F# Quotations - traversing into function calls represented by a Value -

i've spent few hours trying grips f# quotations, i've come across bit of road block. requirement take simple functions (just integers,+,-,/,*) out of discriminated union type , generate expression tree used generate c code. know possible using quotations 'direct' functions.

my problem expression tree seems terminate "value", , can't figure out how traverse value.

my questions whether possible in situation? or there other approaches worth considering.

type functype =  | of (int -> int -> int) | b | c  [<reflecteddefinition>] let add x y = x + y   let myfunc1 = (fun x y -> x + y ) let myfunc2 = add   let thefunc expr =      match expr     | a(x) ->         <@ x @>     | _ ->         failwith "fail"  printfn "%a" (thefunc myfunc1) // prints "value (<fun:myfunc1@14>)" printfn "%a" (thefunc myfunc2) // prints "value (<fun:myfunc2@15>)" printfn "%a" <@ fun x y -> x + y @> // generates usable expression tree 

quotations represent f# code quoted syntactically. means if write <@ x @>, quotation contain value case specifying quoted has specified value. (variables automatically replaced values if variable defined outside of quotation).

you can quotation of code explicitly quoted using <@ .. @> or of function marked reflecteddefinition , referred name in quotation (e.g. <@ add @> not example let f = add in <@ f @>).

to able snippet suggests, you'll need store quotations in functype (so lambda function write quoted , can body). like:

type functype =    | of expr<int -> int -> int>   | b | c  [<reflecteddefinition>] let add x y = x + y  let myfunc1 = <@ fun x y -> x + y @> let myfunc2 = <@ add @>  let thefunc expr =      match expr     | a(x) -> x     | _ -> failwith "fail" 

this should work functions marked reflecteddefinition too. extract body of function need add (you'll need substitute arguments of function parameters, should give idea):

match expr | lambdas(_, body) ->      match body      | call(_, mi, _) when expr.trygetreflecteddefinition(mi) <> none ->       let func = expr.trygetreflecteddefinition(mi)       match func        | some(lambdas(_, body)) ->           // 'body' quotation of body       | _ -> failwith "not supported function"     | _ -> failwith "not supported function" | _ -> failwith "not supported expression"