/// <summary>
/// block2 = block3, { sign3, block3 } ;
/// </summary>
/// <returns></returns>
public SyntaxTreeNode ParseBlock2()
{
// ? [ "-" | "!" ]
Lexem invertLexem = null;
if(PeekLexem(LexemType.Subtract, LexemType.Not))
{
invertLexem = GetLexem();
SkipLexem();
}
// block3
var node = ParseBlock3();
if(invertLexem != null)
{
if (invertLexem.Type == LexemType.Subtract)
node = new OperatorInvertNode(node);
else
node = new OperatorNegateNode(node);
node.Lexem = invertLexem;
}
// { sign3, block3 }
while (PeekLexem(LexemTypeGroup.Sign3))
{
var lexem = GetLexem(0, true);
if (lexem.Type == LexemType.NewLine) return node;
SkipLexem();
BinaryOperatorNode newNode;
switch (lexem.Type)
{
case LexemType.Add: newNode = new OperatorAddNode(); break;
case LexemType.Subtract: newNode = new OperatorSubtractNode(); break;
default: throw new NotImplementedException();
}
// block3
newNode.Left = node;
newNode.Right = ParseBlock3();
newNode.Lexem = lexem;
node = newNode;
}
return node;
}
/// <summary>
/// array_expr = [ "-" ], ( literal | identifier | "(" expr ")" ) ;
/// </summary>
/// <returns></returns>
public SyntaxTreeNode ParseArrayExpr()
{
SyntaxTreeNode node = null;
// ? "-"
var invert = false;
if (PeekLexem(LexemType.Subtract))
{
invert = true;
SkipLexem();
}
if (PeekLexem(LexemTypeGroup.Literal))
node = ParseLiteral();
else if (PeekLexem(LexemType.Identifier))
{
var lexem = GetLexem();
var idNode = new IdentifierGetNode(lexem.Data);
if (lexem.Data[0] == '@')
{
idNode.Name = idNode.Name.Substring(1, idNode.Name.Length - 1);
idNode.AtmarkPrefix = true;
}
node = idNode;
node.Lexem = lexem;
SkipLexem();
}
else if (PeekLexem(LexemType.ParenOpen))
{
// "("
SkipLexem();
node = ParseExpr();
// ")"
if (!PeekLexem(LexemType.ParenClose)) Error(Resources.errParenExpected);
SkipLexem(true);
}
else
Error(Resources.errArrayExpressionParensExpected);
// invert if needed
if (invert)
node = new OperatorInvertNode(node);
return node;
}
