public IParseNode Parse(TokenWalker walker)
{
Debug.Assert(TermParser != null);
IParseNode result;
if (walker.NextIs <MinusToken>())
{
var lexem = walker.Pop();
result = new UnaryMinusOperator(TermParser.Parse(walker), lexem.Position);
}
else
{
result = TermParser.Parse(walker);
}
while (walker.NextIsLineOperator())
{
var lexem = walker.Pop();
result = lexem.Token switch
{
MinusToken _ => new MinusOperator(result, TermParser.Parse(walker), lexem.Position),
PlusToken _ => new PlusOperator(result, TermParser.Parse(walker), lexem.Position),
_ => result
};
}
return(result);
}
}
public IEnumerable <BrainfuckToken> Parse(TextReader streamReader)
{
var ret = new List <BrainfuckToken>();
var leftBracketStack = new Stack <LeftBracketToken>();
BrainfuckToken prev = null;
var index = -1;
while (0 <= streamReader.Peek())
{
++index;
var c = (char)streamReader.Read();
BrainfuckToken current = null;
switch (c)
{
case '>':
current = new RightShiftToken();
break;
case '<':
current = new LeftShiftToken();
break;
case '+':
current = new PlusToken();
break;
case '-':
current = new MinusToken();
break;
case '.':
current = new DotToken();
break;
case ',':
current = new SemicolonToken();
break;
case '[':
{
var leftBracket = new LeftBracketToken();
leftBracketStack.Push(leftBracket);
current = leftBracket;
}
break;
case ']':
{
if (leftBracketStack.Count == 0)
{
throw new InvalidOperationException();
}
var leftBracket = leftBracketStack.Pop();
var rightBracket = new RightBracketToken();
leftBracket.RightBracketToken = rightBracket;
rightBracket.LeftBracketToken = leftBracket;
current = rightBracket;
}
break;
}
if (current == null)
{
continue;
}
current.Index = index;
prev?.SetNextIndexToken(current);
prev = current;
ret.Add(current);
}
if (leftBracketStack.Count != 0)
{
throw new InvalidOperationException();
}
return(ret);
}
public Token GetToken()
{
State = LexicAnalyserState.Initial;
Value = HasNext ? Character.ToString() : "";
Token token = null;
while (HasNext && token == null)
{
switch (State)
{
case LexicAnalyserState.Initial:
HandleInitial();
break;
case LexicAnalyserState.NonTerminal:
token = new NonTerminalToken(Value);
CurrentIndex++;
break;
case LexicAnalyserState.Space:
token = new SpaceToken();
CurrentIndex++;
break;
case LexicAnalyserState.Terminal:
token = new TerminalToken(Value);
CurrentIndex++;
break;
case LexicAnalyserState.Empty:
token = new EmptyToken();
CurrentIndex++;
break;
case LexicAnalyserState.NewLine:
token = new NewLineToken(Value);
CurrentIndex++;
break;
case LexicAnalyserState.Identifier:
token = new IdentifierToken(Value);
CurrentIndex++;
break;
case LexicAnalyserState.Number:
token = new NumberToken(Value);
CurrentIndex++;
break;
case LexicAnalyserState.Var:
token = new VarToken();
CurrentIndex++;
break;
case LexicAnalyserState.Write:
token = new WriteToken();
CurrentIndex++;
break;
case LexicAnalyserState.Read:
token = new ReadToken();
CurrentIndex++;
break;
case LexicAnalyserState.If:
token = new IfToken();
CurrentIndex++;
break;
case LexicAnalyserState.End:
token = new EndToken();
CurrentIndex++;
break;
case LexicAnalyserState.Then:
token = new ThenToken();
CurrentIndex++;
break;
case LexicAnalyserState.Begin:
token = new BeginToken();
CurrentIndex++;
break;
case LexicAnalyserState.While:
token = new WhileToken();
CurrentIndex++;
break;
case LexicAnalyserState.Do:
token = new DoToken();
CurrentIndex++;
break;
case LexicAnalyserState.SemiColon:
token = new SemiColonToken();
CurrentIndex++;
break;
case LexicAnalyserState.OpenParentheses:
token = new OpenParenthesesToken();
CurrentIndex++;
break;
case LexicAnalyserState.CloseParentheses:
token = new CloseParenthesesToken();
CurrentIndex++;
break;
case LexicAnalyserState.Plus:
token = new PlusToken();
CurrentIndex++;
break;
case LexicAnalyserState.Sub:
token = new SubToken();
CurrentIndex++;
break;
case LexicAnalyserState.Great:
token = new GreatToken();
CurrentIndex++;
break;
case LexicAnalyserState.Less:
token = new LessToken();
CurrentIndex++;
break;
case LexicAnalyserState.Equal:
token = new EqualToken();
CurrentIndex++;
break;
case LexicAnalyserState.Repeat:
token = new RepeatToken();
CurrentIndex++;
break;
case LexicAnalyserState.Until:
token = new UntilToken();
CurrentIndex++;
break;
case LexicAnalyserState.Attribution:
token = new AttributionToken();
CurrentIndex++;
break;
case LexicAnalyserState.NotEqual:
token = new NotEqualToken();
CurrentIndex++;
break;
case LexicAnalyserState.GreatOrEqual:
token = new GreatOrEqualToken();
CurrentIndex++;
break;
case LexicAnalyserState.LessOrEqual:
token = new LessOrEqualToken();
CurrentIndex++;
break;
default:
throw new ArgumentOutOfRangeException();
}
}
return(token);
}
public BrainfuckTokenSequence Parse(TextReader streamReader, BrainfuckMemoryTape memoryTape = null)
{
memoryTape = memoryTape ?? new BrainfuckMemoryTape();
var leftBracketStack = new Stack <LeftBracketToken>();
BrainfuckToken first = null;
BrainfuckToken prev = null;
var index = -1;
while (0 <= streamReader.Peek())
{
++index;
var c = (char)streamReader.Read();
BrainfuckToken current = null;
switch (c)
{
case '>':
current = new RightShiftToken();
break;
case '<':
current = new LeftShiftToken();
break;
case '+':
current = new PlusToken();
break;
case '-':
current = new MinusToken();
break;
case '.':
current = new DotToken();
break;
case ',':
current = new SemicolonToken();
break;
case '[':
{
var leftBracket = new LeftBracketToken();
leftBracketStack.Push(leftBracket);
current = leftBracket;
}
break;
case ']':
{
if (leftBracketStack.Count == 0)
{
throw new InvalidOperationException();
}
var leftBracket = leftBracketStack.Pop();
var rightBracket = new RightBracketToken();
leftBracket.RightBracketToken = rightBracket;
rightBracket.LeftBracketToken = leftBracket;
current = rightBracket;
}
break;
default:
break;
}
if (current == null)
{
continue;
}
current.MemoryTape = memoryTape;
current.Index = index;
if (prev != null && prev.Next == null)
{
prev.SetNextIndexToken(current);
}
prev = current;
if (first != null)
{
continue;
}
first = current;
}
if (leftBracketStack.Count != 0)
{
throw new InvalidOperationException();
}
return(new BrainfuckTokenSequence(first));
}
