[Caml-list] How to explain static typing to other people?

[Caml-list] How to explain static typing to other people?

[oliver]

Hello,

did you ever get the response, that one could use Java,
when you talked about the static typing advantages of
languages like OCaml or Haskell?

I often heard that and after trying to explain the differences
for a while, I  started to stop the discussion, because the other person
will not understand it. (Maybe it needs to be tried in the real world
to see the differences... discussing about it alone can't work, I guess.)

Here is a talk, that I enjoy(ed) viewing, because it's clearly
showing the advantages of static typing and IMHO this
guy has a lot of humor, making the talk fun to view:

  [ny-haskell] A Pragmatic Case for Static Typing with Brian Hurt
    http://vimeo.com/72870631


Ciao,
   Oliver

Re: [Caml-list] How to explain static typing to other people?

[Francois Berenger]

On 8/28/13 8:45 PM, oliver wrote:
> Hello,
>
> did you ever get the response, that one could use Java,
> when you talked about the static typing advantages of
> languages like OCaml or Haskell?

One advantage is that the OCaml (and Haskell) compilers automatically 
infer the correct type.

In Java, you must always manually input the type, as far as I remember.

> I often heard that and after trying to explain the differences
> for a while, I  started to stop the discussion, because the other person
> will not understand it. (Maybe it needs to be tried in the real world
> to see the differences... discussing about it alone can't work, I guess.)
>
> Here is a talk, that I enjoy(ed) viewing, because it's clearly
> showing the advantages of static typing and IMHO this
> guy has a lot of humor, making the talk fun to view:
>
>    [ny-haskell] A Pragmatic Case for Static Typing with Brian Hurt
>      http://vimeo.com/72870631
>
>
> Ciao,
>     Oliver
>

Re: [Caml-list] How to explain static typing to other people?

[Raoul Duke]

> One advantage is that the OCaml (and Haskell) compilers automatically infer
> the correct type.
>
> In Java, you must always manually input the type, as far as I remember.


i was under the impression, based on personal experience as well as
hear-say, that anybody /really/ using haskell or ocaml or some such
would actually be manually entering type signatures all the time,
because they do not want to later have some incomprehensible error
that does not point to a root cause.

Re: [Caml-list] How to explain static typing to other people?

[oliver]

On Wed, Aug 28, 2013 at 12:25:31PM -0700, Raoul Duke wrote:
> > One advantage is that the OCaml (and Haskell) compilers automatically infer
> > the correct type.
> >
> > In Java, you must always manually input the type, as far as I remember.
> 
> 
> i was under the impression, based on personal experience as well as
> hear-say, that anybody /really/ using haskell or ocaml or some such
> would actually be manually entering type signatures all the time,
> because they do not want to later have some incomprehensible error
> that does not point to a root cause.
[...]

It's possible (and possibly good style) to start with the signature.
If the problem is clear enough stated in the beginning.

Otherwise, it's possible to start with type inference as the helping tool,
and when the code is somewhat mature, create an mli-file to make things
less variable.

Which way to go depends on how much planning si done (and can be done)
in advcance.

But the talk had mentioned a lot more problems, not only type inference.
The comparision with unit testing also was nice. And many other aspects also.


Ciao,
   Oliver

Re: [Caml-list] How to explain static typing to other people?

[Florent Monnier]

2013/08/28, oliver wrote:
> Hello,
>
> did you ever get the response, that one could use Java,
> when you talked about the static typing advantages of
> languages like OCaml or Haskell?
>
> I often heard that and after trying to explain the differences
> for a while, I  started to stop the discussion, because the other person
> will not understand it. (Maybe it needs to be tried in the real world
> to see the differences... discussing about it alone can't work, I guess.)
[...]

sometimes a drawing (or something visual) is better than a long explanation:

http://www.ekobutiks.com/1551-thickbox/jouet-boite-a-formes-classic-goki-jouets-en-bois.jpg

From the beginning I understand the OCaml type system to be something
very similar to this child educational game.

-- 
Regards
Florent

Re: [Caml-list] How to explain static typing to other people?

[Johan Grande]

Le 28/08/2013 13:45, oliver a écrit :
> did you ever get the response, that one could use Java,
> when you talked about the static typing advantages of
> languages like OCaml or Haskell?

I haven't used Java in a while but if I remember correctly, although 
Java features static typing, it allows you to use not so safe tricks 
such as cast and null, while OCaml doesn't.

Moreover, OCaml allows to define complex types (and use them with 
pattern matching) very easily and thus makes you want to use the type 
system instead of trying to circumvent it.

type 'a option = Some 'a | None
How many lines to express that in Java?

OCaml's type inference is also very useful even if you choose to write 
some type information as good practice.

Last but not least, OCaml is a functional language. Well, I haven't 
tried Java 7.

-- 
Johan