anchor.diff:  library trainer;
  +
  +import 'dart:html';
  +import 'dart:convert';
   
   
   class Trainer{
  
positive.code:     return 100 - (_errors.toDouble() / sofar.length.toDouble() * 100).round();
  
    }
  }
negative.code:   Trainer(this.targettext);
    
    int get currentposition => _currentposition;
    set currentposition(int n) => _currentposition = n;
    
    int currentposforward() => _currentposition++;
    
    int currentposbackward()=> _currentposition--;
  
    String charAtPosition() => targettext.split('')[_currentposition];
    
    set errors(int n) => _errors = n;
    
  