Type Providers, Record / Union Types and Constant Type unsupported

When writing type providers you are required to define code that will run at run-time with a quotation. This in itself is not a problem, however if you try and pass a none native type to the quotation you will receive the following error,

Unsupported constant type: xxxx

There is a stack-overflow post here which has an example and a good explanation of the reasons why. A typical work around is to use each field from a record and pass it to a function call in the quotation as an array or as individual parameters. Either way this can end up being quite painful.

So how can we work around this. Well, what we need to do is build a new instance of the object we are trying to pass to the quotation within the quotation itself, and then use the variable that holds this new instance as the parameter…