/// <summary>
/// Executes the interpreter.
/// </summary>
public void Execute()
{
bool quit = false;
while (!quit)
{
_teletypeWithPosition.NewLine();
_teletypeWithPosition.Write(">");
var command = _teletypeWithPosition.Read();
if (command == null)
{
_runEnvironment.KeyboardBreak = false;
continue;
}
try
{
var parsedLine = _tokeniser.Tokenise(command);
if (parsedLine.LineNumber.HasValue)
{
_programRepository.SetProgramLine(parsedLine);
}
else
{
_runEnvironment.CurrentLine = parsedLine;
quit = _executor.ExecuteLine();
}
}
catch (Exceptions.BreakException endError)
{
if (endError.ErrorMessage != string.Empty)
{
WriteErrorToTeletype(
_runEnvironment.CurrentLine.LineNumber,
endError.ErrorMessage);
}
}
catch (Exceptions.BasicException basicError)
{
WriteErrorToTeletype(
_runEnvironment.DataErrorLine ?? _runEnvironment.CurrentLine?.LineNumber,
"?" + basicError.ErrorMessage + " ERROR");
}
}
}
/// <summary>
/// Executes the PRINT command.
/// </summary>
public void Execute()
{
bool newLine = true;
while (true)
{
var token = _runEnvironment.CurrentLine.NextToken();
if ((token.Seperator == TokenType.Colon) ||
(token.Statement == TokenType.Else) ||
(token.Seperator == TokenType.EndOfLine))
{
if (newLine)
{
_teletype.NewLine();
}
_runEnvironment.CurrentLine.PushToken(token);
return;
}
if ((token.Statement == TokenType.Tab) || (token.Statement == TokenType.Space))
{
short value = _expressionEvaluator.GetExpression().ValueAsShort();
if (_runEnvironment.CurrentLine.NextToken().Seperator != TokenType.CloseBracket)
{
throw new Exceptions.SyntaxErrorException();
}
if (token.Statement == TokenType.Tab)
{
_teletype.Tab(value);
}
else
{
_teletype.Space(value);
}
}
else if ((token.Seperator == TokenType.Semicolon) || (token.Seperator == TokenType.Comma))
{
newLine = false;
if (token.Seperator == TokenType.Comma)
{
_teletype.NextComma();
}
}
else
{
newLine = true;
_runEnvironment.CurrentLine.PushToken(token);
_teletype.Write(_expressionEvaluator.GetExpression().ToString());
}
}
}
public void TeletypeWithPositionWritesEnvironmentNewLine()
{
_mockTeletype = new Mock <ITeletype>();
_mockTeletype.Setup(mt => mt.Width).Returns(80);
_sut = new TeletypeWithPosition(_mockTeletype.Object);
_sut.NewLine();
_mockTeletype.Verify(mt => mt.Write(Environment.NewLine), Times.Once);
Assert.AreEqual(1, _sut.Position());
}
