OCaml dynamic function name

Question

I have a list of tags:

let tags = ["div", "h1", "p"]

Can I generate a module which contains functions with those tags as names?

/* don't mind the syntax, it's Facebook's Reason (new interface to ocaml) */

let module DOM = {
   let div props children => Js.Unsafe.fun_call
        (Js.Unsafe.get dom (Js.string "div")) [|Js.Unsafe.inject props, Js.Unsafe.inject children|];
    let h1 props children => Js.Unsafe.fun_call
        (Js.Unsafe.get dom (Js.string "h1")) [|Js.Unsafe.inject props, Js.Unsafe.inject children|];
let p props children => Js.Unsafe.fun_call
        (Js.Unsafe.get dom (Js.string "p")) [|Js.Unsafe.inject props, Js.Unsafe.inject children|];

}

The tag name should become a function in the module... Is this possible?

This is kind of tangent to the question, but are you aware of [tyxml](https://ocsigen.org/tyxml/manual/) (and the associated [js_of_ocaml interface](https://ocsigen.org/js_of_ocaml/2.7/api/Tyxml_js)) ? — Drup, Jun 12 '16 at 22:03
but, you can generate a map or a hashtable, that maps strings to functions. — ivg, Jun 15 '16 at 17:33
Beware, your tags list is a list with a single triple element! Use semicolon between list elements, with comma you get tuples. — Str., Jun 15 '16 at 20:31

camlspotter · Accepted Answer · 2016-06-13T03:05:42.800

Assuming what you want to do is to build a module with names from a string list while program execution,

Short answer: No, OCaml is a static typed language and you cannot build a new variable name while program execution.

Longer answer: you could use meta-programming: build a source code with names your want then compile it and dynamically link the compiled module. But this is not a regular way of using OCaml at all. In addition, looking at your environment, OCaml (or Reason) to output Js code, you likely need to have an OCaml (or Reason) compiler compiled to Js, which is hard and should be avoided.

Conclusion: No, you cannot.

I feared as much. Thanks for the answer! – Seneca Jun 13 '16 at 06:04 — Seneca, Jun 13 '16 at 06:04

OCaml dynamic function name

1 Answers1