/// <summary>
/// Visit a parse tree produced by <see cref="Generated.Z80AsmParser.operand"/>.
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public override object VisitOperand(Z80AsmParser.OperandContext context)
{
if (IsInvalidContext(context))
{
return(null);
}
// --- The context has exactly one child
var child = context.GetChild(0);
var op = new Operand();
if (child is Z80AsmParser.Reg8Context)
{
op.Type = OperandType.Reg8;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.Reg8IdxContext)
{
op.Type = OperandType.Reg8Idx;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.Reg8SpecContext)
{
op.Type = OperandType.Reg8Spec;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.Reg16Context)
{
op.Type = OperandType.Reg16;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.Reg16IdxContext)
{
op.Type = OperandType.Reg16Idx;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.Reg16SpecContext)
{
op.Type = OperandType.Reg16Spec;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.MemIndirectContext)
{
var expContext = child.GetChild(1) as Z80AsmParser.ExprContext;
op.Type = OperandType.MemIndirect;
op.Expression = (ExpressionNode)VisitExpr(expContext);
}
else if (child is Z80AsmParser.RegIndirectContext)
{
op.Type = OperandType.RegIndirect;
op.Register = child.GetText().NormalizeToken();
}
else if (child is Z80AsmParser.CPortContext)
{
op.Type = OperandType.CPort;
}
else if (child is Z80AsmParser.IndexedAddrContext)
{
op.Type = OperandType.IndexedAddress;
var indexedAddrContext = child as Z80AsmParser.IndexedAddrContext;
if (indexedAddrContext.ChildCount > 3)
{
op.Expression = indexedAddrContext.GetChild(3) is Z80AsmParser.LiteralExprContext
? (ExpressionNode)VisitLiteralExpr(
indexedAddrContext.GetChild(3) as Z80AsmParser.LiteralExprContext)
: indexedAddrContext.GetChild(3).NormalizeToken() == "["
? (ExpressionNode)VisitExpr(indexedAddrContext.GetChild(4) as Z80AsmParser.ExprContext)
: (ExpressionNode)VisitSymbolExpr(
indexedAddrContext.GetChild(3) as Z80AsmParser.SymbolExprContext);
}
op.Register = indexedAddrContext.GetChild(1).NormalizeToken();
op.Sign = indexedAddrContext.ChildCount > 3
? indexedAddrContext.GetChild(2).NormalizeToken()
: null;
}
else if (child is Z80AsmParser.ExprContext)
{
op.Type = OperandType.Expr;
op.Expression = (ExpressionNode)VisitExpr(child as Z80AsmParser.ExprContext);
}
return(op);
}
