Implicit way to 'RequireQualifiedAccess' for all defined DUs

I propose we make it possible to implicitly require qualified access for all DUs declared in a project.

The existing way of approaching this problem in F# is to add an attribute ([<RequireQualifiedAccess>]) to every DU.

Often a lot if not all DUs are annotated with the [<RequireQualifiedAccess>] attribute. This adds a lot of noise that would not be required with this proposal.

(Example of how distracting RequireQualifiedAccess everywhere is)

[<RequireQualifiedAccess>]
type InstructionStepFormError =
    | TitleIsRequired
    | ShortDescriptionIsRequired
    | LongDescriptionIsRequired

[<RequireQualifiedAccess>]
type InstructionDocumentFormError =
    | Steps of Map<Guid, InstructionStepFormError list>
    | AtLeastOneStepRequired

[<RequireQualifiedAccess>]
type InstructionMetaFormError =
    | AtLeastOneOwner
    | AtLeastOneEquipment
    | TitleIsRequired
    | TitleAlreadyExists

[<RequireQualifiedAccess>]
type CreateInstructionFormError =
    | Meta of InstructionMetaFormError list
    | Document of InstructionDocumentFormError list

This could be enabled in the Project file.

It would also require an escape hatch for when qualified access should not be required. I would propose to change the RequireQualifiedAccessAttribute so it has 2 constructors.

• [<RequireQualifiedAccess>] -> same as [<RequireQualifiedAccess true>]

• [<RequireQualifiedAccess true>]

• [<RequireQualifiedAccess false>]

Pros and Cons

The advantages of making this adjustment to F# are ...

• removes noise
• allows developers/teams to choose their defaults

The disadvantages of making this adjustment to F# are ...

• code is not valid on its own, context is needed to know if qualified access is required.
• makes things more complicated

Extra information

Estimated cost (XS, S, M, L, XL, XXL): ?

Related suggestions: (put links to related suggestions here)

Affidavit (please submit!)

Please tick this by placing a cross in the box:

• This is not a question (e.g. like one you might ask on stackoverflow) and I have searched stackoverflow for discussions of this issue
• I have searched both open and closed suggestions on this site and believe this is not a duplicate
• This is not something which has obviously "already been decided" in previous versions of F#. If you're questioning a fundamental design decision that has obviously already been taken (e.g. "Make F# untyped") then please don't submit it.

Please tick all that apply:

• This is not a breaking change to the F# language design
• I or my company would be willing to help implement and/or test this (If provided with guidance and a lot of time)

For Readers

If you would like to see this issue implemented, please click the 👍 emoji on this issue. These counts are used to generally order the suggestions by engagement.

Start with the proposal and its 16-comment discussion, then review how the project file and RequireQualifiedAccessAttribute are currently defined. The work is done only when the language-design questions are resolved and the chosen project-wide behavior and opt-out mechanism are specified well enough for implementation and tests.