static IMethod ImplementIntoCaseConversion(this VirtualType type, IType valueType, IMethod caseCtor, bool isImplicit = true)
{
Debug.Assert(valueType == caseCtor.Parameters.Single().Type);
Debug.Assert(valueType.Kind != TypeKind.Interface); // can't have conversion from interface
Debug.Assert(valueType != type); // can't have conversion from itself
var caseFactory = new VirtualMethod(type, Accessibility.Public,
isImplicit ? "op_Implicit" : "op_Explicit",
new[] { new VirtualParameter(valueType, "item") },
returnType: type,
isStatic: true
);
caseFactory.BodyFactory = () => {
var @this = new IL.ILVariable(IL.VariableKind.Parameter, valueType, 0);
IL.ILInstruction body = new IL.NewObj(caseCtor)
{
Arguments = { new IL.LdLoc(@this) }
};
if (valueType.IsReferenceType == true)
{
// pass nulls
body = new IL.IfInstruction(
new IL.Comp(IL.ComparisonKind.Inequality, Sign.None, new IL.LdLoc(@this), new IL.LdNull()),
body,
new IL.LdNull()
);
}
return(EmitExtensions.CreateExpressionFunction(caseFactory, body));
};
type.Methods.Add(caseFactory);
return(caseFactory);
}
public static IMethod ImplementForwardingCaseFactory(this VirtualType type, string caseName, IMethod caseCtor, IMethod valueTypeCtor)
{
var valueType = caseCtor.Parameters.Single().Type;
Debug.Assert(valueType == valueTypeCtor.DeclaringType);
var caseFactory = new VirtualMethod(type, Accessibility.Public,
E.SymbolNamer.NameMethod(type, caseName, 0, valueTypeCtor.Parameters, isOverride: false),
valueTypeCtor.Parameters,
returnType: type,
isStatic: true,
doccomment: (valueTypeCtor as IWithDoccomment)?.Doccomment
);
caseFactory.BodyFactory = () => {
var call = new IL.NewObj(valueTypeCtor);
call.Arguments.AddRange(valueTypeCtor.Parameters.Select((p, i) => new IL.LdLoc(new IL.ILVariable(IL.VariableKind.Parameter, p.Type, i))));
return(EmitExtensions.CreateExpressionFunction(caseFactory,
new IL.NewObj(caseCtor)
{
Arguments = { call }
}
));
};
type.Methods.Add(caseFactory);
return(caseFactory);
}
public static IMethod ImplementBasicCaseFactory(this VirtualType type, string caseName, IMethod caseCtor)
{
var valueType = caseCtor.Parameters.Single().Type;
var doccomment = (valueType.GetDefinition() as IWithDoccomment)?.Doccomment;
var caseFactory = new VirtualMethod(type, Accessibility.Public,
E.SymbolNamer.NameMethod(type, caseName, 0, new [] { valueType }, isOverride: false),
new[] { new VirtualParameter(valueType, "item") },
returnType: type,
isStatic: true,
doccomment: doccomment
);
caseFactory.BodyFactory = () =>
EmitExtensions.CreateExpressionFunction(caseFactory,
new IL.NewObj(caseCtor)
{
Arguments = { new IL.LdLoc(new IL.ILVariable(IL.VariableKind.Parameter, valueType, 0)) }
}
);
type.Methods.Add(caseFactory);
return(caseFactory);
}
