I have a mostly successful monad implementation for COM interop.

COM requires that if you acquire an object reference then you have to eventually release it. My code was getting messy managing COM object references with try/finally. Now with a monad managing object references the code ends up being a lot cleaner. If references are not released properly, the host process (such as Excel) may keep running in the background.

I followed the F# 2.0 specification (and several blog posts) to come up with an implementation that is based on custom "result", "bind" and "catch" implementations and boilerplate code from the example given in the F# specification.

Please see: [link:gist.github.com]

I would like to be able to use for...yield with this monad implementation as in:

1

let! aList = com {for i in 1..n do yield! getData i}

I am stuck at this point. I don't know how to add Yield/YieldFrom implementations to make this happen.

The default implementation I have compiles but returns unit not a seq or list.