Needed: utility to surface properties and methods of base type

[jackfoxy]

A useful utility would do one-time code generation creating source to populate all the methods and properties of the underlying type as well as functions from the type's module (if it exists), probably using reflection, for the dependent type. Does not have to be fancy. Does not have to be part of the runtime (although I can imagine it could be, at least to produce generated code as a string), and does not need to be part of the design time either. Of course custom coding may still be required in some cases.

This would make #1 less of an issue.

Example:

module rec RecursiveModule =
  module MyType =
    let createBaseTypeElement (config : ConfigType) (value : T1) =
        ...

    type MyTypeValidatorOrDiscriminator(config) = 
        inherit Pi<ConfigType, T1, BaseType>(config, createBaseTypeElement )

    // insert generated properties and functions here, operating on MyType.Value
    let BaseTypeMethod1 (x : MyType) = ...
    ...

  type MyType = DependentType<MyType.MyTypeValidatorOrDiscriminator, ConfigType, T1, BaseType>

[robkuz]

I am not sure what you try to do here.
can you give some usage examples?

[jackfoxy]

Take the example

module rec RecursiveModule =
    module NonEmptySet =
        let verifyNonEmptySet _ (value : Set<'T>) =
            if value.Count > 0 then
                Some value  
            else
                None

        type NonEmptySetValidator<'T when 'T : comparison>() = 
            inherit Pi<unit, Set<'T>, Set<'T> option>((), verifyNonEmptySet)
 
    type NonEmptySet<'T  when 'T : comparison> = SomeDependentType<NonEmptySet.NonEmptySetValidator<'T>, unit, Set<'T>, Set<'T>>   

In order to compute the union of NonEmptySets you would have to write

let xs =
    Set.union nonEmptySet1.Value nonEmptySet2.Value
    |> NonEmptySet.Create

It is possible to write a code generator that reflects all the public functions in the Microsoft.FSharp.Collections.Set module and generates code like

/// Computes the union of two NonEmptySets
let union (nonEmptySet1 : NonEmptySet) (nonEmptySet2 : NonEmptySet) =
    Set.union nonEmptySet1.Value nonEmptySet2.Value
    |> NonEmptySet.Create

After reviewing and placing the code in the module RecursiveModule.NonEmptySet you can use the following code:

let xs = NonEmptySet.union nonEmptySet1 nonEmptySet2

NonEmptySet is a good example of why this generated code is only a "template" and requires human review and intervention. For instance Set.difference can result in an empty Set.