/// <summary>
/// Run Statement
/// </summary>
/// <param name="BasicIntrepeter">Basic Intrepeter that called the Statement</param>
public override void ExcecuteStatement(Basic BasicIntrepeter)
{
bool openParenthis = false;
bool MultiLineIF = false;
double ComparisonResult;
BasicIntrepeter.CodeParser.Expect(typeof(IfToken));
// Alow the usage of parenthis like C language
if (typeof(LeftParenToken).Equals(BasicIntrepeter.CodeParser.CurrentToken.GetType()))
{
BasicIntrepeter.CodeParser.Expect(typeof(LeftParenToken));
openParenthis = true;
}
// Get comparison result
ComparisonResult = BasicIntrepeter.NumericModifier.ExpressionLevel3();
// If we had an opening parenthis we expect a closing one
if (openParenthis)
BasicIntrepeter.CodeParser.Expect(typeof(RightParenToken));
// Expect THEN
Parser.Expect(typeof(ThenToken));
// Check if multiline
if (Parser.CurrentToken.GetType().Equals(typeof(EndOfLineToken)))
{
MultiLineIF = true;
BasicIntrepeter.CodeParser.Next();
}
if (MultiLineIF)
{
///////////////////////////////////////////////////////////////////
//
// MULTILINE IF
//
///////////////////////////////////////////////////////////////////
if (ComparisonResult >= 1)
{
// 1. Excecute Statements until ENDIF or ELSE
// ------------------------------------------------------------
while (true)
{
if (
(BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))) ||
(BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken))) ||
(BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
break;
// If NewLine skip it.
// So we can be sure that all ELSE and ENDIF tokens are catched!
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfLineToken)))
{
BasicIntrepeter.CodeParser.Next();
continue;
}
if (!BasicIntrepeter.DontExectuteIF) BasicIntrepeter.ProcessNextStatement();
}
// 2. If ELSE then Skip until ENDIF
// ------------------------------------------------------------
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken)))
{
bool BackupDontExectuteIF = BasicIntrepeter.DontExectuteIF;
BasicIntrepeter.DontExectuteIF = true;
while (
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))) &&
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
{
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(IfToken))) BasicIntrepeter.ProcessNextStatement();
BasicIntrepeter.CodeParser.Next();
}
BasicIntrepeter.DontExectuteIF = BackupDontExectuteIF;
}
// 3. If ENDOFINPUT then throw error
// ------------------------------------------------------------
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
{
throw new MFBasic.Exceptions.BasicLanguageException(MFBasic.Exceptions.BasicLanguageException.MULTILINE_IF_WITHOUT_ENDIF);
}
// Skip EndIf Token
BasicIntrepeter.CodeParser.Next();
}
else
{
// 1. Skip Tokens until ENDIF or ELSE
// ------------------------------------------------------------
bool BackupDontExectuteIF = BasicIntrepeter.DontExectuteIF;
BasicIntrepeter.DontExectuteIF = true;
while (
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))) &
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken))) &
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
{
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(IfToken))) BasicIntrepeter.ProcessNextStatement();
BasicIntrepeter.CodeParser.Next();
}
BasicIntrepeter.DontExectuteIF = BackupDontExectuteIF;
// 2. If ENDOFINPUT then throw error
// ------------------------------------------------------------
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
{
throw new MFBasic.Exceptions.BasicLanguageException(MFBasic.Exceptions.BasicLanguageException.MULTILINE_IF_WITHOUT_ENDIF);
}
// 3. If ELSE then Execute until ENDIF
// ------------------------------------------------------------
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken)))
{
// Skip ELSE
BasicIntrepeter.CodeParser.Next();
while (
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))) &&
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
{
// If NewLine skip it.
// So we can be sure that all ENDIF tokens are catched!
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfLineToken)))
{
BasicIntrepeter.CodeParser.Next();
continue;
}
if (!BasicIntrepeter.DontExectuteIF) BasicIntrepeter.ProcessNextStatement();
}
}
// 4. If ENDOFINPUT then throw error
// ------------------------------------------------------------
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
{
throw new MFBasic.Exceptions.BasicLanguageException(MFBasic.Exceptions.BasicLanguageException.MULTILINE_IF_WITHOUT_ENDIF);
}
// 5. Skip ENDIF
// ------------------------------------------------------------
BasicIntrepeter.CodeParser.Expect(typeof(EndIfToken));
}
}
else
{
///////////////////////////////////////////////////////////////////
//
// SINGLE LINE IF
//
///////////////////////////////////////////////////////////////////
// If outcome is true
if (ComparisonResult >= 1)
{
// 1. Process statement
// ------------------------------------------------------------
if (!BasicIntrepeter.DontExectuteIF) BasicIntrepeter.ProcessNextStatement();
// 2. If ELSE Skip until NEWLINE/ENDOFINPUT
// ------------------------------------------------------------
while ((!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfLineToken))) &&
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
{
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(IfToken))) BasicIntrepeter.ProcessNextStatement();
BasicIntrepeter.CodeParser.Next();
}
// 3. If EndIfToken and Dont Execute is true go back one program position
if ((BasicIntrepeter.DontExectuteIF) && (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))))
BasicIntrepeter.CodeParser.ProgramPosition--;
}
else
{
// 1. Skip until ELSE/NEWLINE/ENDOFINPUT
// ------------------------------------------------------------
bool BackupDontExectuteIF = BasicIntrepeter.DontExectuteIF;
BasicIntrepeter.DontExectuteIF = true;
while ((!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfLineToken))) &&
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken))) &&
(!BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndOfInputToken)))
)
{
if (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(IfToken))) BasicIntrepeter.ProcessNextStatement();
BasicIntrepeter.CodeParser.Next();
}
BasicIntrepeter.DontExectuteIF = BackupDontExectuteIF;
// 2. If ELSE excecute statement
// ------------------------------------------------------------
if ((BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(ElseToken))))
{
// Skip Next
BasicIntrepeter.CodeParser.Next();
// Execute Statement
// Don't execute if searching for ELSE/ENDIF
if (!BasicIntrepeter.DontExectuteIF) BasicIntrepeter.ProcessNextStatement();
}
// 3. If EndIfToken and Dont Execute is true go back one program position
if ((BasicIntrepeter.DontExectuteIF) && (BasicIntrepeter.CodeParser.CurrentToken.GetType().Equals(typeof(EndIfToken))))
BasicIntrepeter.CodeParser.ProgramPosition--;
}
}
}
