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 void AfterGettingLastThereAreNoMoreIsSet()
{
Token firstToken = new MinusToken();
var tokens = new List <Token>()
{
firstToken
};
var walker = new TokensWalker(tokens);
walker.GetNext();
Assert.IsFalse(walker.ThereAreMoreTokens);
}
public void CanGetExisting()
{
Token firstToken = new MinusToken();
var tokens = new List <Token>()
{
firstToken
};
var walker = new TokensWalker(tokens);
Assert.IsTrue(walker.ThereAreMoreTokens);
var first = walker.GetNext();
Assert.AreEqual(firstToken, first);
}
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 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));
}