Question

What’s the status of the Run() method in a computation method? I’ve seen it in several examples (here, here, here), and I’ve seen in it F#’s compiler source, yet it’s not in the spec or the MSDN documentation. I filed an issue in MS Connect about this and it was closed as “by design” without further explanations.

So is it deprecated/undocumented/unsupported? Should I avoid it?

UPDATE: MS Connect issue status was promptly changed and the MSDN page updated to include Run()

Answer 1

6.3.10 Computation Expressions

More specifically, computation
expressions are of the form
builder-expr { cexpr } where cexpr is,
syntactically, the grammar of
expressions with the additional
constructs defined in comp-expr.
Computation expressions are used for
sequences and other non-standard
interpretations of the F# expression
syntax. The expression builder-expr {
cexpr } translates to

let b = builder-expr in b.Run (b.Delay(fun () -> {| cexpr |}C)) 

for a fresh variable b. If no method Run exists on the inferred type of b when this
expression is checked, then that call is omitted. Likewise, if no method Delay exists on > the type of b when this expression is checked, then that call is omitted