Re: [Chicken-hackers] Unit files for chicken < 3.4.0 (was Re: [Chicken-users] Srfi-19 problems)

[felix winkelmann]

On Fri, Nov 7, 2008 at 8:02 PM, Mario Domenech Goulart
<address@hidden> wrote:
>>
>> The "files" unit came into existence with Chicken 3.4.0 (you are using
>> 3.3.0 I see). I suggest creating a empty extension "files" so
>> 'require' doesn't barf, upgrading Chicken, or using earlier versions
>> of eggs.
>
> This problem is very annoying.  To make the transition to the `files'
> unit era transparent to users, I thought about creating a `files' egg
> which only installs something[1] when (chicken-version) < 3.4.0,
> otherwise nothing is installed and the builtin `files' unit is used.
>
> [1] something like (use posix)
>
> So, when we are using chicken < 3.4.0 a files.so file is installed by
> chicken-setup.  The code of this file consists of requiring the
> `posix' unit.  When we have `(use files)' in the code, this extension
> is used.
>
> When we are using chicken >= 3.4.0, no file is installed.  When we
> have `(use files)' in the code, the `files' unit is used.
>
> All the eggs that use procedures from the `files' unit should require
> the `files' egg in their .meta file.
>
> Yes, that's an awful hack...  Any thoughts or better alternatives?
>

It's a hack, but it would work. Good idea, Mario.


cheers,
felix