*k);
+      ht_[key_str] = *v;
+    }
+  }
+
+  NumericVector find(CharacterVector keys) const
+  {
+    NumericVector rv;
+    for (auto k = keys.begin(); k != keys.end(); ++k)
+    {
+      auto val = ht_.find(std::string(*k));
+      if (val != ht_.end())
+        rv.push_back(val->second);
+      else
+        rv.push_back(NA_REAL);
+    }
+    return rv;
+  }
+
+  void erase(CharacterVector keys)
+  {
+    for (auto k = keys.begin(); k != keys.end(); ++k)
+    {
+      auto it = ht_.find(std::string(*k));
+      if (it != ht_.end())
+        ht_.erase(it);
+      else
+        throw Rcpp::exception("no such key in hashtable");
+    }
+  }
+
+  NumericVector values() const
+  {
+    NumericVector vals;
+    for (auto it = ht_.begin(); it!=ht_.end(); ++it)
+      vals.push_back(it->second);
+    return vals;
+  }
+
+  CharacterVector keys() const
+  {
+    CharacterVector keys;
+    for(auto it = ht_.begin(); it!=ht_.end(); ++it)
+      keys.push_back(it->first);
+    return keys;
+  }
+
+  void print() const
+  {
+    for(auto it = ht_.begin(); it!=ht_.end(); ++it)
+      Rcout << it->first << ": " << it->second << "\n";
+    Rcout << std::flush;
+  }
+
+private:
+  typedef std::map<std::string, double> HashTable_t;
+  HashTable_t ht_;
+};
+
+
+/* hashtable is a lightweight wrapper around C++ std::map
+ * for creating a hash table of character => numeric pairs.
+ */
+RCPP_MODULE(HashTable_module)
+{
+  class_<HashTable>("HashTable")
+
+  .constructor<SEXP, SEXP>()
+
+  .method("find", &HashTable::find)
+  .method("insert", &HashTable::insert)
+  .method("erase", &HashTable::erase)
+  .method("keys", &HashTable::keys)
+  .method("values", &HashTable::values)
+  .method("print", &HashTable::print)
+  ;
+}

src/RcppExports.cpp

+// Generated by using Rcpp::compileAttributes() -> do not edit by hand
+// Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393
+
+#include <Rcpp.h>
+
+using namespace Rcpp;
+
+
+RcppExport SEXP _rcpp_module_boot_HashTable_module();
+
+static const R_CallMethodDef CallEntries[] = {
+    {"_rcpp_module_boot_HashTable_module", (DL_FUNC) &_rcpp_module_boot_HashTable_module, 0},
+    {NULL, NULL, 0}
+};
+
+RcppExport void R_init_sourceR(DllInfo *dll) {
+    R_registerRoutines(dll, NULL, CallEntries, NULL, NULL);
+    R_useDynamicSymbols(dll, FALSE);
+}

tests/testthat/testHashTable.R

+context("HashTable")
+
+test_that("HashTable setup", {
+  keys = as.character(1:4)
+  vals = 1:4/10
+  ht = HashTable(keys, vals)
+  expect_equal(ht$keys(), keys)
+  expect_equal(ht$values(), vals)
+})
+
+test_that("HashTable insert", {
+  keys = as.character(1:4)
+  vals = 1:4/10
+  ht = HashTable(keys, vals)
+  ht$insert("5", 0.5)
+  expect_equal(ht$keys(), c(keys, "5"))
+  expect_equal(ht$values(), c(vals, 0.5))
+})
+
+test_that("HashTable erase", {
+  keys = as.character(1:4)
+  vals = 1:4/10
+  ht = HashTable(keys, vals)
+  ht$erase("1")
+  expect_equal(ht$keys(), keys[-1])
+  expect_equal(ht$values(), vals[-1])
+})