* Re: [Caml-list] how to convert strings to Ocaml values at run-time?
2014-02-23 20:24 ` Matej Kosik
@ 2014-02-24 1:30 ` Francois Berenger
2014-02-24 5:05 ` Tianyi Cui
2014-02-24 13:48 ` Matthias Puech
2 siblings, 0 replies; 6+ messages in thread
From: Francois Berenger @ 2014-02-24 1:30 UTC (permalink / raw)
To: caml-list
On 02/24/2014 05:24 AM, Matej Kosik wrote:
> On 23/02/14 13:12, Tianyi Cui wrote:
>> If you know the type of this string in advance, you can do so with ocaml_plugin: https://github.com/janestreet/ocaml_plugin
>
> Hm, imagine that the expected type is:
>
> 'a * 'a -> bool
>
> Now, if user provides a string, say:
>
> "fun (a,b) -> a = b"
>
> how can I convert that string to Ocaml value of the above type (like how toplevel does it)?
>
> Is this something ocaml_plugin is able to do for me? I've failed to figure out the trick.
I think MLdonkey could do that, but I have no idea how it was doing it.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Caml-list] how to convert strings to Ocaml values at run-time?
2014-02-23 20:24 ` Matej Kosik
2014-02-24 1:30 ` Francois Berenger
@ 2014-02-24 5:05 ` Tianyi Cui
2014-02-24 13:48 ` Matthias Puech
2 siblings, 0 replies; 6+ messages in thread
From: Tianyi Cui @ 2014-02-24 5:05 UTC (permalink / raw)
To: Matej Kosik; +Cc: caml-list
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You can try to compile and run the hello_world example of ocaml_plugin:
https://github.com/janestreet/ocaml_plugin/blob/master/hello_world
It has a Plugin_intf module to specify the type of module expected from
loaded file. For you, it should probably be:
module type S = sig
val equal : ('a * 'a) -> bool
end
Then you can use Ocaml_compiler module to dynamically load modules with
this signature as demonstrated in run.ml
On Mon, Feb 24, 2014 at 4:24 AM, Matej Kosik <
5764c029b688c1c0d24a2e97cd764f@gmail.com> wrote:
> On 23/02/14 13:12, Tianyi Cui wrote:
> > If you know the type of this string in advance, you can do so with
> ocaml_plugin: https://github.com/janestreet/ocaml_plugin
>
> Hm, imagine that the expected type is:
>
> 'a * 'a -> bool
>
> Now, if user provides a string, say:
>
> "fun (a,b) -> a = b"
>
> how can I convert that string to Ocaml value of the above type (like how
> toplevel does it)?
>
> Is this something ocaml_plugin is able to do for me? I've failed to figure
> out the trick.
>
> --
> Caml-list mailing list. Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs
>
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Caml-list] how to convert strings to Ocaml values at run-time?
2014-02-23 20:24 ` Matej Kosik
2014-02-24 1:30 ` Francois Berenger
2014-02-24 5:05 ` Tianyi Cui
@ 2014-02-24 13:48 ` Matthias Puech
2 siblings, 0 replies; 6+ messages in thread
From: Matthias Puech @ 2014-02-24 13:48 UTC (permalink / raw)
To: caml-list
Hi,
I am not sure if I understand your question correctly, but I guess you
could:
- lex/parse the string to an untyped type of AST [term] as usual, and then
- have the type checking function take a [term] and produce an AST
annotated with types ['a typed_term]. This type could be either:
- a GADT, in which case you would need an evaluation function [eval
: type a. a typed_term -> a], by recursion on the typed term
- or, à la Finally Tagless [1], an abstract type declared in a
module together with values implementing the various primitives.
The thing to remember here I think is to "box" the type ['a] of the
expression parsed into a type annotation, i.e., ['a typed_term].
However, I fear it is going to be difficult to extend this approach to
polymorphism.
Hope it helps,
-m
[1]: http://okmij.org/ftp/tagless-final/#tagless-final
On 02/23/2014 09:24 PM, Matej Kosik wrote:
> On 23/02/14 13:12, Tianyi Cui wrote:
>> If you know the type of this string in advance, you can do so with ocaml_plugin: https://github.com/janestreet/ocaml_plugin
> Hm, imagine that the expected type is:
>
> 'a * 'a -> bool
>
> Now, if user provides a string, say:
>
> "fun (a,b) -> a = b"
>
> how can I convert that string to Ocaml value of the above type (like how toplevel does it)?
>
> Is this something ocaml_plugin is able to do for me? I've failed to figure out the trick.
>
^ permalink raw reply [flat|nested] 6+ messages in thread