[fpc-pascal] Re: What is the most widely used Pascal on Linux and other Unix variants?

[Sven Barth]

Am 28.02.2012 20:31, schrieb Lukasz Stafiniak:
> On Tue, Feb 28, 2012 at 8:22 AM, Noah Silva
> <shiruba at galapagossoftware.com>  wrote:
>>
>> If you want to convince people to use FPC and are having issues, you should
>> ask them what features, exactly, they are looking for.  Chances are that FPC
>> has them.  (If they want a functional language, though, then you're out of
>> luck).
>
> Pascal is not entirely opposed to being a functional language. There
> are two missing language features (consider it a proposal of
> Functional Pascal):
>
> (1) A declaration part, that parallels "var", with keyword "val" or
> "let" (since "val" is taken up by a procedure). It introduces named
> values, i.e. non-assignable variables. The part after "=" can be any
> expression. Therefore, this feature spoils the "declaration --
> implementation divide" that is dear to Pascal.

I personally don't see a use for this... but feel free to provide a 
useful example ;)

> (2) Closures. That is, making local functions that only use "const"
> arguments and "val / let" variables safe to return from the outer
> function. This can be done by allocating the "val / let" data on the
> heap, or perhaps easier by copying them into an implicitly built
> object and interpreting the returned local function as pointer to
> method of this object. The closure-object would be memory-managed as
> other objects.

Closures are already supported by Delphi 2009 and are currently being 
worked on by someone in FPC.

Regards,
Sven