pluralize.cpp

#include <string>

#define MAP(suffix, plural)                                             \
  if (singular.length() >= std::string(suffix).length()) {                              \
    if (singular.substr(singular.length() - std::string(suffix).length(), std::string(suffix).length()) == std::string(suffix)) { \
      return singular.substr(0, singular.length() - std::string(suffix).length()) + plural; \
    }                                                                   \
  }

/* NOTE: We assume all lower case! */
std::string pluralize(std::string singular) {
  /* Irregular */
  MAP("person", "people");
  MAP("man", "men");
  MAP("child", "children");
  MAP("sex", "sexes");
  MAP("move", "moves");
  MAP("cow", "kine");
  MAP("zombie", "zombies");

  /* Mappings */
  MAP("quiz", "quizzes");
  if (singular == "oxen") {
    return "oxen";
  }
  if (singular == "ox") {
    return "oxen";
  }
  MAP("mice", "mice");
  MAP("lice", "lice");
  MAP("mouse", "mice");
  MAP("louse", "lice");
  MAP("matrix", "matrices");
  MAP("vertix", "vertices");
  MAP("indix", "indices");
  MAP("matrex", "matrices");
  MAP("vertex", "vertices");
  MAP("index", "indices");
  MAP("x", "xes");
  MAP("ch", "ches");
  MAP("ss", "sses");
  MAP("sh", "shes");
  if (singular.length() >= 2) {
    if (singular.substr(singular.length() - 1, 1) == "y") {
      if (singular.substr(singular.length() - 2, 1) != "a" &&
          singular.substr(singular.length() - 2, 1) != "e" &&
          singular.substr(singular.length() - 2, 1) != "i" &&
          singular.substr(singular.length() - 2, 1) != "o" &&
          singular.substr(singular.length() - 2, 1) != "u" &&
          singular.substr(singular.length() - 2, 1) != "y") {
        return singular.substr(0, singular.length() - 1) + "ies";
      }
    }
  }
  MAP("quy", "quies");
  MAP("hive", "hives");
  if (singular.length() >= 3) {
    if (singular.substr(singular.length() - 2, 2) == "fe") {
      if (singular.substr(singular.length() - 2, 1) != "f") {
        return singular.substr(0, singular.length() - 2) + "ves";
      }
    }
  }
  MAP("lf", "lves");
  MAP("rf", "rves");
  MAP("sis", "ses");
  MAP("ta", "ta");
  MAP("ia", "ia");
  MAP("tum", "ta");
  MAP("ium", "ia");
  MAP("buffalo", "buffaloes");
  MAP("tomato", "tomatoes");
  MAP("bus", "buses");
  MAP("alias", "aliases");
  MAP("status", "statuses");
  MAP("octopi", "octopii");
  MAP("viri", "virii");
  MAP("octopus", "octopuses");
  MAP("virus", "viruses");
  MAP("axis", "axes");
  MAP("testis", "testes");
  MAP("s", "s");
  return singular + "s";
}