public override SyntaxTreeNode Make(ObjectStream <MyToken> input, MyDiscardDelegate <MyToken> discarder)
{
Ensure(input, discarder);
// Ignora código descartável inicialmente
input.Discard(discarder);
if (input.EndOfStream())
{
return(null);
}
var initialPos = input.GetPosition();
var token = input.Next();
if (token == null || (CalcTwoNumbersTokenClass)token.Class != (CalcTwoNumbersTokenClass)GetTokenClass())
{
input.SetPosition(initialPos);
return(null);
}
if (string.IsNullOrEmpty((string)token.Content))
{
throw new SyntaxAnalysisException("Invalid content for NUMBER element");
}
uint number = 0;
if (!uint.TryParse((string)token.Content, out number))
{
throw new SyntaxAnalysisException("Invalid number value for NUMBER element");
}
return(new UIntegerTreeNode(number));
}
public override MyToken[] Eval(ObjectStream <Char> input, MyDiscardDelegate <char> discarder)
{
Ensure(input, discarder);
// Ignora código descartável inicialmente
input.Discard(discarder);
if (input.EndOfStream())
{
return(null);
}
var initialPos = input.GetPosition();
char character = input.Next();
if (character != _character)
{
input.SetPosition(initialPos);
return(null);
}
var token = new MyToken(
GetTokenClass(),
initialPos,
input.GetPosition(),
null
);
return(new MyToken[] { token });
}
public override SyntaxTreeNode Make(ObjectStream <MyToken> input, MyDiscardDelegate <MyToken> discarder)
{
Ensure(input, discarder);
// Ignora código descartável inicialmente
input.Discard(discarder);
if (input.EndOfStream())
{
return(null);
}
var initialPos = input.GetPosition();
// O primeiro token é só um marcador (etiqueta) pra indicar
// um elemento válido
var tag = input.Next();
if (tag == null || (CalcTwoNumbersTokenClass)tag.Class != (CalcTwoNumbersTokenClass)GetTokenClass())
{
input.SetPosition(initialPos);
return(null);
}
var numberLeftNode = ExpressionElements[0].Make(input, discarder);
var plusNode = ExpressionElements[1].Make(input, discarder);
var numberRightNode = ExpressionElements[2].Make(input, discarder);
if (numberLeftNode == null || plusNode == null || numberRightNode == null)
{
input.SetPosition(initialPos);
return(null);
}
var exprTreeNode = new SyntaxTreeNode();
plusNode.AddChildNode(numberLeftNode);
plusNode.AddChildNode(numberRightNode);
exprTreeNode.AddChildNode(plusNode);
return(exprTreeNode);
}
public override MyToken[] Eval(ObjectStream <Char> input, MyDiscardDelegate <char> discarder)
{
Ensure(input, discarder);
// Ignora código descartável inicialmente
input.Discard(discarder);
var initialPos = input.GetPosition();
var foundChars = new List <Char>();
while (!input.EndOfStream())
{
var pos = input.GetPosition();
char c = input.Next();
if (!_validChars.Contains(c))
{
input.SetPosition(pos);
break;
}
foundChars.Add(c);
}
if (!foundChars.Any())
{
input.SetPosition(initialPos);
return(null);
}
var token = new MyToken(
GetTokenClass(),
initialPos,
input.GetPosition(),
new string(foundChars.ToArray())
);
return(new MyToken[] { token });
}
public override SyntaxTreeNode Make(ObjectStream <MyToken> input, MyDiscardDelegate <MyToken> discarder)
{
Ensure(input, discarder);
// Ignora código descartável inicialmente
input.Discard(discarder);
if (input.EndOfStream())
{
return(null);
}
var initialPos = input.GetPosition();
var token = input.Next();
if (token == null || (CalcTwoNumbersTokenClass)token.Class != (CalcTwoNumbersTokenClass)GetTokenClass())
{
input.SetPosition(initialPos);
return(null);
}
return(new SumOperatorTreeNode());
}