private void Step2()
{
#if DEBUG
if( this.action.Type != ParserTable.ActionType.Step )
throw new InternalParserException(string.Format(
"Internal state is {0}, but ActionType.Reduction expected.",
this.action.Type));
if( this.phase != ParsingPhase.Step1 )
throw new InternalParserException(string.Format(
"Internal phase is {0}, but ParsingPhase.Step1 expected.",
this.phase));
#endif
this.phase = ParsingPhase.Step2;
this.stack.Push(this.action.Argument, this.CurrentInputSymbol);
if( !this.input.MoveNext() )
throw new UnexpectedEndOfSourceException();
}
private void Reduction3()
{
#if DEBUG
if( this.action.Type != ParserTable.ActionType.Reduction )
throw new InternalParserException(string.Format(
"Internal state is {0}, but ActionType.Reduction expected.",
this.action.Type));
if( this.phase != ParsingPhase.Reduction2 )
throw new InternalParserException(string.Format(
"Internal phase is {0}, but ParsingPhase.Reduction2 expected.",
this.phase));
#endif
this.phase = ParsingPhase.Reduction3;
this.stack.Push(this.goto_state, this.reduction_rule.LeftHandSide);
this.reduction_rule = null;
}
private void Step1()
{
#if DEBUG
if( this.action.Type != ParserTable.ActionType.Step )
throw new InternalParserException(string.Format(
"Internal state is {0}, but ActionType.Step expected.",
this.action.Type));
#endif
this.phase = ParsingPhase.Step1;
}
/// <summary>
/// Default constructor.
/// </summary>
public Parser()
{
this.stack = new ParserStack();
this.phase = ParsingPhase.NotParsing;
}
private void Reduction2()
{
#if DEBUG
if( this.action.Type != ParserTable.ActionType.Reduction )
throw new InternalParserException(string.Format(
"Internal state is {0}, but ActionType.Reduction expected.",
this.action.Type));
if( this.phase != ParsingPhase.Reduction1 )
throw new InternalParserException(string.Format(
"Internal phase is {0}, but ParsingPhase.Reduction1 expected.",
this.phase));
#endif
this.phase = ParsingPhase.Reduction2;
for( int i = 0; i < this.reduction_rule.RightHandSide.Count; ++i )
this.stack.Pop();
this.goto_state = this.table.GetGoto(this.CurrentState, this.grammar.IndexOf(this.reduction_rule.LeftHandSide));
if( this.goto_state == -1 )
this.phase = ParsingPhase.Error;
}
private void Reduction1()
{
#if DEBUG
if( this.action.Type != ParserTable.ActionType.Reduction )
throw new InternalParserException(string.Format(
"Internal state is {0}, but ActionType.Reduction expected.",
this.action.Type));
#endif
this.phase = ParsingPhase.Reduction1;
this.reduction_rule = this.grammar.Rules[this.action.Argument];
}
private void BeginNewPhase()
{
this.action = this.table.GetAction(this.CurrentState, this.grammar.IndexOf(this.CurrentInputSymbol));
switch( this.action.Type )
{
case ParserTable.ActionType.Accept:
this.phase = ParsingPhase.Accept;
break;
case ParserTable.ActionType.Error:
this.phase = ParsingPhase.Error;
break;
case ParserTable.ActionType.Reduction:
this.Reduction1();
break;
case ParserTable.ActionType.Step:
this.Step1();
break;
default:
throw new NotSupportedException(string.Format("ActionType '{0}' not supported.", this.action.Type.ToString()));
}
this.step_count += 1;
}
/// <summary>
/// Stops the ongoing parsing. If it was not parsing, it will have no effect.
/// </summary>
public void Stop()
{
if( !this.IsParsing )
return;
this.phase = ParsingPhase.NotParsing;
this.input = null;
this.OnPhaseChanged();
}
