Working with DSLs and Computation Expressions in F#

f you develop UI applications in F#, you probably miss the familiar Visual Studio form editor that comes with C# or VB. This is due to a simple reason: there are no partial classes in F#. This is precisely what the code generator behind the scenes would need to synthesize code for your design forms. While the F# team is working hard to find the best approach to support partial classes and bring the Visual Studio integration up to par with that of mainstream front-ends, there are a number of things you can do to bypass this soon-to-disappear annoyance.

For one, you can set up a multi-project solution and implement the UI as a C# or VB UI project, and code the rest of the application logic in F#. This works so well that it is hard to argue that you could do better unless you had in turn the ability to design the UI with F# code behind. But after you start making incremental changes to your UI project, various small issues start to crop up. One such issue is the accessibility of certain UI elements that you need for wiring event handlers; these need to be manually made public in your UI library project.