Converted to C++ style randomization

The logic in rawr::randomSentence with the cuts might be slightly different now but who even knows what's going on there.

7 files changed, 86 insertions, 88 deletions

@@ -15,7 +15,7 @@ include_directories(
   ${ASPELL_INCLUDE_DIR}
   ${yaml-cpp_INCLUDE_DIRS})
 
-add_library(rawr kgramstats.cpp histogram.cpp prefix_search.cpp)
+add_library(rawr kgramstats.cpp prefix_search.cpp)
 set_property(TARGET rawr PROPERTY CXX_STANDARD 11)
 set_property(TARGET rawr PROPERTY CXX_STANDARD_REQUIRED ON)
 target_link_libraries(rawr ${ASPELL_LIBRARIES})
@@ -2,8 +2,6 @@
 #include <list>
 #include <map>
 #include "kgramstats.h"
-#include <ctime>
-#include <cstdlib>
 #include <fstream>
 #include <iostream>
 #include <twitter.h>
@@ -11,14 +9,15 @@
 #include <thread>
 #include <chrono>
 #include <algorithm>
+#include <random>
 
 const auto QUEUE_TIMEOUT = std::chrono::minutes(1);
 const auto POLL_TIMEOUT = std::chrono::minutes(5);
 
 int main(int argc, char** args)
 {
-  srand(time(NULL));
-  rand(); rand(); rand(); rand();
+  std::random_device randomDevice;
+  std::mt19937 rng(randomDevice());
 
   YAML::Node config = YAML::LoadFile("config.yml");
   int delay = config["delay"].as<int>();
@@ -72,7 +71,8 @@ int main(int argc, char** args)
     size_t pos = form.find("$name$");
     if (pos != std::string::npos)
     {
-      form.replace(pos, 6, fv_names[rand() % fv_names.size()]);
+      int fvInd = std::uniform_int_distribution<int>(0, fv_names.size()-1)(rng);
+      form.replace(pos, 6, fv_names[fvInd]);
     }
 
     return form;
@@ -92,12 +92,12 @@ int main(int argc, char** args)
 
     if (currentTime >= genTimer)
     {
-      std::string doc = kgramstats.randomSentence(140);
+      std::string doc = kgramstats.randomSentence(140, rng);
       doc.resize(140);
 
       postQueue.emplace_back(std::move(doc), false, 0);
 
-      int genwait = rand() % delay + 1;
+      int genwait = std::uniform_int_distribution<int>(1, delay)(rng);
 
       genTimer = currentTime + std::chrono::seconds(genwait);
     }
@@ -125,7 +125,7 @@ int main(int argc, char** args)
             && tweet.getAuthor() != client.getUser())
           {
             std::string doc = tweet.generateReplyPrefill(client.getUser());
-            doc += kgramstats.randomSentence(140 - doc.length());
+            doc += kgramstats.randomSentence(140 - doc.length(), rng);
             doc.resize(140);
 
             postQueue.emplace_back(std::move(doc), true, tweet.getID());
@@ -2,15 +2,15 @@
 #include <list>
 #include <map>
 #include "kgramstats.h"
-#include <ctime>
 #include <vector>
-#include <cstdlib>
 #include <fstream>
 #include <iostream>
+#include <random>
 
 int main(int argc, char** args)
 {
-  srand(time(NULL));
+  std::random_device randomDevice;
+  std::mt19937 rng(randomDevice());
     
   if (argc == 1)
   {
@@ -73,7 +73,8 @@ int main(int argc, char** args)
     size_t pos = form.find("$name$");
     if (pos != std::string::npos)
     {
-      form.replace(pos, 6, fv_names[rand() % fv_names.size()]);
+      int fvInd = std::uniform_int_distribution<int>(0, fv_names.size()-1)(rng);
+      form.replace(pos, 6, fv_names[fvInd]);
     }
     
     return form;
@@ -82,7 +83,7 @@ int main(int argc, char** args)
   std::cout << "Generating..." << std::endl;
   for (;;)
   {
-    std::string doc = kgramstats.randomSentence(140);
+    std::string doc = kgramstats.randomSentence(140, rng);
     doc.resize(140);
 
     std::cout << doc << std::endl;
@@ -1,46 +0,0 @@
-#include "histogram.h"
-#include "kgramstats.h"
-#include <cstdlib>
-#include <iostream>
-
-template <class T>
-void histogram<T>::add(const T& inst)
-{
-  freqtable[inst]++;
-}
-
-template <class T>
-void histogram<T>::compile()
-{
-  distribution.clear();
-  
-  int max = 0;
-  for (auto& it : freqtable)
-  {
-    max += it.second;
-    distribution.emplace(max, it.first);
-  }
-  
-  freqtable.clear();
-}
-
-template <class T>
-const T& histogram<T>::next() const
-{
-  int max = distribution.rbegin()->first;
-  int r = rand() % max;
-  
-  return distribution.upper_bound(r)->second;
-}
-
-template <class T>
-void histogram<T>::print() const
-{
-  for (auto& freqpair : freqtable)
-  {
-    std::cout << freqpair.first << ": " << freqpair.second << std::endl;
-  }
-}
-
-template class histogram <std::string>;
-template class histogram <rawr::terminator>;
@@ -3,18 +3,53 @@
 
 #include <map>
 #include <string>
+#include <random>
+#include <iostream>
 
 template <class T>
 class histogram {
-  public:
-    void add(const T& inst);
-    void compile();
-    const T& next() const;
-    void print() const;
-    
-  private:
-    std::map<T, int> freqtable;
-    std::map<int, T> distribution;
+public:
+
+  void add(const T& inst)
+  {
+    freqtable_[inst]++;
+  }
+
+  void compile()
+  {
+    distribution_.clear();
+
+    int max = 0;
+    for (auto& it : freqtable_)
+    {
+      max += it.second;
+      distribution_.emplace(max, it.first);
+    }
+
+    freqtable_.clear();
+  }
+
+  const T& next(std::mt19937& rng) const
+  {
+    int max = distribution_.rbegin()->first;
+    std::uniform_int_distribution<int> randDist(0, max - 1);
+    int r = randDist(rng);
+
+    return distribution_.upper_bound(r)->second;
+  }
+
+  void print() const
+  {
+    for (auto& freqpair : freqtable_)
+    {
+      std::cout << freqpair.first << ": " << freqpair.second << std::endl;
+    }
+  }
+
+private:
+
+  std::map<T, int> freqtable_;
+  std::map<int, T> distribution_;
 };
 
 #endif /* end of include guard: HISTOGRAM_H_24094D97 */
@@ -590,7 +590,7 @@ void rawr::setMinCorpora(int _arg)
 }
 
 // runs in O(n log t) time where n is the input number of sentences and t is the number of tokens in the input corpus
-std::string rawr::randomSentence(int maxL) const
+std::string rawr::randomSentence(int maxL, std::mt19937& rng) const
 {
   if (!_compiled)
   {
@@ -610,16 +610,13 @@ std::string rawr::randomSentence(int maxL) const
       cur.pop_front();
     }
     
-    do
+    while (cur.size() > 2 &&
+           cuts > 0 &&
+           !std::bernoulli_distribution(1.0 / static_cast<double>(cuts))(rng))
     {
-      if ((cur.size() > 2) && (cuts > 0) && ((rand() % cuts) > 0))
-      {
         cur.pop_front();
         cuts--;
-      } else {
-        break;
-      }
-    } while ((cur.size() > 2) && (cuts > 0) && ((rand() % cuts) > 0));
+    }
     
     // Gotta circumvent the last line of the input corpus
     // https://twitter.com/starla4444/status/684222271339237376
@@ -627,7 +624,8 @@ std::string rawr::randomSentence(int maxL) const
     {
       // The end of a corpus should probably be treated like a terminator, so
       // maybe we should just end here.
-      if ((result.length() > maxL) || (rand() % 4 == 0))
+      if (result.length() > maxL ||
+          std::bernoulli_distribution(1.0 / 4.0)(rng))
       {
         break;
       }
@@ -637,10 +635,11 @@ std::string rawr::randomSentence(int maxL) const
 
     auto& distribution = _stats.at(cur);
     int max = distribution.rbegin()->first;
-    int r = rand() % max;
+    std::uniform_int_distribution<int> randDist(0, max - 1);
+    int r = randDist(rng);
     const token_data& next = distribution.upper_bound(r)->second;
     const token& interned = _tokenstore.get(next.tok);
-    std::string nextToken = interned.w.forms.next();
+    std::string nextToken = interned.w.forms.next(rng);
 
     // Apply user-specified transforms
     if (_transform)
@@ -651,10 +650,16 @@ std::string rawr::randomSentence(int maxL) const
     // Determine the casing of the next token. We randomly make the token all
     // caps based on the markov chain. Otherwise, we check if the previous
     // token is the end of a sentence (terminating token or a wildcard query).
-    int casing = rand() % next.all;
+    std::uniform_int_distribution<int> caseDist(0, next.all - 1);
+    int casing = caseDist(rng);
+    
     if (casing < next.uppercase)
     {
-      std::transform(nextToken.begin(), nextToken.end(), nextToken.begin(), ::toupper);
+      std::transform(
+        std::begin(nextToken),
+        std::end(nextToken),
+        std::begin(nextToken),
+        ::toupper);
     } else {
       bool capitalize = false;
 
@@ -663,7 +668,7 @@ std::string rawr::randomSentence(int maxL) const
         capitalize = true;
       } else if (cur.rbegin()->type == querytype::sentence)
       {
-        if (rand() % 2 > 0)
+        if (std::bernoulli_distribution(1.0 / 2.0)(rng))
         {
           capitalize = true;
         }
@@ -671,7 +676,7 @@ std::string rawr::randomSentence(int maxL) const
         const token& lastTok = _tokenstore.get(cur.rbegin()->tok);
 
         if (lastTok.suffix == suffixtype::terminating &&
-            rand() % 2 > 0)
+            std::bernoulli_distribution(1.0 / 2.0)(rng))
         {
           capitalize = true;
         }
@@ -753,7 +758,7 @@ std::string rawr::randomSentence(int maxL) const
     // Terminators
     if (interned.suffix == suffixtype::terminating)
     {
-      auto term = interned.w.terms.next();
+      auto term = interned.w.terms.next(rng);
       nextToken.append(term.form);
       
       if (term.newline)
@@ -794,7 +799,9 @@ std::string rawr::randomSentence(int maxL) const
     cur.push_back(next.tok);
     result.append(nextToken);
 
-    if ((interned.suffix == suffixtype::terminating) && ((result.length() > maxL) || (rand() % 4 == 0)))
+    if (interned.suffix == suffixtype::terminating &&
+          (result.length() > maxL ||
+           std::bernoulli_distribution(1.0 / 4.0)(rng)))
     {
       break;
     }
@@ -803,7 +810,7 @@ std::string rawr::randomSentence(int maxL) const
   // Ensure that enough corpora are used
   if (used_corpora.size() < _min_corpora)
   {
-    return randomSentence(maxL);
+    return randomSentence(maxL, rng);
   }
   
   // Remove the trailing space
@@ -9,6 +9,7 @@
 #include "identifier.h"
 #include <functional>
 #include <set>
+#include <random>
 
 class rawr {
   public:
@@ -19,7 +20,7 @@ class rawr {
     
     void setTransformCallback(transform_callback _arg);
     void setMinCorpora(int _arg);
-        std::string randomSentence(int maxL) const;
+        std::string randomSentence(int maxL, std::mt19937& rng) const;
         
   private:
     struct terminator {