cppvader

This is a single-header C++ port of the Valence Aware Dictionary and sEntiment Reasoner (VADER) sentiment analysis tool, written in Python.

Note that the code of this implementation follows that of the original fairly closely. This means that it does not necessarily conform to established best practices of C++ development. It could use a fair amount of restructuring and optimisation.

However, at this point it is usable in your projects.

Progress

2021-05-04

All tests now pass.

Minimal working example

#include "include/cppvader.hpp"

int main()
{
  vader::SentimentIntensityAnalyser analyser;
  const std::vector<std::string> sentences = 
  {
    "VADER is smart, handsome, and funny.", // positive sentence example
    "VADER is smart, handsome, and funny!", // punctuation emphasis handled correctly (sentiment intensity adjusted)
    "VADER is very smart, handsome, and funny.",  // booster words handled correctly (sentiment intensity adjusted)
    "VADER is VERY SMART, handsome, and FUNNY.",   // emphasis for ALLCAPS handled
    "VADER is VERY SMART, handsome, and FUNNY!!!",  // combination of signals - VADER appropriately adjusts intensity
    "VADER is VERY SMART, uber handsome, and FRIGGIN FUNNY!!!",  // booster words & punctuation make this close to ceiling for score
    "VADER is not smart, handsome, nor funny.",  // negation sentence example
    "The book was good.",  // positive sentence
    "At least it isn't a horrible book.",  // negated negative sentence with contraction
    "The book was only kind of good.",  // qualified positive sentence is handled correctly (intensity adjusted)
    "The plot was good, but the characters are uncompelling and the dialog is not great.",  // mixed negation sentence
    "Today SUX!",  // negative slang with capitalization emphasis
    "Today only kinda sux! But I'll get by, lol",  // mixed sentiment example with slang and constrastive conjunction "but"
    "Make sure you :) or :D today!",  // emoticons handled
    "Catch utf-8 emoji such as 💘 and 💋 and 😁",  // emojis handled
    "Not bad at all"  // Capitalized negation
  };

  for (auto &sentence : sentences)
  {
    std::cout.width(80);
    std::cout << sentence << "\t\t" << std::right << analyser.polarityScores(sentence);
  }
}

Output:

                                              VADER is smart, handsome, and funny.    {neg: 0, neu: 0.2542, pos: 0.7458, compound: 0.8316}
                                              VADER is smart, handsome, and funny!    {neg: 0, neu: 0.2481, pos: 0.7519, compound: 0.8439}
                                         VADER is very smart, handsome, and funny.    {neg: 0, neu: 0.2991, pos: 0.7009, compound: 0.8545}
                                         VADER is VERY SMART, handsome, and FUNNY.    {neg: 0, neu: 0.2459, pos: 0.7541, compound: 0.9227}
                                       VADER is VERY SMART, handsome, and FUNNY!!!    {neg: 0, neu: 0.2333, pos: 0.7667, compound: 0.9342}
                          VADER is VERY SMART, uber handsome, and FRIGGIN FUNNY!!!    {neg: 0, neu: 0.294, pos: 0.706, compound: 0.9469}
                                          VADER is not smart, handsome, nor funny.    {neg: 0.6458, neu: 0.3542, pos: 0, compound: -0.7424}
                                                                The book was good.    {neg: 0, neu: 0.5085, pos: 0.4915, compound: 0.4404}
                                                At least it isn't a horrible book.    {neg: 0, neu: 0.678, pos: 0.322, compound: 0.431}
                                                   The book was only kind of good.    {neg: 0, neu: 0.6971, pos: 0.3029, compound: 0.3832}
The plot was good, but the characters are uncompelling and the dialog is not great.   {neg: 0.3274, neu: 0.5786, pos: 0.09402, compound: -0.7042}
                                                                        Today SUX!    {neg: 0.779, neu: 0.221, pos: 0, compound: -0.5461}
                                        Today only kinda sux! But I'll get by, lol    {neg: 0.1273, neu: 0.5558, pos: 0.3169, compound: 0.5249}
                                                     Make sure you :) or :D today!    {neg: 0, neu: 0.2936, pos: 0.7064, compound: 0.8633}
                                       Catch utf-8 emoji such as 💘 and 💋 and 😁    {neg: 0, neu: 0.5833, pos: 0.4167, compound: 0.875}
                                                                    Not bad at all    {neg: 0, neu: 0.5128, pos: 0.4872, compound: 0.431}