textEditor.cpp

#include <string>
#include <string_view>
#include "test_runner.h"
#include "math.h"
using namespace std;

class Editor {
 public:
  // Реализуйте конструктор по умолчанию и объявленные методы
  Editor(){
      str = "";
      point = str.begin();
      buffer = "";
  }
  void Left(){
      if(point!=str.begin()){
          point-=1;
      }
  }
  void Right(){
      if(point!=str.end()){
          point++;
      }
  }
  void Insert(char token){
      str.insert(point,token);
      Right();
  }
  void Cut(size_t tokens = 1){
      Copy(tokens);
      str.erase(point,point+min(tokens,size_t(str.end()-point)));
  }
  void Copy(size_t tokens = 1){
      buffer = str.substr(point - str.begin(),min(tokens,size_t(str.end()-point)));
  }
  void Paste(){
      str.insert(point,buffer.begin(),buffer.end());
      point += buffer.length();
  }
  string GetText() const{
      return str;
  }
 private:
  string str;
  string::iterator point;
  string buffer;
};

void TypeText(Editor& editor, const string& text) {
  for(char c : text) {
    editor.Insert(c);
  }
}

void TestEditing() {
  {
    Editor editor;

    const size_t text_len = 12;
    const size_t first_part_len = 7;
    TypeText(editor, "hello, world");
    for(size_t i = 0; i < text_len; ++i) {
      editor.Left();
    }
    editor.Cut(first_part_len);
    for(size_t i = 0; i < text_len - first_part_len; ++i) {
      editor.Right();
    }
    TypeText(editor, ", ");
    editor.Paste();
    editor.Left();
    editor.Left();
    editor.Cut(3);

    ASSERT_EQUAL(editor.GetText(), "world, hello");
  }
  {
    Editor editor;

    TypeText(editor, "misprnit");
    editor.Left();
    editor.Left();
    editor.Left();
    editor.Cut(1);
    editor.Right();
    editor.Paste();

    ASSERT_EQUAL(editor.GetText(), "misprint");
  }
}

void TestReverse() {
  Editor editor;

  const string text = "esreveR";
  for(char c : text) {
    editor.Insert(c);
    editor.Left();
  }

  ASSERT_EQUAL(editor.GetText(), "Reverse");
}

void TestNoText() {
  Editor editor;
  ASSERT_EQUAL(editor.GetText(), "");

  editor.Left();
  editor.Left();
  editor.Right();
  editor.Right();
  editor.Copy(0);
  editor.Cut(0);
  editor.Paste();

  ASSERT_EQUAL(editor.GetText(), "");
}

void TestEmptyBuffer() {
  Editor editor;

  editor.Paste();
  TypeText(editor, "example");
  editor.Left();
  editor.Left();
  editor.Paste();
  editor.Right();
  editor.Paste();
  editor.Copy(0);
  editor.Paste();
  editor.Left();
  editor.Cut(0);
  editor.Paste();

  ASSERT_EQUAL(editor.GetText(), "example");
}

int main() {
  TestRunner tr;
  RUN_TEST(tr, TestEditing);
  RUN_TEST(tr, TestReverse);
  RUN_TEST(tr, TestNoText);
  RUN_TEST(tr, TestEmptyBuffer);
  return 0;
}