internal static ConversionSymbol ResolveDynamicConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (expr.Datatype.NativeType == NativeType.Object)
{
var inner = Conversion(expr, Compilation.Get(NativeType.Usual), options);
var outer = Conversion(TypeConversion.Bound(expr, Compilation.Get(NativeType.Usual), inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
return(null);
}
internal static ConversionSymbol ResolveUsualConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (expr.Datatype.NativeType == NativeType.Usual)
{
if (type.NativeType == NativeType.Object)
{
if (options.HasFlag(BindOptions.BoxUsual))
{
return(ConversionSymbol.Create(ConversionKind.Boxing));
}
else
{
MethodSymbol converter = null;
ResolveConversionMethod(expr, type, Compilation.Get(NativeType.Usual).Lookup(XSharpFunctionNames.ToObject), ref converter, options);
if (converter != null)
{
return(ConversionSymbol.Create(ConversionKind.ImplicitUserDefined, converter));
}
}
}
else
{
MethodSymbol converter = null;
ResolveConversionMethod(expr, Compilation.Get(NativeType.Object), Compilation.Get(NativeType.Usual).Lookup(XSharpFunctionNames.ToObject), ref converter, options);
if (converter != null)
{
var inner = ConversionSymbol.Create(ConversionKind.ImplicitUserDefined, converter);
var outer = type.IsReferenceType ? ConversionSymbol.Create(ConversionKind.ExplicitReference)
: type.IsValueType ? ConversionSymbol.Create(ConversionKind.Unboxing)
: ConversionSymbol.Create(ConversionKind.NoConversion);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
}
}
else if (type.NativeType == NativeType.Usual && expr.Datatype.IsReferenceType)
{
var inner = Conversion(expr, Compilation.Get(NativeType.Object), options | BindOptions.Explicit);
if (inner.Exists)
{
var outer = Conversion(TypeConversion.Bound(expr, Compilation.Get(NativeType.Object), inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
}
return(null);
}
internal static ConversionSymbol ResolveByRefConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (type.IsByRef && TypesMatch(expr.Datatype, type.ElementType))
{
return(ConversionSymbol.CreateByRef());
}
else
{
var inner = ConversionSymbol.Create(ConversionKind.Deref);
var outer = Conversion(TypeConversion.Bound(expr, expr.Datatype.ElementType, inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
return(null);
}
internal static void Convert(ref Expr e, TypeSymbol type, ConversionSymbol conv)
{
switch (conv.Kind)
{
case ConversionKind.Identity:
break;
case ConversionKind.ConstantReduction:
e = LiteralExpr.Bound(((ConversionSymbolToConstant)conv).Constant);
break;
case ConversionKind.NoConversion:
throw ConversionError(e, type);
case ConversionKind.NoImplicitConversion:
throw ImplicitConversionError(e, type);
default:
e = TypeConversion.Bound(e, type, conv);
break;
}
}
internal static ConversionSymbol ResolveEnumConversion(Expr expr, TypeSymbol type, BindOptions options)
{
if (expr.Datatype.IsEnum)
{
if (TypesMatch(expr.Datatype.EnumUnderlyingType, type))
{
return(ConversionSymbol.Create(ConversionKind.ImplicitEnumeration));
}
else
{
var inner = ConversionSymbol.Create(ConversionKind.ImplicitEnumeration);
var outer = Conversion(TypeConversion.Bound(expr, expr.Datatype.EnumUnderlyingType, inner), type, options);
if (outer.Exists)
{
return(ConversionSymbol.Create(outer, inner));
}
}
}
if (type.IsEnum && options.HasFlag(BindOptions.Explicit))
{
if (TypesMatch(type.EnumUnderlyingType, expr.Datatype))
{
return(ConversionSymbol.Create(ConversionKind.ExplicitEnumeration));
}
else
{
var inner = Conversion(expr, type.EnumUnderlyingType, options);
if (inner.Exists)
{
var outer = ConversionSymbol.Create(ConversionKind.ExplicitEnumeration);
return(ConversionSymbol.Create(outer, inner));
}
}
}
return(null);
}