/// <summary>
/// Visit a parse tree produced by <see cref="Z80AsmParser.literalExpr"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitLiteralExpr([NotNull] Z80AsmParser.LiteralExprContext context)
{
return(VisitChildren(context));
}
/// <summary>
/// Visit a parse tree produced by <see cref="Generated.Z80AsmParser.literalExpr"/>.
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public override object VisitLiteralExpr(Z80AsmParser.LiteralExprContext context)
{
if (IsInvalidContext(context))
{
return(null);
}
var token = context.NormalizeToken();
if (token == "$")
{
return(new CurrentAddressNode());
}
ushort value;
// --- Hexadecimal literals
if (token.StartsWith("#"))
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = ushort.Parse(token.Substring(1), NumberStyles.HexNumber);
}
else if (token.StartsWith("0X"))
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = ushort.Parse(token.Substring(2), NumberStyles.HexNumber);
}
else if (token.EndsWith("H", StringComparison.OrdinalIgnoreCase))
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = (ushort)int.Parse(token.Substring(0, token.Length - 1),
NumberStyles.HexNumber);
}
// --- Binary literals
else if (token.StartsWith("%"))
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = (ushort)Convert.ToInt32(token.Substring(1).Replace("_", ""), 2);
}
else if (token.StartsWith("0B"))
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = (ushort)Convert.ToInt32(token.Substring(2).Replace("_", ""), 2);
}
// --- Character literals
else if (token.StartsWith("\""))
{
var charExpr = context.GetText();
var bytes = Z80Assembler.SpectrumStringToBytes(charExpr.Substring(1, charExpr.Length - 2));
value = bytes.Count == 0 ? (ushort)0x00 : bytes[0];
}
// --- Decimal literals
else
{
_numbers.Add(new TextSpan(context.Start.StartIndex, context.Start.StopIndex + 1));
value = (ushort)int.Parse(context.NormalizeToken());
}
return(new LiteralNode
{
LiteralValue = value
});
}
/// <summary>
/// Exit a parse tree produced by <see cref="Z80AsmParser.literalExpr"/>.
/// <para>The default implementation does nothing.</para>
/// </summary>
/// <param name="context">The parse tree.</param>
public virtual void ExitLiteralExpr([NotNull] Z80AsmParser.LiteralExprContext context)
{
}
/// <summary>
/// Visit a parse tree produced by <see cref="Generated.Z80AsmParser.literalExpr"/>.
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public override object VisitLiteralExpr(Z80AsmParser.LiteralExprContext context)
{
var token = context.NormalizeToken();
if (context.CURADDR() != null || context.MULOP() != null || context.DOT() != null)
{
AddSemiVar(context);
return(new CurrentAddressNode());
}
if (context.CURCNT() != null)
{
AddSemiVar(context);
return(new CurrentLoopCounterNode());
}
// --- Check for Boolean values
if (context.BOOLLIT() != null)
{
AddNumber(context);
var boolValue = new ExpressionValue(context.BOOLLIT().GetText().ToLower().Contains("t"));
return(new LiteralNode(boolValue));
}
// --- Check for real values
if (context.REALNUM() != null)
{
AddNumber(context);
return(double.TryParse(context.REALNUM().GetText(), out var realValue)
? new LiteralNode(realValue)
: new LiteralNode(ExpressionValue.Error));
}
// --- Check for string values
if (context.STRING() != null)
{
AddString(context);
var stringValue = context.STRING().NormalizeString();
return(new LiteralNode(stringValue));
}
ushort value;
// --- Hexadecimal literals
if (token.StartsWith("#"))
{
AddNumber(context);
value = ushort.Parse(token.Substring(1), NumberStyles.HexNumber);
}
else if (token.StartsWith("0X"))
{
AddNumber(context);
value = ushort.Parse(token.Substring(2), NumberStyles.HexNumber);
}
else if (token.StartsWith("$"))
{
AddNumber(context);
value = ushort.Parse(token.Substring(1), NumberStyles.HexNumber);
}
else if (token.EndsWith("H", StringComparison.OrdinalIgnoreCase))
{
AddNumber(context);
value = (ushort)int.Parse(token.Substring(0, token.Length - 1),
NumberStyles.HexNumber);
}
// --- Binary literals
else if (token.StartsWith("%"))
{
AddNumber(context);
value = (ushort)Convert.ToInt32(token.Substring(1).Replace("_", ""), 2);
}
else if (token.StartsWith("0B"))
{
AddNumber(context);
value = (ushort)Convert.ToInt32(token.Substring(2).Replace("_", ""), 2);
}
else if (token.EndsWith("b") || token.EndsWith("B"))
{
AddNumber(context);
value = (ushort)Convert.ToInt32(token.Substring(0, token.Length - 1).Replace("_", ""), 2);
}
// --- Octal literals
else if (token.EndsWith("q") || token.EndsWith("Q") || token.EndsWith("o") || token.EndsWith("O"))
{
AddNumber(context);
value = (ushort)Convert.ToInt32(token.Substring(0, token.Length - 1), 8);
}
// --- Character literals
else if (token.StartsWith("\"") || token.StartsWith("'"))
{
AddString(context);
var charExpr = context.GetText();
var bytes = Z80Assembler.SpectrumStringToBytes(charExpr.Substring(1, charExpr.Length - 2));
value = bytes.Count == 0 ? (ushort)0x00 : bytes[0];
}
// --- Decimal literals
else
{
AddNumber(context);
value = (ushort)int.Parse(context.NormalizeToken());
}
return(new LiteralNode(value));
}
