Re: [Caml-list] Run time error on exception

[Malcolm Matalka <mmatalka@gmail.com>]

Lorenzo Pomili <lorenzo.pomili85@gmail.com> writes:

> Thanks for reply, one more question there is a way in OCaml, for know if
> function can produce side effects? I mean automatic way not read
> documentation or source code ^^"

Nope.  At least not without some third-party tooling, I'm not aware of
any.

>
> 2018-02-01 8:10 GMT+01:00 Malcolm Matalka <mmatalka@gmail.com>:
>
>> Exceptions basically mean "runtime error".  This is why some APIs use
>> the result type instead of exceptions.  So the API could be something
>> like:
>>
>> val int_of_string : string -> (int, err) result
>>
>> where err is some error type.
>>
>> I wrote a blog post about this years ago, the APIs in it might be out
>> dated but the general concept is probably still applies:
>>
>> http://functional-orbitz.blogspot.se/2013/01/experiences-using-resultt-vs-
>> exceptions.html
>>
>> Lorenzo Pomili <lorenzo.pomili85@gmail.com> writes:
>>
>> > Friend of mine, pointed out to me a case in Reason who cause no compile
>> > time error but run time error, I had reimplemented similar case in OCaml:
>> >
>> >
>> >
>> > exception Generic_exc;;
>> >
>> > let string_of_string s = string_of_int (int_of_string s)
>> >
>> > let foo = string_of_string "foo"
>> >
>> > let fun_exeption x =
>> >     match x with
>> >     0 -> 0
>> >     | _ -> raise Generic_exc
>> > ;;
>> >
>> > let bar = string_of_int (fun_exeption 5)
>> >
>> >
>> >
>> > both foo and bar don't fail at compile time fail at run time, me and my
>> > friend also try to reimplement similar case (the first one with string
>> and
>> > int) in Elm, and Elm compiler just say you have to manage exeption,
>> because
>> > function can actualy return exeption instead of int.
>> >
>> > There is a compile params or similar for check this kind of error? is a
>> > side effect of have a multi-paradigm? and if is it, how to manage it?
>> >
>> > I belive I can use OCaml in functional way without just making attention
>> to
>> > not use side effect but if use of function like int_of_string can make
>> run
>> > time error, I probably approac to OCaml in wrong way, and I wanna
>> > understand how to correct it.
>>
>>