anchor.diff:  }
   
   /// Contains a single instruction that was generated for a portion of the AST.
  -/// It can be executed on a [VM].
  +/// It can be executed by a [VM].
   class Instruction {
     /// These tokens are taken from the AST nodes that produced this instruction.
     /// For example, for an [AddInstruction], `tokens` will reference a `+` token.
  
positive.code: 
    /// Read [memory] at address as the specified number type.
    num readMemoryValue(int address, NumberType numberType) {
      return memory.getValue(address, numberType);
    }
  
    /// Read [memory] at the current stack pointer as the specified number type,
  
negative.code:   /// Insert value into [memory] at the specified address, encoded as the
    /// specified number type.
    void setMemoryValue(int address, NumberType numberType, num value) {
      if (address < codeSegmentSize)
        throw new SegfaultSignal(address, 'The code segment is read-only');
      try {
        memory.setValue(address, numberType, value);
      } on RangeError {
        throw new SegfaultSignal(address, 'Out of range');
      }
    }
  
    /// Encode value as the specified number type, increase the stack pointer by
  