Have you looked at tools such as Delphi, Lazarus etc and the approach used to build GUI components which can be added at build time or at runtime?

If you are interested in talking about this, do let me know.

> We are also actively working on a visual editor that lets users drag and drop widgets. Such capabilities are difficult or impossible to achieve with imperative APIs

I don't think you have ever used an imperative API, have you?

I used VB, then Delphi, then C++ builder and now use Lazarus, and there's no declarative equivalent that is easier or faster than those.

In the examples you mentioned, the UI is typically described in XML or form files (.dfm), which is essentially a declarative approach, and clearly not described in imperative code. Although they may not be intended to be edited by hand, the underlying representation is still declarative in nature.

Agreed, but they were easily achieved with imperative APIs.

This is the statement I was contending:

> We are also actively working on a visual editor that lets users drag and drop widgets. Such capabilities are difficult or impossible to achieve with imperative APIs

Maybe I should have said "there's no declarative-only equivalents that's easier or faster".

As someone else pointed out elsethread, declarative is a subset of imperative, so it's easy to produce an imperative API that consumes machine-generated declarations, but not so easy to use a declarative-only framework to reproduce the ease and speed of Delphi, Lazarus, etc.