public static IType Unroll(IType type)
{
/*
(TApp TCRec (TAbs unique type3)) = type
return UnrollRecursiveType(type3, unique);
*/
if (type is TApp)
{
IType type1 = ((TApp)type).Function;
IType type2 = ((TApp)type).Argument;
if (type1 is TCRec)
{
if (type2 is TAbs)
{
Unique unique = ((TAbs)type2).Parameter;
IType type3 = ((TAbs)type2).Body;
return UnrollRecursiveType(type3, unique);
}
}
}
throw new ArgumentException(
string.Format(
"{0} is not a recursive type", type.Show()
)
);
}
private IType CheckFunctionTypeApp(
IType parameterType,
IType returnType,
IType argumentType
)
{
if (!argumentType.Equals(parameterType))
{
throw new ArgumentException(
string.Format(
"unexpected {0}, expected {1}",
argumentType.Show(),
parameterType.Show()
)
);
}
return returnType;
}
